Commit Graph

2819 Commits

Author SHA1 Message Date
Tejun Heo 1a40243bae tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks
printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:37 -08:00
Linus Torvalds 41cbc01f6e The updates included in this pull request for ftrace are:
o Several clean ups to the code
 
    One such clean up was to convert to 64 bit time keeping, in the
    ring buffer benchmark code.
 
  o Adding of __print_array() helper macro for TRACE_EVENT()
 
  o Updating the sample/trace_events/ to add samples of different ways to
    make trace events. Lots of features have been added since the sample
    code was made, and these features are mostly unknown. Developers
    have been making their own hacks to do things that are already available.
 
  o Performance improvements. Most notably, I found a performance bug where
    a waiter that is waiting for a full page from the ring buffer will
    see that a full page is not available, and go to sleep. The sched
    event caused by it going to sleep would cause it to wake up again.
    It would see that there was still not a full page, and go back to sleep
    again, and that would wake it up again, until finally it would see a
    full page. This change has been marked for stable.
 
    Other improvements include removing global locks from fast paths.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJU3M+GAAoJEEjnJuOKh9ldpWQIAJTUzeVXlU0cf3bVn768VW7e
 XS41WHF34l1tNevmKTh6fCPiw8+U0UMGLQt5WKtyaaARsZn2MlefLVuvHPKFlK2w
 +qcI4OEVHH97Qgf9HWJSsYgnZaOnOE+TENqnokEgXMimRMuVcd/S4QaGxwJVDcjm
 iBF5j2TaG4aGbx4a3J7KueoZ3K+39r3ut15hIGi/IZBZldQ1pt26ytafD/KA3CU3
 BLRM2HLttAMsV1ds0EDLgZjSGICVetFcdOmI5Gwj7Qr3KrOTRPYJMNc8NdDL7Js9
 v8VhujhFGvcCrhO/IKpVvd9yluz3RCF+Z7ihc+D/+1B3Nsm0PTwN3Fl5J+f89AA=
 =u2Mm
 -----END PGP SIGNATURE-----

Merge tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The updates included in this pull request for ftrace are:

   o Several clean ups to the code

     One such clean up was to convert to 64 bit time keeping, in the
     ring buffer benchmark code.

   o Adding of __print_array() helper macro for TRACE_EVENT()

   o Updating the sample/trace_events/ to add samples of different ways
     to make trace events.  Lots of features have been added since the
     sample code was made, and these features are mostly unknown.
     Developers have been making their own hacks to do things that are
     already available.

   o Performance improvements.  Most notably, I found a performance bug
     where a waiter that is waiting for a full page from the ring buffer
     will see that a full page is not available, and go to sleep.  The
     sched event caused by it going to sleep would cause it to wake up
     again.  It would see that there was still not a full page, and go
     back to sleep again, and that would wake it up again, until finally
     it would see a full page.  This change has been marked for stable.

  Other improvements include removing global locks from fast paths"

* tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Do not wake up a splice waiter when page is not full
  tracing: Fix unmapping loop in tracing_mark_write
  tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()
  tracing: Add TRACE_EVENT_FN example
  tracing: Add TRACE_EVENT_CONDITION sample
  tracing: Update the TRACE_EVENT fields available in the sample code
  tracing: Separate out initializing top level dir from instances
  tracing: Make tracing_init_dentry_tr() static
  trace: Use 64-bit timekeeping
  tracing: Add array printing helper
  tracing: Remove newline from trace_printk warning banner
  tracing: Use IS_ERR() check for return value of tracing_init_dentry()
  tracing: Remove unneeded includes of debugfs.h and fs.h
  tracing: Remove taking of trace_types_lock in pipe files
  tracing: Add ref count to tracer for when they are being read by pipe
2015-02-12 08:37:41 -08:00
Linus Torvalds b3d6524ff7 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:

 - The remaining patches for the z13 machine support: kernel build
   option for z13, the cache synonym avoidance, SMT support,
   compare-and-delay for spinloops and the CES5S crypto adapater.

 - The ftrace support for function tracing with the gcc hotpatch option.
   This touches common code Makefiles, Steven is ok with the changes.

 - The hypfs file system gets an extension to access diagnose 0x0c data
   in user space for performance analysis for Linux running under z/VM.

 - The iucv hvc console gets wildcard spport for the user id filtering.

 - The cacheinfo code is converted to use the generic infrastructure.

 - Cleanup and bug fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
  s390/process: free vx save area when releasing tasks
  s390/hypfs: Eliminate hypfs interval
  s390/hypfs: Add diagnose 0c support
  s390/cacheinfo: don't use smp_processor_id() in preemptible context
  s390/zcrypt: fixed domain scanning problem (again)
  s390/smp: increase maximum value of NR_CPUS to 512
  s390/jump label: use different nop instruction
  s390/jump label: add sanity checks
  s390/mm: correct missing space when reporting user process faults
  s390/dasd: cleanup profiling
  s390/dasd: add locking for global_profile access
  s390/ftrace: hotpatch support for function tracing
  ftrace: let notrace function attribute disable hotpatching if necessary
  ftrace: allow architectures to specify ftrace compile options
  s390: reintroduce diag 44 calls for cpu_relax()
  s390/zcrypt: Add support for new crypto express (CEX5S) adapter.
  s390/zcrypt: Number of supported ap domains is not retrievable.
  s390/spinlock: add compare-and-delay to lock wait loops
  s390/tape: remove redundant if statement
  s390/hvc_iucv: add simple wildcard matches to the iucv allow filter
  ...
2015-02-11 17:42:32 -08:00
Steven Rostedt (Red Hat) 1e0d6714ac ring-buffer: Do not wake up a splice waiter when page is not full
When an application connects to the ring buffer via splice, it can only
read full pages. Splice does not work with partial pages. If there is
not enough data to fill a page, the splice command will either block
or return -EAGAIN (if set to nonblock).

Code was added where if the page is not full, to just sleep again.
The problem is, it will get woken up again on the next event. That
is, when something is written into the ring buffer, if there is a waiter
it will wake it up. The waiter would then check the buffer, see that
it still does not have enough data to fill a page and go back to sleep.
To make matters worse, when the waiter goes back to sleep, it could
cause another event, which would wake it back up again to see it
doesn't have enough data and sleep again. This produces a tremendous
overhead and fills the ring buffer with noise.

For example, recording sched_switch on an idle system for 10 seconds
produces 25,350,475 events!!!

Create another wait queue for those waiters wanting full pages.
When an event is written, it only wakes up waiters if there's a full
page of data. It does not wake up the waiter if the page is not yet
full.

After this change, recording sched_switch on an idle system for 10
seconds produces only 800 events. Getting rid of 25,349,675 useless
events (99.9969% of events!!), is something to take seriously.

Cc: stable@vger.kernel.org # 3.16+
Cc: Rabin Vincent <rabin@rab.in>
Fixes: e30f53aad2 "tracing: Do not busy wait in buffer splice"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-11 07:41:42 -05:00
Linus Torvalds 872912352c ACPI and power management updates for v3.20-rc1
- Rework of the core ACPI resources parsing code to fix issues
    in it and make using resource offsets more convenient and
    consolidation of some resource-handing code in a couple of places
    that have grown analagous data structures and code to cover the
    the same gap in the core (Jiang Liu, Thomas Gleixner, Lv Zheng).
 
  - ACPI-based IOAPIC hotplug support on top of the resources handling
    rework (Jiang Liu, Yinghai Lu).
 
  - ACPICA update to upstream release 20150204 including an interrupt
    handling rework that allows drivers to install raw handlers for
    ACPI GPEs which then become entirely responsible for the given GPE
    and the ACPICA core code won't touch it (Lv Zheng, David E Box,
    Octavian Purdila).
 
  - ACPI EC driver rework to fix several concurrency issues and other
    problems related to events handling on top of the ACPICA's new
    support for raw GPE handlers (Lv Zheng).
 
  - New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
    Subsystem) driver for Intel chips (Ken Xue).
 
  - Two minor fixes of the ACPI LPSS driver (Heikki Krogerus,
    Jarkko Nikula).
 
  - Two new blacklist entries for machines (Samsung 730U3E/740U3E and
    510R) where the native backlight interface doesn't work correctly
    while the ACPI one does (Hans de Goede).
 
  - Rework of the ACPI processor driver's handling of idle states
    to make the code more straightforward and less bloated overall
    (Rafael J Wysocki).
 
  - Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
    Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki,
    Yaowei Bai).
 
  - PCI core power management modification to avoid resuming (some)
    runtime-suspended devices during system suspend if they are in
    the right states already (Rafael J Wysocki).
 
  - New SFI-based cpufreq driver for Intel platforms using SFI
    (Srinidhi Kasagar).
 
  - cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
    Doug Anderson, Wolfram Sang).
 
  - SkyLake CPU support and other updates for the intel_pstate driver
    (Kristen Carlson Accardi, Srinivas Pandruvada).
 
  - cpufreq-dt driver cleanup (Markus Elfring).
 
  - Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).
 
  - Generic power domains core code fixes and cleanups (Ulf Hansson).
 
  - Operating Performance Points (OPP) core code cleanups and kernel
    documentation update (Nishanth Menon).
 
  - New dabugfs interface to make the list of PM QoS constraints
    available to user space (Nishanth Menon).
 
  - New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).
 
  - New devfreq class (devfreq_event) to provide raw utilization data
    to devfreq governors (Chanwoo Choi).
 
  - Assorted minor fixes and cleanups related to power management
    (Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist,
    Pavel Machek, Todd E Brandt, Wonhong Kwon).
 
  - turbostat updates (Len Brown) and cpupower Makefile improvement
    (Sriram Raghunathan).
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJU2neOAAoJEILEb/54YlRx51QP/jrv1Wb5eMaemzMksPIWI5Zn
 I8IbxzToxu7wDDsrTBRv+LuyllMPrnppFOHHvB35gUYu7Y6I066s3ErwuqeFlbmy
 +VicmyGMahv3yN74qg49MXzWtaJZa8hrFXn8ItujiUIcs08yELi0vBQFlZImIbTB
 PdQngO88VfiOVjDvmKkYUU//9Sc9LCU0ZcdUQXSnA1oNOxuUHjiARz98R03hhSqu
 BWR+7M0uaFbu6XeK+BExMXJTpKicIBZ1GAF6hWrS8V4aYg+hH1cwjf2neDAzZkcU
 UkXieJlLJrCq+ZBNcy7WEhkWQkqJNWei5WYiy6eoQeQpNoliY2V+2OtSMJaKqDye
 PIiMwXstyDc5rgyULN0d1UUzY6mbcUt2rOL0VN2bsFVIJ1HWCq8mr8qq689pQUYv
 tcH18VQ2/6r2zW28sTO/ByWLYomklD/Y6bw2onMhGx3Knl0D8xYJKapVnTGhr5eY
 d4k41ybHSWNKfXsZxdJc+RxndhPwj9rFLfvY/CZEhLcW+2pAiMarRDOPXDoUI7/l
 aJpmPzy/6mPXGBnTfr6jKDSY3gXNazRIvfPbAdiGayKcHcdRM4glbSbNH0/h1Iq6
 HKa8v9Fx87k1X5r4ZbhiPdABWlxuKDiM7725rfGpvjlWC3GNFOq7YTVMOuuBA225
 Mu9PRZbOsZsnyNkixBpX
 =zZER
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "We have a few new features this time, including a new SFI-based
  cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new
  devfreq class for providing its governors with raw utilization data
  and a new ACPI driver for AMD SoCs.

  Still, the majority of changes here are reworks of existing code to
  make it more straightforward or to prepare it for implementing new
  features on top of it.  The primary example is the rework of ACPI
  resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with
  support for IOAPIC hotplug implemented on top of it, but there is
  quite a number of changes of this kind in the cpufreq core, ACPICA,
  ACPI EC driver, ACPI processor driver and the generic power domains
  core code too.

  The most active developer is Viresh Kumar with his cpufreq changes.

  Specifics:

   - Rework of the core ACPI resources parsing code to fix issues in it
     and make using resource offsets more convenient and consolidation
     of some resource-handing code in a couple of places that have grown
     analagous data structures and code to cover the the same gap in the
     core (Jiang Liu, Thomas Gleixner, Lv Zheng).

   - ACPI-based IOAPIC hotplug support on top of the resources handling
     rework (Jiang Liu, Yinghai Lu).

   - ACPICA update to upstream release 20150204 including an interrupt
     handling rework that allows drivers to install raw handlers for
     ACPI GPEs which then become entirely responsible for the given GPE
     and the ACPICA core code won't touch it (Lv Zheng, David E Box,
     Octavian Purdila).

   - ACPI EC driver rework to fix several concurrency issues and other
     problems related to events handling on top of the ACPICA's new
     support for raw GPE handlers (Lv Zheng).

   - New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
     Subsystem) driver for Intel chips (Ken Xue).

   - Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko
     Nikula).

   - Two new blacklist entries for machines (Samsung 730U3E/740U3E and
     510R) where the native backlight interface doesn't work correctly
     while the ACPI one does (Hans de Goede).

   - Rework of the ACPI processor driver's handling of idle states to
     make the code more straightforward and less bloated overall (Rafael
     J Wysocki).

   - Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
     Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei
     Bai).

   - PCI core power management modification to avoid resuming (some)
     runtime-suspended devices during system suspend if they are in the
     right states already (Rafael J Wysocki).

   - New SFI-based cpufreq driver for Intel platforms using SFI
     (Srinidhi Kasagar).

   - cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
     Doug Anderson, Wolfram Sang).

   - SkyLake CPU support and other updates for the intel_pstate driver
     (Kristen Carlson Accardi, Srinivas Pandruvada).

   - cpufreq-dt driver cleanup (Markus Elfring).

   - Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).

   - Generic power domains core code fixes and cleanups (Ulf Hansson).

   - Operating Performance Points (OPP) core code cleanups and kernel
     documentation update (Nishanth Menon).

   - New dabugfs interface to make the list of PM QoS constraints
     available to user space (Nishanth Menon).

   - New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).

   - New devfreq class (devfreq_event) to provide raw utilization data
     to devfreq governors (Chanwoo Choi).

   - Assorted minor fixes and cleanups related to power management
     (Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel
     Machek, Todd E Brandt, Wonhong Kwon).

   - turbostat updates (Len Brown) and cpupower Makefile improvement
     (Sriram Raghunathan)"

* tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits)
  tools/power turbostat: relax dependency on APERF_MSR
  tools/power turbostat: relax dependency on invariant TSC
  Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
  tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS
  tools/power turbostat: relax dependency on root permission
  ACPI / video: Add disable_native_backlight quirk for Samsung 510R
  ACPI / PM: Remove unneeded nested #ifdef
  USB / PM: Remove unneeded #ifdef and associated dead code
  intel_pstate: provide option to only use intel_pstate with HWP
  ACPI / EC: Add GPE reference counting debugging messages
  ACPI / EC: Add query flushing support
  ACPI / EC: Refine command storm prevention support
  ACPI / EC: Add command flushing support.
  ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag
  ACPI: add AMD ACPI2Platform device support for x86 system
  ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
  ACPI / EC: Update revision due to raw handler mode.
  ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
  ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
  ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
  ...
2015-02-10 15:09:41 -08:00
Vikram Mulukutla 7215853e98 tracing: Fix unmapping loop in tracing_mark_write
Commit 6edb2a8a38 introduced
an array map_pages that contains the addresses returned by
kmap_atomic. However, when unmapping those pages, map_pages[0]
is unmapped before map_pages[1], breaking the nesting requirement
as specified in the documentation for kmap_atomic/kunmap_atomic.

This was caught by the highmem debug code present in kunmap_atomic.
Fix the loop to do the unmapping properly.

Link: http://lkml.kernel.org/r/1418871056-6614-1-git-send-email-markivx@codeaurora.org

Cc: stable@vger.kernel.org # 3.5+
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reported-by: Lime Yang <limey@codeaurora.org>
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-09 18:47:09 -05:00
Steven Rostedt (Red Hat) 7eeafbcab4 tracing: Separate out initializing top level dir from instances
The top level trace array is treated a little different than the
instances, as it has to deal with more of the general tracing.
The tr->dir is the tracing directory, which is an immutable
dentry, where as the tr->dir of instances are the dentry that
was created, and can be destroyed later. These should have different
functions accessing them.

As only tracing_init_dentry() deals with the top level array, fold
the code for it into that function, and remove the trace_init_dentry_tr()
that was also used by the instances to get their directory dentry.

Add a tracing_get_dentry() to just get the tracing dir entry for
instances as well as the top level array.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-02 10:22:34 -05:00
Steven Rostedt (Red Hat) c602894814 tracing: Make tracing_init_dentry_tr() static
tracing_init_dentry_tr() is not used outside of trace.c, it should
be static.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-02 10:22:23 -05:00
Todd E Brandt c9257f78b4 PM / sleep: export suspend_resume trace event
Export the suspend_resume tracepoint so it can be used
in loadable modules.

Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-30 02:10:41 +01:00
Heiko Carstens c0a80c0c27 ftrace: allow architectures to specify ftrace compile options
If the kernel is compiled with function tracer support the -pg compile option
is passed to gcc to generate extra code into the prologue of each function.

This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE
makefile variable which architectures can override if a different option
should be used for code generation.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-29 09:19:19 +01:00
Tina Ruchandani da194930ed trace: Use 64-bit timekeeping
The ring_buffer_producer uses 'struct timeval' to measure
its start and end times. 'struct timeval' on 32-bit systems
will have its tv_sec value overflow in year 2038 and beyond.
This patch replaces struct timeval with 'ktime_t' which uses
64-bit representation for nanoseconds.

Link: http://lkml.kernel.org/r/20150128141611.GA2701@tinar

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-28 11:02:05 -05:00
Dave Martin 6ea22486ba tracing: Add array printing helper
If a trace event contains an array, there is currently no standard
way to format this for text output.  Drivers are currently hacking
around this by a) local hacks that use the trace_seq functionailty
directly, or b) just not printing that information.  For fixed size
arrays, formatting of the elements can be open-coded, but this gets
cumbersome for arrays of non-trivial size.

These approaches result in non-standard content of the event format
description delivered to userspace, so userland tools needs to be
taught to understand and parse each array printing method
individually.

This patch implements a __print_array() helper that tracepoint
implementations can use instead of reinventing it.  A simple C-style
syntax is used to delimit the array and its elements {like,this}.

So that the helpers can be used with large static arrays as well as
dynamic arrays, they take a pointer and element count: they can be
used with __get_dynamic_array() for use with dynamic arrays.
Link: http://lkml.kernel.org/r/1422449335-8289-2-git-send-email-javi.merino@arm.com

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-28 10:34:47 -05:00
Ingo Molnar f10698ed68 Merge branch 'perf/urgent' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-28 15:42:56 +01:00
Borislav Petkov 69a1c994cc tracing: Remove newline from trace_printk warning banner
Remove the output-confusing newline below:

[    0.191328]
**********************************************************
[    0.191493] **   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
[    0.191586] **                                                      **
...

Link: http://lkml.kernel.org/r/1422375440-31970-1-git-send-email-bp@alien8.de

Signed-off-by: Borislav Petkov <bp@suse.de>
[ added an extra '\n' by itself, to keep what it was suppose to do ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-27 17:51:24 -05:00
Steven Rostedt (Red Hat) 14a5ae40f0 tracing: Use IS_ERR() check for return value of tracing_init_dentry()
tracing_init_dentry() will soon return NULL as a valid pointer for the
top level tracing directroy. NULL can not be used as an error value.
Instead, switch to ERR_PTR() and check the return status with
IS_ERR().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-22 11:19:49 -05:00
Steven Rostedt (Red Hat) 3efb5f21a3 tracing: Remove unneeded includes of debugfs.h and fs.h
The creation of tracing files and directories is for the most part
encapsulated in helper functions in trace.c. Other files do not need to
include debugfs.h or fs.h, as they may have needed to in the past.

Remove them from the files that do not need them.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-22 11:19:48 -05:00
Linus Torvalds 23aa4b416a This holds a few fixes to the ftrace infrastructure as well as
the mixture of function graph tracing and kprobes.
 
 When jprobes and function graph tracing is enabled at the same time
 it will crash the system.
 
   # modprobe jprobe_example
   # echo function_graph > /sys/kernel/debug/tracing/current_tracer
 
 After the first fork (jprobe_example probes it), the system will crash.
 This is due to the way jprobes copies the stack frame and does not
 do a normal function return. This messes up with the function graph
 tracing accounting which hijacks the return address from the stack
 and replaces it with a hook function. It saves the return addresses in
 a separate stack to put back the correct return address when done.
 But because the jprobe functions do not do a normal return, their
 stack addresses are not put back until the function they probe is called,
 which means that the probed function will get the return address of
 the jprobe handler instead of its own.
 
 The simple fix here was to disable function graph tracing while the
 jprobe handler is being called.
 
 While debugging this I found two minor bugs with the function graph
 tracing.
 
 The first was about the function graph tracer sharing its function hash
 with the function tracer (they both get filtered by the same input).
 The changing of the set_ftrace_filter would not sync the function recording
 records after a change if the function tracer was disabled but the
 function graph tracer was enabled. This was due to the update only checking
 one of the ops instead of the shared ops to see if they were enabled and
 should perform the sync. This caused the ftrace accounting to break and
 a ftrace_bug() would be triggered, disabling ftrace until a reboot.
 
 The second was that the check to update records only checked one of the
 filter hashes. It needs to test both the "filter" and "notrace" hashes.
 The "filter" hash determines what functions to trace where as the "notrace"
 hash determines what functions not to trace (trace all but these).
 Both hashes need to be passed to the update code to find out what change
 is being done during the update. This also broke the ftrace record
 accounting and triggered a ftrace_bug().
 
 This patch set also include two more fixes that were reported separately
 from the kprobe issue.
 
 One was that init_ftrace_syscalls() was called twice at boot up.
 This is not a major bug, but that call performed a rather large kmalloc
 (NR_syscalls * sizeof(*syscalls_metadata)). The second call made the first
 one a memory leak, and wastes memory.
 
 The other fix is a regression caused by an update in the v3.19 merge window.
 The moving to enable events early, moved the enabling before PID 1 was
 created. The syscall events require setting the TIF_SYSCALL_TRACEPOINT
 for all tasks. But for_each_process_thread() does not include the swapper
 task (PID 0), and ended up being a nop. A suggested fix was to add
 the init_task() to have its flag set, but I didn't really want to mess
 with PID 0 for this minor bug. Instead I disable and re-enable events again
 at early_initcall() where it use to be enabled. This also handles any other
 event that might have its own reg function that could break at early
 boot up.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUt9vmAAoJEEjnJuOKh9ldLHEIAJ9XrPW2xMIY5yI69jT1F7pv
 PkSRqENnOK0l4UulD52SvIBecQTTBcEEjao4yVGkc7DCJBOws/1LZ5gW8OfNlKjq
 rMB8yaosL1tXJ1ARVPMjcQVy+228zkgTXznwEZCjku1g7LuScQ28qyXsXO7B6yiK
 xKoHqKjygmM/a2aVn+8tdiVKiDp6jdmkbYicbaFT4xP7XB5DaMmIiXRHxdvW6xdR
 azKrVfYiMyJqTZNt/EVSWUk2WjeaYhoXyNtvgPx515wTo/llCnzhjcsocXBtH2P/
 YOtwl+1L7Z89ukV9oXqrtrUJZ6Ps7+g7I1flJuL7/1FlNGnklcP9JojD+t6HeT8=
 =vkec
 -----END PGP SIGNATURE-----

Merge tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace fixes from Steven Rostedt:
 "This holds a few fixes to the ftrace infrastructure as well as the
  mixture of function graph tracing and kprobes.

  When jprobes and function graph tracing is enabled at the same time it
  will crash the system:

      # modprobe jprobe_example
      # echo function_graph > /sys/kernel/debug/tracing/current_tracer

  After the first fork (jprobe_example probes it), the system will
  crash.

  This is due to the way jprobes copies the stack frame and does not do
  a normal function return.  This messes up with the function graph
  tracing accounting which hijacks the return address from the stack and
  replaces it with a hook function.  It saves the return addresses in a
  separate stack to put back the correct return address when done.  But
  because the jprobe functions do not do a normal return, their stack
  addresses are not put back until the function they probe is called,
  which means that the probed function will get the return address of
  the jprobe handler instead of its own.

  The simple fix here was to disable function graph tracing while the
  jprobe handler is being called.

  While debugging this I found two minor bugs with the function graph
  tracing.

  The first was about the function graph tracer sharing its function
  hash with the function tracer (they both get filtered by the same
  input).  The changing of the set_ftrace_filter would not sync the
  function recording records after a change if the function tracer was
  disabled but the function graph tracer was enabled.  This was due to
  the update only checking one of the ops instead of the shared ops to
  see if they were enabled and should perform the sync.  This caused the
  ftrace accounting to break and a ftrace_bug() would be triggered,
  disabling ftrace until a reboot.

  The second was that the check to update records only checked one of
  the filter hashes.  It needs to test both the "filter" and "notrace"
  hashes.  The "filter" hash determines what functions to trace where as
  the "notrace" hash determines what functions not to trace (trace all
  but these).  Both hashes need to be passed to the update code to find
  out what change is being done during the update.  This also broke the
  ftrace record accounting and triggered a ftrace_bug().

  This patch set also include two more fixes that were reported
  separately from the kprobe issue.

  One was that init_ftrace_syscalls() was called twice at boot up.  This
  is not a major bug, but that call performed a rather large kmalloc
  (NR_syscalls * sizeof(*syscalls_metadata)).  The second call made the
  first one a memory leak, and wastes memory.

  The other fix is a regression caused by an update in the v3.19 merge
  window.  The moving to enable events early, moved the enabling before
  PID 1 was created.  The syscall events require setting the
  TIF_SYSCALL_TRACEPOINT for all tasks.  But for_each_process_thread()
  does not include the swapper task (PID 0), and ended up being a nop.

  A suggested fix was to add the init_task() to have its flag set, but I
  didn't really want to mess with PID 0 for this minor bug.  Instead I
  disable and re-enable events again at early_initcall() where it use to
  be enabled.  This also handles any other event that might have its own
  reg function that could break at early boot up"

* tag 'trace-fixes-v3.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix enabling of syscall events on the command line
  tracing: Remove extra call to init_ftrace_syscalls()
  ftrace/jprobes/x86: Fix conflict between jprobes and function graph tracing
  ftrace: Check both notrace and filter for old hash
  ftrace: Fix updating of filters for shared global_ops filters
2015-01-17 07:55:52 +13:00
Steven Rostedt (Red Hat) ce1039bd3a tracing: Fix enabling of syscall events on the command line
Commit 5f893b2639 "tracing: Move enabling tracepoints to just after
rcu_init()" broke the enabling of system call events from the command
line. The reason was that the enabling of command line trace events
was moved before PID 1 started, and the syscall tracepoints require
that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the
swapper task (pid 0) is not part of that. Since the swapper task is the
only task that is running at this early in boot, no task gets the
flag set, and the tracepoint never gets reached.

Instead of setting the swapper task flag (there should be no reason to
do that), re-enabled trace events again after the init thread (PID 1)
has been started. It requires disabling all command line events and
re-enabling them, as just enabling them again will not reset the logic
to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will
be fooled into thinking that it was already set, and wont try setting
it again. For this reason, we must first disable it and re-enable it.

Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org

Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:42:50 -05:00
Steven Rostedt (Red Hat) 83829b74f5 tracing: Remove extra call to init_ftrace_syscalls()
trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().

Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.

Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org

Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:41:11 -05:00
Steven Rostedt (Red Hat) 7485058eea ftrace: Check both notrace and filter for old hash
Using just the filter for checking for trampolines or regs is not enough
when updating the code against the records that represent all functions.
Both the filter hash and the notrace hash need to be checked.

To trigger this bug (using trace-cmd and perf):

 # perf probe -a do_fork
 # trace-cmd start -B foo -e probe
 # trace-cmd record -p function_graph -n do_fork sleep 1

The trace-cmd record at the end clears the filter before it disables
function_graph tracing and then that causes the accounting of the
ftrace function records to become incorrect and causes ftrace to bug.

Link: http://lkml.kernel.org/r/20150114154329.358378039@goodmis.org

Cc: stable@vger.kernel.org
[ still need to switch old_hash_ops to old_ops_hash ]
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:37:33 -05:00
Steven Rostedt (Red Hat) 8f86f83709 ftrace: Fix updating of filters for shared global_ops filters
As the set_ftrace_filter affects both the function tracer as well as the
function graph tracer, the ops that represent each have a shared
ftrace_ops_hash structure. This allows both to be updated when the filter
files are updated.

But if function graph is enabled and the global_ops (function tracing) ops
is not, then it is possible that the filter could be changed without the
update happening for the function graph ops. This will cause the changes
to not take place and may even cause a ftrace_bug to occur as it could mess
with the trampoline accounting.

The solution is to check if the ops uses the shared global_ops filter and
if the ops itself is not enabled, to check if there's another ops that is
enabled and also shares the global_ops filter. In that case, the
modification still needs to be executed.

Link: http://lkml.kernel.org/r/20150114154329.055980438@goodmis.org

Cc: stable@vger.kernel.org # 3.17+
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15 09:37:07 -05:00
Peter Zijlstra (Intel) 86038c5ea8 perf: Avoid horrible stack usage
Both Linus (most recent) and Steve (a while ago) reported that perf
related callbacks have massive stack bloat.

The problem is that software events need a pt_regs in order to
properly report the event location and unwind stack. And because we
could not assume one was present we allocated one on stack and filled
it with minimal bits required for operation.

Now, pt_regs is quite large, so this is undesirable. Furthermore it
turns out that most sites actually have a pt_regs pointer available,
making this even more onerous, as the stack space is pointless waste.

This patch addresses the problem by observing that software events
have well defined nesting semantics, therefore we can use static
per-cpu storage instead of on-stack.

Linus made the further observation that all but the scheduler callers
of perf_sw_event() have a pt_regs available, so we change the regular
perf_sw_event() to require a valid pt_regs (where it used to be
optional) and add perf_sw_event_sched() for the scheduler.

We have a scheduler specific call instead of a more generic _noregs()
like construct because we can assume non-recursion from the scheduler
and thereby simplify the code further (_noregs would have to put the
recursion context call inline in order to assertain which __perf_regs
element to use).

One last note on the implementation of perf_trace_buf_prepare(); we
allow .regs = NULL for those cases where we already have a pt_regs
pointer available and do not need another.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Javi Merino <javi.merino@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-14 15:11:45 +01:00
Linus Torvalds aa9291355e KGDB/KDB fixes and cleanups
Cleanups
    kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE
 
  Fixes
    kgdb/kdb: Allow access on a single core, if a CPU round up is deemed
       impossible, which will allow inspection of the now "trashed" kernel
    kdb: Add enable mask for the command groups
    kdb: access controls to restrict sensitive commands
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUrq8WAAoJEIciOldedpOj+C8P/AjSUVBZdBLWzCU2VG150sQ0
 UacwFVLve9heoColHBF7VqIDCRkZokIKJmCbHUBPZTbs22auLRpNI+D6CY5lZD17
 jEHxrkKY4ragRRc/W3Y1MSc3aeGnS0i5AR8PJermMWxyUBfN3FBxgFHzTaLB2ZTT
 8A+tvmwiG4mHue52gSiYZPCl/52WWOh+NjDe7T9OZ+mNmQKwZ5ssQZmmyUkxrs3b
 LKXVXVtTUXxfEgB2x+lYTYAztcTsM5h+NbkT74FpSmwPjvU/p81Ptqveh+3JTdmX
 H+Jz/SqD1/NfxC1Eenh5Mc++p/UVxeRbBulV9jwqjOyJqDjw3qHs1cjm8tZZj1qG
 J3LODKi3GWhujMCfwdu5EJRnrFxgHCPiWInc2708oLbRi5SyOe6P6hNQ3K3Y4JtF
 VkYa62wSaI0fDNQUFRc3bXUOUdMOCXjuzw3BtTi93tcUNcQwCXuYCmWtVvBgmK1h
 LTrFCJmzbopiwpomxCwZ4BQm8id9HxP5pod95ypYb8K5aheXHCuSgibqj0nswWMm
 ix0YTd4UNTn79r6p4d0fXFjOOYpXZA80ojeVI27D9zW7dBYc5CGVA1IDNH0ZfiPo
 qySPUNUMXIjiTSOGZdUehByEC7tliLZczelRPnNh/9fmhJkJ745S7zs3DNQ7Ypg4
 xDKthlRGNjn6cXOPl7gX
 =cf1c
 -----END PGP SIGNATURE-----

Merge tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

Pull kgdb/kdb fixes from Jason Wessel:
 "These have been around since 3.17 and in kgdb-next for the last 9
  weeks and some will go back to -stable.

  Summary of changes:

  Cleanups
   - kdb: Remove unused command flags, repeat flags and KDB_REPEAT_NONE

  Fixes
   - kgdb/kdb: Allow access on a single core, if a CPU round up is
     deemed impossible, which will allow inspection of the now "trashed"
     kernel
   - kdb: Add enable mask for the command groups
   - kdb: access controls to restrict sensitive commands"

* tag 'for_linus-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kernel/debug/debug_core.c: Logging clean-up
  kgdb: timeout if secondary CPUs ignore the roundup
  kdb: Allow access to sensitive commands to be restricted by default
  kdb: Add enable mask for groups of commands
  kdb: Categorize kdb commands (similar to SysRq categorization)
  kdb: Remove KDB_REPEAT_NONE flag
  kdb: Use KDB_REPEAT_* values as flags
  kdb: Rename kdb_register_repeat() to kdb_register_flags()
  kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
  kdb: Remove currently unused kdbtab_t->cmd_flags
2015-01-09 20:51:10 -08:00
Steven Rostedt (Red Hat) d716ff71dd tracing: Remove taking of trace_types_lock in pipe files
Taking the global mutex "trace_types_lock" in the trace_pipe files
causes a bottle neck as most the pipe files can be read per cpu
and there's no reason to serialize them.

The current_trace variable was given a ref count and it can not
change when the ref count is not zero. Opening the trace_pipe
files will up the ref count (and decremented on close), so that
the lock no longer needs to be taken when accessing the
current_trace variable.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-22 23:37:46 -05:00
Steven Rostedt (Red Hat) cf6ab6d914 tracing: Add ref count to tracer for when they are being read by pipe
When one of the trace pipe files are being read (by either the trace_pipe
or trace_pipe_raw), do not allow the current_trace to change. By adding
a ref count that is incremented when the pipe files are opened, will
prevent the current_trace from being changed.

This will allow for the removal of the global trace_types_lock from
reading the pipe buffers (which is currently a bottle neck).

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-22 15:39:40 -05:00
Linus Torvalds c0f486fde3 More ACPI and power management updates for 3.19-rc1
- Fix a regression in leds-gpio introduced by a recent commit that
    inadvertently changed the name of one of the properties used by
    the driver (Fabio Estevam).
 
  - Fix a regression in the ACPI backlight driver introduced by a
    recent fix that missed one special case that had to be taken
    into account (Aaron Lu).
 
  - Drop the level of some new kernel messages from the ACPI core
    introduced by a recent commit to KERN_DEBUG which they should
    have used from the start and drop some other unuseful KERN_ERR
    messages printed by ACPI (Rafael J Wysocki).
 
  - Revert an incorrect commit modifying the cpupower tool
    (Prarit Bhargava).
 
  - Fix two regressions introduced by recent commits in the OPP
    library and clean up some existing minor issues in that code
    (Viresh Kumar).
 
  - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout
    the tree (or drop it where that can be done) in order to make
    it possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki,
    Ulf Hansson, Ludovic Desroches).  There will be one more
    "CONFIG_PM_RUNTIME removal" batch after this one, because some
    new uses of it have been introduced during the current merge
    window, but that should be sufficient to finally get rid of it.
 
  - Make the ACPI EC driver more robust against race conditions
    related to GPE handler installation failures (Lv Zheng).
 
  - Prevent the ACPI device PM core code from attempting to
    disable GPEs that it has not enabled which confuses ACPICA
    and makes it report errors unnecessarily (Rafael J Wysocki).
 
  - Add a "force" command line switch to the intel_pstate driver
    to make it possible to override the blacklisting of some
    systems in that driver if needed (Ethan Zhao).
 
  - Improve intel_pstate code documentation and add a MAINTAINERS
    entry for it (Kristen Carlson Accardi).
 
  - Make the ACPI fan driver create cooling device interfaces
    witn names that reflect the IDs of the ACPI device objects
    they are associated with, except for "generic" ACPI fans
    (PNP ID "PNP0C0B").  That's necessary for user space thermal
    management tools to be able to connect the fans with the
    parts of the system they are supposed to be cooling properly.
    From Srinivas Pandruvada.
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABCAAGBQJUk0IDAAoJEILEb/54YlRx7fgP/3+yF/0TnEW93j2ALDAQFiLF
 tSv2A2vQC8vtMJjjWx0z/HqPh86gfaReEFZmUJD/Q/e2LXEnxNZJ+QMjcekPVkDM
 mTvcIMc2MR8vOA/oMkgxeaKregrrx7RkCfojd+NWZhVukkjl+mvBHgAnYjXRL+NZ
 unDWGlbHG97vq/3kGjPYhDS00nxHblw8NHFBu5HL5RxwABdWoeZJITwqxXWyuPLw
 nlqNWlOxmwvtSbw2VMKz0uof1nFHyQLykYsMG0ZsyayCRdWUZYkEqmE7GGpCLkLu
 D6yfmlpen6ccIOsEAae0eXBt50IFY9Tihk5lovx1mZmci2SNRg29BqMI105wIn0u
 8b8Ej7MNHp7yMxRpB5WfU90p/y7ioJns9guFZxY0CKaRnrI2+BLt3RscMi3MPI06
 Cu2/WkSSa09fhDPA+pk+VDYsmWgyVawigesNmMP5/cvYO/yYywVRjOuO1k77qQGp
 4dSpFYEHfpxinejZnVZOk2V9MkvSLoSMux6wPV0xM0IE1iD0ulVpHjTJrwp80ph4
 +bfUFVr/vrD1y7EKbf1PD363ZKvJhWhvQWDgETsM1vgLf21PfWO7C2kflIAsWsdQ
 1ukD5nCBRlP4K73hG7bdM6kRztXhUdR0SHg85/t0KB/ExiVqtcXIzB60D0G1lENd
 QlKbq3O4lim1WGuhazQY
 =5fo2
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI and power management updates from Rafael Wysocki:
 "These are regression fixes (leds-gpio, ACPI backlight driver,
  operating performance points library, ACPI device enumeration
  messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
  PM), some cleanups in the operating performance points (OPP)
  framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
  minor intel_pstate driver changes, a new MAINTAINERS entry for it and
  an ACPI fan driver change needed for better support of thermal
  management in user space.

  Specifics:

   - Fix a regression in leds-gpio introduced by a recent commit that
     inadvertently changed the name of one of the properties used by the
     driver (Fabio Estevam).

   - Fix a regression in the ACPI backlight driver introduced by a
     recent fix that missed one special case that had to be taken into
     account (Aaron Lu).

   - Drop the level of some new kernel messages from the ACPI core
     introduced by a recent commit to KERN_DEBUG which they should have
     used from the start and drop some other unuseful KERN_ERR messages
     printed by ACPI (Rafael J Wysocki).

   - Revert an incorrect commit modifying the cpupower tool (Prarit
     Bhargava).

   - Fix two regressions introduced by recent commits in the OPP library
     and clean up some existing minor issues in that code (Viresh
     Kumar).

   - Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
     tree (or drop it where that can be done) in order to make it
     possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
     Hansson, Ludovic Desroches).

     There will be one more "CONFIG_PM_RUNTIME removal" batch after this
     one, because some new uses of it have been introduced during the
     current merge window, but that should be sufficient to finally get
     rid of it.

   - Make the ACPI EC driver more robust against race conditions related
     to GPE handler installation failures (Lv Zheng).

   - Prevent the ACPI device PM core code from attempting to disable
     GPEs that it has not enabled which confuses ACPICA and makes it
     report errors unnecessarily (Rafael J Wysocki).

   - Add a "force" command line switch to the intel_pstate driver to
     make it possible to override the blacklisting of some systems in
     that driver if needed (Ethan Zhao).

   - Improve intel_pstate code documentation and add a MAINTAINERS entry
     for it (Kristen Carlson Accardi).

   - Make the ACPI fan driver create cooling device interfaces witn
     names that reflect the IDs of the ACPI device objects they are
     associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").

     That's necessary for user space thermal management tools to be able
     to connect the fans with the parts of the system they are supposed
     to be cooling properly.  From Srinivas Pandruvada"

* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  MAINTAINERS: add entry for intel_pstate
  ACPI / video: update the skip case for acpi_video_device_in_dod()
  power / PM: Eliminate CONFIG_PM_RUNTIME
  NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / EC: Fix unexpected ec_remove_handlers() invocations
  Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
  tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
  PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
  mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
  PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
  ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  ACPI / PM: Do not disable wakeup GPEs that have not been enabled
  ACPI / utils: Drop error messages from acpi_evaluate_reference()
  ...
2014-12-18 20:28:33 -08:00
Linus Torvalds a7c180aa7e As the merge window is still open, and this code was not as complex
as I thought it might be. I'm pushing this in now.
 
 This will allow Thomas to debug his irq work for 3.20.
 
 This adds two new features:
 
 1) Allow traceopoints to be enabled right after mm_init(). By passing
 in the trace_event= kernel command line parameter, tracepoints can be
 enabled at boot up. For debugging things like the initialization of
 interrupts, it is needed to have tracepoints enabled very early. People
 have asked about this before and this has been on my todo list. As it
 can be helpful for Thomas to debug his upcoming 3.20 IRQ work, I'm
 pushing this now. This way he can add tracepoints into the IRQ set up
 and have users enable them when things go wrong.
 
 2) Have the tracepoints printed via printk() (the console) when they
 are triggered. If the irq code locks up or reboots the box, having the
 tracepoint output go into the kernel ring buffer is useless for
 debugging. But being able to add the tp_printk kernel command line
 option along with the trace_event= option will have these tracepoints
 printed as they occur, and that can be really useful for debugging
 early lock up or reboot problems.
 
 This code is not that intrusive and it passed all my tests. Thomas tried
 them out too and it works for his needs.
 
  Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUjv3kAAoJEEjnJuOKh9ldLNsIANAe5EmDCBw0WjR72n+G3qOH
 NC8calXfkjqHU0bv8Q3dRv20KH4MHOy6l4+EiV9/ovt71LOF3NEyUJ3HuShf9a8b
 sWcUhYbX3D1hViQe5sOzv9AWhBCFlKQGoNmQnydX9xa8ivRsBaTGJIGktWlHcwBE
 jF1i3fj3l3vRQSS8qZFXp3bzreunlGyPoSHcT6eWQeos+utj4sKwQWTLXTLQeM+6
 oQtFKRx7E5yX04qO1qFczS8qIEC6JH2C2jIRYEKUGepaELlnGkb8O7jQV/RaLF4/
 6P8VhZFG9YLS7fn7vWu0SnAN+Zwz5LzgjXAZt0FhGtIhLc18Oj8ouHH1UORsdQM=
 =Z4Un
 -----END PGP SIGNATURE-----

Merge tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "As the merge window is still open, and this code was not as complex as
  I thought it might be.  I'm pushing this in now.

  This will allow Thomas to debug his irq work for 3.20.

  This adds two new features:

  1) Allow traceopoints to be enabled right after mm_init().

     By passing in the trace_event= kernel command line parameter,
     tracepoints can be enabled at boot up.  For debugging things like
     the initialization of interrupts, it is needed to have tracepoints
     enabled very early.  People have asked about this before and this
     has been on my todo list.  As it can be helpful for Thomas to debug
     his upcoming 3.20 IRQ work, I'm pushing this now.  This way he can
     add tracepoints into the IRQ set up and have users enable them when
     things go wrong.

  2) Have the tracepoints printed via printk() (the console) when they
     are triggered.

     If the irq code locks up or reboots the box, having the tracepoint
     output go into the kernel ring buffer is useless for debugging.
     But being able to add the tp_printk kernel command line option
     along with the trace_event= option will have these tracepoints
     printed as they occur, and that can be really useful for debugging
     early lock up or reboot problems.

  This code is not that intrusive and it passed all my tests.  Thomas
  tried them out too and it works for his needs.

   Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org"

* tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add tp_printk cmdline to have tracepoints go to printk()
  tracing: Move enabling tracepoints to just after rcu_init()
2014-12-16 12:53:59 -08:00
Steven Rostedt (Red Hat) 0daa230296 tracing: Add tp_printk cmdline to have tracepoints go to printk()
Add the kernel command line tp_printk option that will have tracepoints
that are active sent to printk() as well as to the trace buffer.

Passing "tp_printk" will activate this. To turn it off, the sysctl
/proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note,
this only works if the cmdline option is used. Echoing 1 into the sysctl
file without the cmdline option will have no affect.

Note, this is a dangerous option. Having high frequency tracepoints send
their data to printk() can possibly cause a live lock. This is another
reason why this is only active if the command line option is used.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:17:38 -05:00
Steven Rostedt (Red Hat) 5f893b2639 tracing: Move enabling tracepoints to just after rcu_init()
Enabling tracepoints at boot up can be very useful. The tracepoint
can be initialized right after RCU has been. There's no need to
wait for the early_initcall() to be called. That's too late for some
things that can use tracepoints for debugging. Move the logic to
enable tracepoints out of the initcalls and into init/main.c to
right after rcu_init().

This also allows trace_printk() to be used early too.

Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos
Link: http://lkml.kernel.org/r/20141214164104.307127356@goodmis.org

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15 10:16:50 -05:00
Linus Torvalds caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Rafael J. Wysocki 798bc6d8d5 tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so files that are
build conditionally if CONFIG_PM_RUNTIME is set may now be build
if CONFIG_PM is set.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in kernel/trace/Makefile
for this reason.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org.
2014-12-13 02:23:30 +01:00
Linus Torvalds a7cb7bb664 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree update from Jiri Kosina:
 "Usual stuff: documentation updates, printk() fixes, etc"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  intel_ips: fix a type in error message
  cpufreq: cpufreq-dt: Move newline to end of error message
  ps3rom: fix error return code
  treewide: fix typo in printk and Kconfig
  ARM: dts: bcm63138: change "interupts" to "interrupts"
  Replace mentions of "list_struct" to "list_head"
  kernel: trace: fix printk message
  scsi: mpt2sas: fix ioctl in comment
  zbud, zswap: change module author email
  clocksource: Fix 'clcoksource' typo in comment
  arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help
  gpio: msm-v1: make boolean argument more obvious
  usb: Fix typo in usb-serial-simple.c
  PCI: Fix comment typo 'COMFIG_PM_OPS'
  powerpc: Fix comment typo 'CONIFG_8xx'
  powerpc: Fix comment typos 'CONFiG_ALTIVEC'
  clk: st: Spelling s/stucture/structure/
  isci: Spelling s/stucture/structure/
  usb: gadget: zero: Spelling s/infrastucture/infrastructure/
  treewide: Fix company name in module descriptions
  ...
2014-12-12 10:08:06 -08:00
Linus Torvalds 350e4f4985 This code is a fork from the trace-3.19 pull as it needed the trace_seq
clean ups from that branch.
 
 This code solves the issue of performing stack dumps from NMI context.
 The issue is that printk() is not safe from NMI context as if the NMI
 were to trigger when a printk() was being performed, the NMI could
 deadlock from the printk() internal locks. This has been seen in practice.
 
 With lots of review from Petr Mladek, this code went through several
 iterations, and we feel that it is now at a point of quality to be
 accepted into mainline.
 
 Here's what is contained in this patch set:
 
  o Creates a "seq_buf" generic buffer utility that allows a descriptor
    to be passed around where functions can write their own "printk()"
    formatted strings into it. The generic version was pulled out of
    the trace_seq() code that was made specifically for tracing.
 
  o The seq_buf code was change to model the seq_file code. I have
    a patch (not included for 3.19) that converts the seq_file.c code
    over to use seq_buf.c like the trace_seq.c code does. This was done
    to make sure that seq_buf.c is compatible with seq_file.c. I may
    try to get that patch in for 3.20.
 
  o The seq_buf.c file was moved to lib/ to remove it from being dependent
    on CONFIG_TRACING.
 
  o The printk() was updated to allow for a per_cpu "override" of
    the internal calls. That is, instead of writing to the console, a call
    to printk() may do something else. This made it easier to allow the
    NMI to change what printk() does in order to call dump_stack() without
    needing to update that code as well.
 
  o Finally, the dump_stack from all CPUs via NMI code was converted to
    use the seq_buf code. The caller to trigger the NMI code would wait
    till all the NMIs finished, and then it would print the seq_buf
    data to the console safely from a non NMI context.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUhbrnAAoJEEjnJuOKh9ldsCoIAJ3sKIJ5B3jxJJTCHPAx/lZD
 GVbV1J1mu4kTAZuhJZOAxW8D6PZGZMyEjg0y6ScDEnBGcjAZ9gTiWCdakPktf9EX
 GfaPPqwiL9dZ18J9Qc6uR+7M1Ffpzzwbcc6lJrpoTcjRgkoH9wCiLS9ozFQyYzWb
 /7m5UbUM/PIk9WAjLYXPW6UUVtPTPT0RdEQKofMGTeah+vgqj4TXCOROdlxsXXWF
 77vqBvPd5TUPWFH9ftzJGDtZS8SroXVKCu3fZIqHgzAU0yqwVtH/JzDTy9u2UYhX
 GzDEPeAIdp6m6Uyc406VuIf1QW0gfBgmA0ir80vFoP27uFMM6j5HlF7azgQfx34=
 =YBgA
 -----END PGP SIGNATURE-----

Merge tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull nmi-safe seq_buf printk update from Steven Rostedt:
 "This code is a fork from the trace-3.19 pull as it needed the
  trace_seq clean ups from that branch.

  This code solves the issue of performing stack dumps from NMI context.
  The issue is that printk() is not safe from NMI context as if the NMI
  were to trigger when a printk() was being performed, the NMI could
  deadlock from the printk() internal locks.  This has been seen in
  practice.

  With lots of review from Petr Mladek, this code went through several
  iterations, and we feel that it is now at a point of quality to be
  accepted into mainline.

  Here's what is contained in this patch set:

   - Creates a "seq_buf" generic buffer utility that allows a descriptor
     to be passed around where functions can write their own "printk()"
     formatted strings into it.  The generic version was pulled out of
     the trace_seq() code that was made specifically for tracing.

   - The seq_buf code was change to model the seq_file code.  I have a
     patch (not included for 3.19) that converts the seq_file.c code
     over to use seq_buf.c like the trace_seq.c code does.  This was
     done to make sure that seq_buf.c is compatible with seq_file.c.  I
     may try to get that patch in for 3.20.

   - The seq_buf.c file was moved to lib/ to remove it from being
     dependent on CONFIG_TRACING.

   - The printk() was updated to allow for a per_cpu "override" of the
     internal calls.  That is, instead of writing to the console, a call
     to printk() may do something else.  This made it easier to allow
     the NMI to change what printk() does in order to call dump_stack()
     without needing to update that code as well.

   - Finally, the dump_stack from all CPUs via NMI code was converted to
     use the seq_buf code.  The caller to trigger the NMI code would
     wait till all the NMIs finished, and then it would print the
     seq_buf data to the console safely from a non NMI context

  One added bonus is that this code also makes the NMI dump stack work
  on PREEMPT_RT kernels.  As printk() includes sleeping locks on
  PREEMPT_RT, printk() only writes to console if the console does not
  use any rt_mutex converted spin locks.  Which a lot do"

* tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  x86/nmi: Fix use of unallocated cpumask_var_t
  printk/percpu: Define printk_func when printk is not defined
  x86/nmi: Perform a safe NMI stack trace on all CPUs
  printk: Add per_cpu printk func to allow printk to be diverted
  seq_buf: Move the seq_buf code to lib/
  seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
  tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
  tracing: Have seq_buf use full buffer
  seq_buf: Add seq_buf_can_fit() helper function
  tracing: Add paranoid size check in trace_printk_seq()
  tracing: Use trace_seq_used() and seq_buf_used() instead of len
  tracing: Clean up tracing_fill_pipe_page()
  seq_buf: Create seq_buf_used() to find out how much was written
  tracing: Add a seq_buf_clear() helper and clear len and readpos in init
  tracing: Convert seq_buf fields to be like seq_file fields
  tracing: Convert seq_buf_path() to be like seq_path()
  tracing: Create seq_buf layer in trace_seq
2014-12-10 20:35:41 -08:00
Linus Torvalds 1dd7dcb6ea There was a lot of clean ups and minor fixes. One of those clean ups was
to the trace_seq code. It also removed the return values to the
 trace_seq_*() functions and use trace_seq_has_overflowed() to see if
 the buffer filled up or not. This is similar to work being done to the
 seq_file code as well in another tree.
 
 Some of the other goodies include:
 
  o Added some "!" (NOT) logic to the tracing filter.
 
  o Fixed the frame pointer logic to the x86_64 mcount trampolines
 
  o Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
    That is, the ftrace trampoline can be dynamically allocated
    and be called directly by functions that only have a single hook
    to them.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJUhbLGAAoJEEjnJuOKh9ldRV4H/3NcLbgGB2iu96la1zdYE6pG
 Q7cDJMxXK80YIIL70h9G0IItcD4t62LMb72lfBnMGRj3msgFb3AgISW57EuI0Pxk
 xk24wuIPoTG2S7v9sc3SboNFwO8qbtIjxD2OBmqIUrGo2sZIiGjyj3gX7mCY3uzL
 WB2bUOSFz/22OgaANinR5EELHA3pZZCf54Vz1K9ndmtK0xp0j1a7xJShD6TrMdYv
 mZ3zH5ViIhW4A3mdcMceh6fy2JLQAiEKF0uPTvcMMz7NlVul0mxyL/+10P7AE/3R
 Ehw4fzmm4NDshPDtBOkKH0LsppgXzuItFuQUTpact3JlqTg++bV6onSsrkt1hlY=
 =Z7Cm
 -----END PGP SIGNATURE-----

Merge tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There was a lot of clean ups and minor fixes.  One of those clean ups
  was to the trace_seq code.  It also removed the return values to the
  trace_seq_*() functions and use trace_seq_has_overflowed() to see if
  the buffer filled up or not.  This is similar to work being done to
  the seq_file code as well in another tree.

  Some of the other goodies include:

   - Added some "!" (NOT) logic to the tracing filter.

   - Fixed the frame pointer logic to the x86_64 mcount trampolines

   - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems.
     That is, the ftrace trampoline can be dynamically allocated and be
     called directly by functions that only have a single hook to them"

* tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits)
  tracing: Truncated output is better than nothing
  tracing: Add additional marks to signal very large time deltas
  Documentation: describe trace_buf_size parameter more accurately
  tracing: Allow NOT to filter AND and OR clauses
  tracing: Add NOT to filtering logic
  ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter
  ftrace/x86: Get rid of ftrace_caller_setup
  ftrace/x86: Have save_mcount_regs macro also save stack frames if needed
  ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs
  ftrace/x86: Simplify save_mcount_regs on getting RIP
  ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter
  ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments
  ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file
  ftrace/x86: Have static tracing also use ftrace_caller_setup
  ftrace/x86: Have static function tracing always test for function graph
  kprobes: Add IPMODIFY flag to kprobe_ftrace_ops
  ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
  kprobes/ftrace: Recover original IP if pre_handler doesn't change it
  tracing/trivial: Fix typos and make an int into a bool
  tracing: Deletion of an unnecessary check before iput()
  ...
2014-12-10 19:58:13 -08:00
Arianna Avanzini 7eca210375 blktrace: don't let the sysfs interface remove trace from running list
Currently, blktrace can be started/stopped via its ioctl-based interface
(used by the userspace blktrace tool) or via its ftrace interface. The
function blk_trace_remove_queue(), called each time an "enable" tunable
of the ftrace interface transitions to zero, removes the trace from the
running list, even if no function from the sysfs interface adds it to
such a list. This leads to a null pointer dereference.  This commit
changes the blk_trace_remove_queue() function so that it does not remove
the blk_trace from the running list.

v2:
    - Now the patch removes the invocation of list_del() instead of
      adding an useless if branch, as suggested by Namhyung Kim.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 14:59:09 -07:00
Al Viro ba00410b81 Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
Dan Carpenter 3558a5ac50 tracing: Truncated output is better than nothing
The initial reason for this patch is that I noticed that:

	if (len > TRACE_BUF_SIZE)

is off by one.  In this code, if len == TRACE_BUF_SIZE, then it means we
have truncated the last character off the output string.  If we truncate
two or more characters then we exit without printing.

After some discussion, we decided that printing truncated data is better
than not printing at all so we should just use vscnprintf() and remove
the test entirely.  Also I have updated memcpy() to copy the NUL char
instead of setting the NUL in a separate step.

Link: http://lkml.kernel.org/r/20141127155752.GA21914@mwanda

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 17:10:14 -05:00
Byungchul Park 8e1e1df29d tracing: Add additional marks to signal very large time deltas
Currently, function graph tracer prints "!" or "+" just before
function execution time to signal a function overhead, depending
on the time. And some tracers tracing latency also print "!" or
"+" just after time to signal overhead, depending on the interval
between events. Even it is usually enough to do that, we sometimes
need to signal for bigger execution time than 100 micro seconds.

For example, I used function graph tracer to detect if there is
any case that exit_mm() takes too much time. I did following steps
in /sys/kernel/debug/tracing. It was easier to detect very large
excution time with patched kernel than with original kernel.

$ echo exit_mm > set_graph_function
$ echo function_graph > current_tracer
$ echo > trace
$ cat trace_pipe > $LOGFILE
 ... (do something and terminate logging)
$ grep "\\$" $LOGFILE
 3) $ 22082032 us |                      } /* kernel_map_pages */
 3) $ 22082040 us |                    } /* free_pages_prepare */
 3) $ 22082113 us |                  } /* free_hot_cold_page */
 3) $ 22083455 us |                } /* free_hot_cold_page_list */
 3) $ 22083895 us |              } /* release_pages */
 3) $ 22177873 us |            } /* free_pages_and_swap_cache */
 3) $ 22178929 us |          } /* unmap_single_vma */
 3) $ 22198885 us |        } /* unmap_vmas */
 3) $ 22206949 us |      } /* exit_mmap */
 3) $ 22207659 us |    } /* mmput */
 3) $ 22207793 us |  } /* exit_mm */

And then, it was easy to find out that a schedule-out occured by
sub_preempt_count() within kernel_map_pages().

To detect very large function exection time caused by either problematic
function implementation or scheduling issues, this patch can be useful.

Link: http://lkml.kernel.org/r/1416789259-24038-1-git-send-email-byungchul.park@lge.com

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 17:10:13 -05:00
Steven Rostedt (Red Hat) eabb8980a9 tracing: Allow NOT to filter AND and OR clauses
Add support to allow not "!" for and (&&) and (||). That is:

 !(field1 == X && field2 == Y)

Where the value of the full clause will be notted.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 10:00:27 -05:00
Steven Rostedt (Red Hat) e12c09cf30 tracing: Add NOT to filtering logic
Ted noticed that he could not filter on an event for a bit being cleared.
That's because the filtering logic only tests event fields with a limited
number of comparisons which, for bit logic, only include "&", which can
test if a bit is set, but there's no good way to see if a bit is clear.

This adds a way to do: !(field & 2048)

Which returns true if the bit is not set, and false otherwise.

Note, currently !(field1 == 10 && field2 == 15) is not supported.
That is, the 'not' only works for direct comparisons, not for the
AND and OR logic.

Link: http://lkml.kernel.org/r/20141202021912.GA29096@thunk.org
Link: http://lkml.kernel.org/r/20141202120430.71979060@gandalf.local.home

Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Suggested-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-03 10:00:13 -05:00
Masami Hiramatsu f8b8be8a31 ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict
Introduce FTRACE_OPS_FL_IPMODIFY to avoid conflict among
ftrace users who may modify regs->ip to change the execution
path. If two or more users modify the regs->ip on the same
function entry, one of them will be broken. So they must add
IPMODIFY flag and make sure that ftrace_set_filter_ip() succeeds.

Note that ftrace doesn't allow ftrace_ops which has IPMODIFY
flag to have notrace hash, and the ftrace_ops must have a
filter hash (so that the ftrace_ops can hook only specific
entries), because it strongly depends on the address and
must be allowed for only few selected functions.

Link: http://lkml.kernel.org/r/20141121102516.11844.27829.stgit@localhost.localdomain

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ fixed up some of the comments ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-21 14:42:10 -05:00
Steven Rostedt (Red Hat) 0af26492d5 tracing/trivial: Fix typos and make an int into a bool
Fix up a few typos in comments and convert an int into a bool in
update_traceon_count().

Link: http://lkml.kernel.org/r/546DD445.5080108@hitachi.com

Suggested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-20 10:05:36 -05:00
Jiri Kosina a02001086b Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
2014-11-20 14:42:02 +01:00
Frans Klaver eff264efee kernel: trace: fix printk message
s,produciton,production

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-11-20 14:29:19 +01:00
Steven Rostedt (Red Hat) 8d58e99af5 seq_buf: Move the seq_buf code to lib/
The seq_buf functions are rather useful outside of tracing. Instead
of having it be dependent on CONFIG_TRACING, move the code into lib/
and allow other users to have access to it even when tracing is not
configured.

The seq_buf utility is similar to the seq_file utility, but instead of
writing sending data back up to userland, it writes it into a buffer
defined at seq_buf_init(). This allows us to send a descriptor around
that writes printf() formatted strings into it that can be retrieved
later.

It is currently used by the tracing facility for such things like trace
events to convert its binary saved data in the ring buffer into an
ASCII human readable context to be displayed in /sys/kernel/debug/trace.

It can also be used for doing NMI prints safely from NMI context into
the seq_buf and retrieved later and dumped to printk() safely. Doing
printk() from an NMI context is dangerous because an NMI can preempt
a current printk() and deadlock on it.

Link: http://lkml.kernel.org/p/20140619213952.058255809@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:20 -05:00
Steven Rostedt (Red Hat) 2448913ed2 seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
The function bstr_printf() from lib/vsprnintf.c is only available if
CONFIG_BINARY_PRINTF is defined. This is due to the only user currently
being the tracing infrastructure, which needs to select this config
when tracing is configured. Until there is another user of the binary
printf formats, this will continue to be the case.

Since seq_buf.c is now lives in lib/ and is compiled even without
tracing, it must encompass its use of bstr_printf() which is used
by seq_buf_printf(). This too is only used by the tracing infrastructure
and is still encapsulated by the CONFIG_BINARY_PRINTF.

Link: http://lkml.kernel.org/r/20141104160222.969013383@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:19 -05:00
Steven Rostedt (Red Hat) 01cb06a4c2 tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that
are used by seq_buf_path(). This makes the code similar to the
seq_file: seq_path() function, and will help to be able to consolidate
the functions between seq_file and trace_seq.

Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:18 -05:00
Steven Rostedt (Red Hat) 8cd709ae76 tracing: Have seq_buf use full buffer
Currently seq_buf is full when all but one byte of the buffer is
filled. Change it so that the seq_buf is full when all of the
buffer is filled.

Some of the functions would fill the buffer completely and report
everything was fine. This was inconsistent with the max of size - 1.
Changing this to be max of size makes all functions consistent.

Link: http://lkml.kernel.org/r/20141104160222.502133196@goodmis.org
Link: http://lkml.kernel.org/r/20141114011412.811957882@goodmis.org

Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:17 -05:00
Steven Rostedt (Red Hat) 9b77215382 seq_buf: Add seq_buf_can_fit() helper function
Add a seq_buf_can_fit() helper function that removes the possible mistakes
of comparing the seq_buf length plus added data compared to the size of
the buffer.

Link: http://lkml.kernel.org/r/20141118164025.GL23958@pathway.suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:17 -05:00
Steven Rostedt (Red Hat) 820b75f63d tracing: Add paranoid size check in trace_printk_seq()
To be really paranoid about writing out of bound data in
trace_printk_seq(), add another check of len compared to size.

Link: http://lkml.kernel.org/r/20141119144004.GB2332@dhcp128.suse.cz

Suggested-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 22:01:16 -05:00