Commit Graph

9038 Commits

Author SHA1 Message Date
Andi Kleen a5b9e2c106 kfifo: add kfifo_out_peek
In some upcoming code it's useful to peek into a FIFO without permanentely
removing data.  This patch implements a new kfifo_out_peek() to do this.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Walls <awalls@radix.net>
Cc: Vikram Dhillon <dhillonv10@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:38 -08:00
Andi Kleen 64ce1037c5 kfifo: sanitize *_user error handling
Right now for kfifo_*_user it's not easily possible to distingush between
a user copy failing and the FIFO not containing enough data.  The problem
is that both conditions are multiplexed into the same return code.

Avoid this by moving the "copy length" into a separate output parameter
and only return 0/-EFAULT in the main return value.

I didn't fully adapt the weird "record" variants, those seem
to be unused anyways and were rather messy (should they be just removed?)

I would appreciate some double checking if I did all the conversions
correctly.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Walls <awalls@radix.net>
Cc: Vikram Dhillon <dhillonv10@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:38 -08:00
Andi Kleen 8ecc295153 kfifo: use void * pointers for user buffers
The pointers to user buffers are currently unsigned char *, which requires
a lot of casting in the caller for any non-char typed buffers.  Use void *
instead.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andy Walls <awalls@radix.net>
Cc: Vikram Dhillon <dhillonv10@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:38 -08:00
Li Zefan d1303dd1d6 tracing/filters: Add comment for match callbacks
We should be clear on 2 things:

- the length parameter of a match callback includes
  tailing '\0'.

- the string to be searched might not be NULL-terminated.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8770.7000608@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:14 -05:00
Li Zefan 16da27a8bc tracing/filters: Fix MATCH_FULL filter matching for PTR_STRING
MATCH_FULL matching for PTR_STRING is not working correctly:

  # echo 'func == vt' > events/bkl/lock_kernel/filter
  # echo 1 > events/bkl/lock_kernel/enable
  ...
  # cat trace
   Xorg-1484  [000]  1973.392586: lock_kernel: ... func=vt_ioctl()
    gpm-1402  [001]  1974.027740: lock_kernel: ... func=vt_ioctl()

We should pass to regex.match(..., len) the length (including '\0')
of the source string instead of the length of the pattern string.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8763.5070707@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:12 -05:00
Li Zefan b2af211f28 tracing/filters: Fix MATCH_MIDDLE_ONLY filter matching
The @str might not be NULL-terminated if it's of type
DYN_STRING or STATIC_STRING, so we should use strnstr()
instead of strstr().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8753.2000102@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:11 -05:00
Li Zefan a3291c14ec tracing/filters: Fix MATCH_END_ONLY filter matching
For '*foo' pattern, we should allow any string ending with
'foo', but event filtering incorrectly disallows strings
like bar_foo_foo:

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8735.6070604@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:07 -05:00
Li Zefan 285caad415 tracing/filters: Fix MATCH_FRONT_ONLY filter matching
MATCH_FRONT_ONLY actually is a full matching:

  # ./perf record -R -f -a -e lock:lock_acquire \
	--filter 'name ~rcu_*' sleep 1
  # ./perf trace
  (no output)

We should pass the length of the pattern string to strncmp().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8721.5090301@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:05 -05:00
Li Zefan 751e9983ee ftrace: Fix MATCH_END_ONLY function filter
For '*foo' pattern, we should allow any string ending with
'foo', but ftrace filter incorrectly disallows strings
like bar_foo_foo:

  # echo '*io' > set_ftrace_filter
  # cat set_ftrace_filter | grep 'req_bio_endio'
  # cat available_filter_functions | grep 'req_bio_endio'
  req_bio_endio

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E870E.6060607@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14 22:38:03 -05:00
KOSAKI Motohiro 7485d0d375 futexes: Remove rw parameter from get_futex_key()
Currently, futexes have two problem:

A) The current futex code doesn't handle private file mappings properly.

get_futex_key() uses PageAnon() to distinguish file and
anon, which can cause the following bad scenario:

  1) thread-A call futex(private-mapping, FUTEX_WAIT), it
     sleeps on file mapping object.
  2) thread-B writes a variable and it makes it cow.
  3) thread-B calls futex(private-mapping, FUTEX_WAKE), it
     wakes up blocked thread on the anonymous page. (but it's nothing)

B) Current futex code doesn't handle zero page properly.

Read mode get_user_pages() can return zero page, but current
futex code doesn't handle it at all. Then, zero page makes
infinite loop internally.

The solution is to use write mode get_user_page() always for
page lookup. It prevents the lookup of both file page of private
mappings and zero page.

Performance concerns:

Probaly very little, because glibc always initialize variables
for futex before to call futex(). It means glibc users never see
the overhead of this patch.

Compatibility concerns:

This patch has few compatibility issues. After this patch,
FUTEX_WAIT require writable access to futex variables (read-only
mappings makes EFAULT). But practically it's not a problem,
glibc always initalizes variables for futexes explicitly - nobody
uses read-only mappings.

Reported-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Darren Hart <dvhltc@us.ibm.com>
Cc: <stable@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Ulrich Drepper <drepper@gmail.com>
LKML-Reference: <20100105162633.45A2.A69D9226@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-13 09:17:36 +01:00
Andi Kleen b45c6e76bc kernel/signal.c: fix kernel information leak with print-fatal-signals=1
When print-fatal-signals is enabled it's possible to dump any memory
reachable by the kernel to the log by simply jumping to that address from
user space.

Or crash the system if there's some hardware with read side effects.

The fatal signals handler will dump 16 bytes at the execution address,
which is fully controlled by ring 3.

In addition when something jumps to a unmapped address there will be up to
16 additional useless page faults, which might be potentially slow (and at
least is not very efficient)

Fortunately this option is off by default and only there on i386.

But fix it by checking for kernel addresses and also stopping when there's
a page fault.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11 09:34:05 -08:00
Dave Anderson bd4f490a07 cgroups: fix 2.6.32 regression causing BUG_ON() in cgroup_diput()
The LTP cgroup test suite generates a "kernel BUG at kernel/cgroup.c:790!"
here in cgroup_diput():

                 /*
                  * if we're getting rid of the cgroup, refcount should ensure
                  * that there are no pidlists left.
                  */
                 BUG_ON(!list_empty(&cgrp->pidlists));

The cgroup pidlist rework in 2.6.32 generates the BUG_ON, which is caused
when pidlist_array_load() calls cgroup_pidlist_find():

(1) if a matching cgroup_pidlist is found, it down_write's the mutex of the
     pre-existing cgroup_pidlist, and increments its use_count.
(2) if no matching cgroup_pidlist is found, then a new one is allocated, it
     down_write's its mutex, and the use_count is set to 0.
(3) the matching, or new, cgroup_pidlist gets returned back to pidlist_array_load(),
     which increments its use_count -- regardless whether new or pre-existing --
     and up_write's the mutex.

So if a matching list is ever encountered by cgroup_pidlist_find() during
the life of a cgroup directory, it results in an inflated use_count value,
preventing it from ever getting released by cgroup_release_pid_array().
Then if the directory is subsequently removed, cgroup_diput() hits the
BUG_ON() when it finds that the directory's cgroup is still populated with
a pidlist.

The patch simply removes the use_count increment when a matching pidlist
is found by cgroup_pidlist_find(), because it gets bumped by the calling
pidlist_array_load() function while still protected by the list's mutex.

Signed-off-by: Dave Anderson <anderson@redhat.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Ben Blum <bblum@andrew.cmu.edu>
Cc: Paul Menage <menage@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11 09:34:05 -08:00
Masami Hiramatsu 8767ba2796 kmod: fix resource leak in call_usermodehelper_pipe()
Fix resource (write-pipe file) leak in call_usermodehelper_pipe().

When call_usermodehelper_exec() fails, write-pipe file is opened and
call_usermodehelper_pipe() just returns an error.  Since it is hard for
caller to determine whether the error occured when opening the pipe or
executing the helper, the caller cannot close the pipe by themselves.

I've found this resoruce leak when testing coredump.  You can check how
the resource leaks as below;

$ echo "|nocommand" > /proc/sys/kernel/core_pattern
$ ulimit -c unlimited
$ while [ 1 ]; do ./segv; done &> /dev/null &
$ cat /proc/meminfo (<- repeat it)

where segv.c is;
//-----
int main () {
        char *p = 0;
        *p = 1;
}
//-----

This patch closes write-pipe file if call_usermodehelper_exec() failed.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11 09:34:04 -08:00
Steven Rostedt 0e1ff5d72a ring-buffer: Add rb_list_head() wrapper around new reader page next field
If the very unlikely case happens where the writer moves the head by one
between where the head page is read and where the new reader page
is assigned _and_ the writer then writes and wraps the entire ring buffer
so that the head page is back to what was originally read as the head page,
the page to be swapped will have a corrupted next pointer.

Simple solution is to wrap the assignment of the next pointer with a
rb_list_head().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 20:40:44 -05:00
David Sharp 5ded3dc6a3 ring-buffer: Wrap a list.next reference with rb_list_head()
This reference at the end of rb_get_reader_page() was causing off-by-one
writes to the prev pointer of the page after the reader page when that
page is the head page, and therefore the reader page has the RB_PAGE_HEAD
flag in its list.next pointer. This eventually results in a GPF in a
subsequent call to rb_set_head_page() (usually from rb_get_reader_page())
when that prev pointer is dereferenced. The dereferenced register would
characteristically have an address that appears shifted left by one byte
(eg, ffxxxxxxxxxxxxyy instead of ffffxxxxxxxxxxxx) due to being written at
an address one byte too high.

Signed-off-by: David Sharp <dhsharp@google.com>
LKML-Reference: <1262826727-9090-1-git-send-email-dhsharp@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06 20:38:25 -05:00
Ben Hutchings 10b465aaf9 modules: Skip empty sections when exporting section notes
Commit 35dead4 "modules: don't export section names of empty sections
via sysfs" changed the set of sections that have attributes, but did
not change the iteration over these attributes in add_notes_attrs().
This can lead to add_notes_attrs() creating attributes with the wrong
names or with null name pointers.

Introduce a sect_empty() function and use it in both add_sect_attrs()
and add_notes_attrs().

Reported-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-06 01:11:29 -08:00
Linus Torvalds 952363c90c Merge branch 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Fix NULL deref in inheritance code
  perf: Pass appropriate frame pointer to dump_trace()
2009-12-31 11:56:24 -08:00
Linus Torvalds 9d6e323c68 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf kmem: Fix statistics typo
  kprobes: Fix distinct type warning
  perf: Rename perf_event_hw_event in design document
  perf tools: Add missing header files to LIB_H Makefile variable
  perf record: We should fork only if a program was specified to run
  perf diff: Fix usage array, it must end with a NULL entry
2009-12-31 11:52:24 -08:00
Linus Torvalds b21c070403 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Fix sign fields in ftrace_define_fields_##call()
  tracing/syscalls: Fix typo in SYSCALL_DEFINE0
  tracing/kprobe: Show sign of fields in trace_kprobe format files
  ksym_tracer: Remove trace_stat
  ksym_tracer: Fix race when incrementing count
  ksym_tracer: Fix to allow writing newline to ksym_trace_filter
  ksym_tracer: Fix to make the tracer work
  tracing: Kconfig spelling fixes and cleanups
  tracing: Fix setting tracer specific options
  Documentation: Update ftrace-design.txt
  Documentation: Update tracepoint-analysis.txt
  Documentation: Update mmiotrace.txt
2009-12-31 11:52:01 -08:00
KOSAKI Motohiro 0f4bd46ec2 kmsg_dump: Dump on crash_kexec as well
crash_kexec gets called before kmsg_dump(KMSG_DUMP_OOPS) if
panic_on_oops is set, so the kernel log buffer is not stored
for this case.

This patch adds a KMSG_DUMP_KEXEC dump type which gets called
when crash_kexec() is invoked. To avoid getting double dumps,
the old KMSG_DUMP_PANIC is moved below crash_kexec(). The
mtdoops driver is modified to handle KMSG_DUMP_KEXEC in the
same way as a panic.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-12-31 19:45:04 +00:00
Peter Zijlstra 05cbaa2853 perf: Fix NULL deref in inheritance code
Liming found a NULL deref when a task has a perf context but no
counters  when it forks.

This can occur in two cases, a race during construction where
the fork hits after installing the context but before the first
counter gets inserted, or more reproducably, a fork after the
last counter is closed (which leaves the context around).

Reported-by: Wang Liming <liming.wang@windriver.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
CC: <stable@kernel.org>
LKML-Reference: <1262185684.7135.222.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-31 13:11:31 +01:00
Lai Jiangshan fb7ae981cb tracing: Fix sign fields in ftrace_define_fields_##call()
Add is_signed_type() call to trace_define_field() in ftrace macros.

The code previously just passed in 0 (false), disregarding whether
or not the field was actually a signed type.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D3A.6020007@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-30 10:27:06 -05:00
Lai Jiangshan 79b4082108 tracing/kprobe: Show sign of fields in trace_kprobe format files
The format files of trace_kprobe do not show the sign of the fields.
The other format files show the field signed type of the fields and
this patch makes the trace_kprobe formats consistent with the others.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4B273D27.5040009@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-30 10:27:03 -05:00
Li Zefan 53ab668064 ksym_tracer: Remove trace_stat
trace_stat is problematic. Don't use it, use seqfile instead.

This fixes a race that reading the stat file is not protected by
any lock, which can lead to use after free.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B3AF203.40200@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30 07:50:50 +01:00
Li Zefan e6d9491bf8 ksym_tracer: Fix race when incrementing count
We are under rcu read section but not holding the write lock, so
count++ is not atomic. Use atomic64_t instead.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B3AF1EC.9010608@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30 07:50:49 +01:00
Li Zefan 3d13ec2efd ksym_tracer: Fix to allow writing newline to ksym_trace_filter
It used to work, but now doesn't:

 # echo > ksym_filter
 bash: echo: write error: Invalid argument

It's caused by d954fbf0ff
("tracing: Fix wrong usage of strstrip in trace_ksyms").

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B3AF1D7.5040400@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30 07:50:49 +01:00
Li Zefan 88f7a890d7 ksym_tracer: Fix to make the tracer work
ksym tracer doesn't work:

 # echo tasklist_lock:rw- > ksym_trace_filter
 -bash: echo: write error: No such device

It's because we pass to perf_event_create_kernel_counter()
a cpu number which is not present.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B3AF19E.1010201@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-30 07:50:47 +01:00
Randy Dunlap 40892367bc tracing: Kconfig spelling fixes and cleanups
Fix filename reference (ftrace-implementation.txt ->
ftrace-design.txt).

Fix spelling, punctuation, grammar.

Fix help text indentation and line lengths to reduce need for
horizontal scrolling or larger window sizes.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091221120117.3fb49cdc.randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-28 10:37:54 +01:00
Heiko Carstens c2ef6661ce kprobes: Fix distinct type warning
Every time I see this:

 kernel/kprobes.c: In function 'register_kretprobe':
 kernel/kprobes.c:1038: warning: comparison of distinct pointer types lacks a cast

I'm wondering if something changed in common code and we need to
do something for s390. Apparently that's not the case.
Let's get rid of this annoying warning.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <20091221120224.GA4471@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-28 10:25:31 +01:00
Linus Torvalds 0b5e2588d8 Merge branch 'sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc-2.6
* 'sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc-2.6:
  SYSCTL: Add a mutex to the page_alloc zone order sysctl
  SYSCTL: Print binary sysctl warnings (nearly) only once
2009-12-24 13:01:29 -08:00
Andi Kleen 4440095c82 SYSCTL: Print binary sysctl warnings (nearly) only once
When printing legacy sysctls print the warning message
for each of them only once.  This way there is a guarantee
the syslog won't be flooded for any sane program.

The original attempt at this made the tables non const and stored
the flag inline.

Linus suggested using a separate hash table for this, this is based on a
code snippet from him.

The hash implies this is not exact and can sometimes not print a
new sysctl due to a hash collision, but in practice this should not
be a problem

I used a FNV32 hash over the binary string with a 32byte bitmap. This
gives relatively little collisions when all the predefined binary sysctls
are hashed:

size 256
bucket
length      number
0:          [25]
1:          [67]
2:          [88]
3:          [47]
4:          [22]
5:          [6]
6:          [1]

The worst case is a single collision of 6 hash values.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-23 21:00:20 +01:00
Linus Torvalds 6432ed648a Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Revert 738d2be, simplify set_task_cpu()
2009-12-23 09:12:57 -08:00
Peter Zijlstra 0c69774e6c sched: Revert 738d2be, simplify set_task_cpu()
Effectively reverts 738d2be430.

As demonstrated by Eric, we really need to call __set_task_cpu()
early in the fork() path to properly initialize the various task
state -- specifically the cgroup state through set_task_rq().

[ we could probably fix this by explicitly calling
  __set_task_cpu() from   sched_fork(), but lets try that for the
  next cycle and simply revert to the old behaviour for now. ]

Reported-by: Eric Paris <eparis@redhat.com>
Tested-by: Eric Paris <eparis@redhat.com>,
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: efault@gmx.de
LKML-Reference: <1261492999.4937.36.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-23 10:04:10 +01:00
Linus Torvalds fe35d4a028 Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  jfs: Fix 32bit build warning
  Remove obsolete comment in fs.h
  Sanitize f_flags helpers
  Fix f_flags/f_mode in case of lookup_instantiate_filp() from open(pathname, 3)
  anonfd: Allow making anon files read-only
  fs/compat_ioctl.c: fix build error when !BLOCK
  pohmelfs needs I_LOCK
  alloc_file(): simplify handling of mnt_clone_write() errors
2009-12-22 14:20:48 -08:00
Stefani Seibold 86d4880313 kfifo: add record handling functions
Add kfifo_in_rec() - puts some record data into the FIFO
 Add kfifo_out_rec() - gets some record data from the FIFO
 Add kfifo_from_user_rec() - puts some data from user space into the FIFO
 Add kfifo_to_user_rec() - gets data from the FIFO and write it to user space
 Add kfifo_peek_rec() - gets the size of the next FIFO record field
 Add kfifo_skip_rec() - skip the next fifo out record
 Add kfifo_avail_rec() - determinate the number of bytes available in a record FIFO

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold a121f24acc kfifo: add kfifo_skip, kfifo_from_user and kfifo_to_user
Add kfifo_reset_out() for save lockless discard the fifo output
 Add kfifo_skip() to skip a number of output bytes
 Add kfifo_from_user() to copy user space data into the fifo
 Add kfifo_to_user() to copy fifo data to user space

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold 7acd72eb85 kfifo: rename kfifo_put... into kfifo_in... and kfifo_get... into kfifo_out...
rename kfifo_put...  into kfifo_in...  to prevent miss use of old non in
kernel-tree drivers

ditto for kfifo_get...  -> kfifo_out...

Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc
annotations more readable.

Add mini "howto porting to the new API" in kfifo.h

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold e64c026dd0 kfifo: cleanup namespace
change name of __kfifo_* functions to kfifo_*, because the prefix __kfifo
should be reserved for internal functions only.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold c1e13f2567 kfifo: move out spinlock
Move the pointer to the spinlock out of struct kfifo.  Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold 4546548789 kfifo: move struct kfifo in place
This is a new generic kernel FIFO implementation.

The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.

I think this are the reasons why kfifo is not in use:

 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo

So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:

 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!

This patch:

Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:55 -08:00
Linus Torvalds 83f57a11d8 Revert "time: Remove xtime_cache"
This reverts commit 7bc7d63745, as
requested by John Stultz. Quoting John:

 "Petr Titěra reported an issue where he saw odd atime regressions with
  2.6.33 where there were a full second worth of nanoseconds in the
  nanoseconds field.

  He also reviewed the time code and narrowed down the problem: unhandled
  overflow of the nanosecond field caused by rounding up the
  sub-nanosecond accumulated time.

  Details:

   * At the end of update_wall_time(), we currently round up the
  sub-nanosecond portion of accumulated time when storing it into xtime.
  This was added to avoid time inconsistencies caused when the
  sub-nanosecond portion was truncated when storing into xtime.
  Unfortunately we don't handle the possible second overflow caused by
  that rounding.

   * Previously the xtime_cache code hid this overflow by normalizing the
  xtime value when storing into the xtime_cache.

   * We could try to handle the second overflow after the rounding up, but
  since this affects the timekeeping's internal state, this would further
  complicate the next accumulation cycle, causing small errors in ntp
  steering. As much as I'd like to get rid of it, the xtime_cache code is
  known to work.

   * The correct fix is really to include the sub-nanosecond portion in the
  timekeeping accessor function, so we don't need to round up at during
  accumulation. This would greatly simplify the accumulation code.
  Unfortunately, we can't do this safely until the last three
  non-GENERIC_TIME arches (sparc32, arm, cris) are converted  (those
  patches are in -mm) and we kill off the spots where arches set xtime
  directly. This is all 2.6.34 material, so I think reverting the
  xtime_cache change is the best approach for now.

  Many thanks to Petr for both reporting and finding the issue!"

Reported-by: Petr Titěra <P.Titera@century.cz>
Requested-by: john stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:10:37 -08:00
Al Viro 5300990c03 Sanitize f_flags helpers
* pull ACC_MODE to fs.h; we have several copies all over the place
* nightmarish expression calculating f_mode by f_flags deserves a helper
too (OPEN_FMODE(flags))

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-22 12:27:34 -05:00
Roland Dreier 628ff7c1d8 anonfd: Allow making anon files read-only
It seems a couple places such as arch/ia64/kernel/perfmon.c and
drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile()
instead of a private pseudo-fs + alloc_file(), if only there were a way
to get a read-only file.  So provide this by having anon_inode_getfile()
create a read-only file if we pass O_RDONLY in flags.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-22 12:27:34 -05:00
Steven Rostedt c757bea93b tracing: Fix setting tracer specific options
The function __set_tracer_option() takes as its last parameter a
"neg" value. If set it should negate the value of the option.

The trace_options_write() passed the value written to the file
which is what the new value needs to be set as. But since this
is not the negative, it never sets the value.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-21 22:35:16 -05:00
Dominik Brodowski 0e2c8b8f55 resources: fix call to alignf() in allocate_resource()
The second parameter to alignf() in allocate_resource() must
reflect what new resource is attempted to be allocated, else
functions like pcibios_align_resource() (at least on x86) or
pcmcia_align() can't work correctly.

Commit 1e5ad96790 broke this by
setting the "new" resource until we're about to return success.
To keep the resource untouched when allocate_resource() fails,
a "tmp" resource is introduced.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-21 10:42:29 -08:00
Peter Zijlstra 70f1120527 sched: Fix hotplug hang
The hot-unplug kstopmachine usage does a wakeup after
deactivating the cpu, hence we cannot use cpu_active()
here but must rely on the good olde online.

Reported-by: Sachin Sant <sachinp@in.ibm.com>
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <1261326987.4314.24.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 23:31:23 +01:00
Peter Zijlstra 3df0fc5b2e sched: Restore printk sanity
Revert the braindead pr_* crap. (Commit 663997d "sched: Use
pr_fmt() and pr_<level>()")

It's dumb and causes stupid "sched: " strings all over the place.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Mike Galbraith <efault@gmx.de>
Cc: Joe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1261315437.4314.6.camel@laptop>
[ i dont mind the pr_*() patterns that much - but Peter dislikes them with a vengence. ]
[ - v2: remove spurious diffstat from changelog :-/ ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-20 19:05:02 +01:00
Linus Torvalds eca9dfcd00 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf session: Make events_stats u64 to avoid overflow on 32-bit arches
  hw-breakpoints: Fix hardware breakpoints -> perf events dependency
  perf events: Dont report side-band events on each cpu for per-task-per-cpu events
  perf events, x86/stacktrace: Fix performance/softlockup by providing a special frame pointer-only stack walker
  perf events, x86/stacktrace: Make stack walking optional
  perf events: Remove unused perf_counter.h header file
  perf probe: Check new event name
  kprobe-tracer: Check new event/group name
  perf probe: Check whether debugfs path is correct
  perf probe: Fix libdwarf include path for Debian
2009-12-19 09:48:42 -08:00
Linus Torvalds aac3d39693 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits)
  sched: Fix broken assertion
  sched: Assert task state bits at build time
  sched: Update task_state_arraypwith new states
  sched: Add missing state chars to TASK_STATE_TO_CHAR_STR
  sched: Move TASK_STATE_TO_CHAR_STR near the TASK_state bits
  sched: Teach might_sleep() about preemptible RCU
  sched: Make warning less noisy
  sched: Simplify set_task_cpu()
  sched: Remove the cfs_rq dependency from set_task_cpu()
  sched: Add pre and post wakeup hooks
  sched: Move kthread_bind() back to kthread.c
  sched: Fix select_task_rq() vs hotplug issues
  sched: Fix sched_exec() balancing
  sched: Ensure set_task_cpu() is never called on blocked tasks
  sched: Use TASK_WAKING for fork wakups
  sched: Select_task_rq_fair() must honour SD_LOAD_BALANCE
  sched: Fix task_hot() test order
  sched: Fix set_cpu_active() in cpu_down()
  sched: Mark boot-cpu active before smp_init()
  sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
  ...
2009-12-19 09:47:49 -08:00
Linus Torvalds 10e5453ffa Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sys: Fix missing rcu protection for __task_cred() access
  signals: Fix more rcu assumptions
  signal: Fix racy access to __task_cred in kill_pid_info_as_uid()
2009-12-19 09:47:34 -08:00
Linus Torvalds 3cd312c3e8 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  timers: Remove duplicate setting of new_base in __mod_timer()
  clockevents: Prevent clockevent_devices list corruption on cpu hotplug
2009-12-19 09:47:18 -08:00
Al Viro b4c30aad39 fix more leaks in audit_tree.c tag_chunk()
Several leaks in audit_tree didn't get caught by commit
318b6d3d7d, including the leak on normal
exit in case of multiple rules refering to the same chunk.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-19 09:27:43 -08:00
Al Viro 6f5d511489 fix braindamage in audit_tree.c untag_chunk()
... aka "Al had badly fscked up when writing that thing and nobody
noticed until Eric had fixed leaks that used to mask the breakage".

The function essentially creates a copy of old array sans one element
and replaces the references to elements of original (they are on cyclic
lists) with those to corresponding elements of new one.  After that the
old one is fair game for freeing.

First of all, there's a dumb braino: when we get to list_replace_init we
use indices for wrong arrays - position in new one with the old array
and vice versa.

Another bug is more subtle - termination condition is wrong if the
element to be excluded happens to be the last one.  We shouldn't go
until we fill the new array, we should go until we'd finished the old
one.  Otherwise the element we are trying to kill will remain on the
cyclic lists...

That crap used to be masked by several leaks, so it was not quite
trivial to hit.  Eric had fixed some of those leaks a while ago and the
shit had hit the fan...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-19 09:27:43 -08:00
Linus Torvalds 55db493b65 Merge branch 'cpumask-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'cpumask-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  cpumask: rename tsk_cpumask to tsk_cpus_allowed
  cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt
  cpumask: avoid dereferencing struct cpumask
  cpumask: convert drivers/idle/i7300_idle.c to cpumask_var_t
  cpumask: use modern cpumask style in drivers/scsi/fcoe/fcoe.c
  cpumask: avoid deprecated function in mm/slab.c
  cpumask: use cpu_online in kernel/perf_event.c
2009-12-17 17:00:20 -08:00
Linus Torvalds efc8e7f4c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  Keys: KEYCTL_SESSION_TO_PARENT needs TIF_NOTIFY_RESUME architecture support
  NOMMU: Optimise away the {dac_,}mmap_min_addr tests
  security/min_addr.c: make init_mmap_min_addr() static
  keys: PTR_ERR return of wrong pointer in keyctl_get_security()
2009-12-17 16:58:26 -08:00
Linus Torvalds dcc7cd0112 Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6
* 'kmemleak' of git://linux-arm.org/linux-2.6:
  kmemleak: fix kconfig for crc32 build error
  kmemleak: Reduce the false positives by checking for modified objects
  kmemleak: Show the age of an unreferenced object
  kmemleak: Release the object lock before calling put_object()
  kmemleak: Scan the _ftrace_events section in modules
  kmemleak: Simplify the kmemleak_scan_area() function prototype
  kmemleak: Do not use off-slab management with SLAB_NOLEAKTRACE
2009-12-17 16:00:19 -08:00
Randy Dunlap 6485536bcf printk: fix new kernel-doc warnings
Fix kernel-doc warnings in printk.c:

Warning(kernel/printk.c:1422): No description found for parameter 'dumper'
Warning(kernel/printk.c:1422): Excess function parameter 'dump' description in 'kmsg_dump_register'
Warning(kernel/printk.c:1451): No description found for parameter 'dumper'
Warning(kernel/printk.c:1451): Excess function parameter 'dump' description in 'kmsg_dump_unregister'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17 15:45:32 -08:00
Oleg Nesterov 9cd80bbb07 do_wait() optimization: do not place sub-threads on task_struct->children list
Thanks to Roland who pointed out de_thread() issues.

Currently we add sub-threads to ->real_parent->children list.  This buys
nothing but slows down do_wait().

With this patch ->children contains only main threads (group leaders).
The only complication is that forget_original_parent() should iterate over
sub-threads by hand, and de_thread() needs another list_replace() when it
changes ->group_leader.

Henceforth do_wait_thread() can never see task_detached() && !EXIT_DEAD
tasks, we can remove this check (and we can unify do_wait_thread() and
ptrace_do_wait()).

This change can confuse the optimistic search in mm_update_next_owner(),
but this is fixable and minor.

Perhaps badness() and oom_kill_process() should be updated, but they
should be fixed in any case.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ratan Nalumasu <rnalumasu@gmail.com>
Cc: Vitaly Mayatskikh <vmayatsk@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17 15:45:31 -08:00
WANG Cong 3e26120cc7 kernel/sysctl.c: fix the incomplete part of sysctl_max_map_count-should-be-non-negative.patch
It is a mistake that we used 'proc_dointvec', it should be
'proc_dointvec_minmax', as in the original patch.

Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17 15:45:30 -08:00
Linus Torvalds 5a865c0606 Merge branch 'for-33' of git://repo.or.cz/linux-kbuild
* 'for-33' of git://repo.or.cz/linux-kbuild: (29 commits)
  net: fix for utsrelease.h moving to generated
  gen_init_cpio: fixed fwrite warning
  kbuild: fix make clean after mismerge
  kbuild: generate modules.builtin
  genksyms: properly consider  EXPORT_UNUSED_SYMBOL{,_GPL}()
  score: add asm/asm-offsets.h wrapper
  unifdef: update to upstream revision 1.190
  kbuild: specify absolute paths for cscope
  kbuild: create include/generated in silentoldconfig
  scripts/package: deb-pkg: use fakeroot if available
  scripts/package: add KBUILD_PKG_ROOTCMD variable
  scripts/package: tar-pkg: use tar --owner=root
  Kbuild: clean up marker
  net: add net_tstamp.h to headers_install
  kbuild: move utsrelease.h to include/generated
  kbuild: move autoconf.h to include/generated
  drop explicit include of autoconf.h
  kbuild: move compile.h to include/generated
  kbuild: drop include/asm
  kbuild: do not check for include/asm-$ARCH
  ...

Fixed non-conflicting clean merge of modpost.c as per comments from
Stephen Rothwell (modpost.c had grown an include of linux/autoconf.h
that needed to be changed to generated/autoconf.h)
2009-12-17 07:23:42 -08:00
Peter Zijlstra 077614ee1e sched: Fix broken assertion
There's a preemption race in the set_task_cpu() debug check in
that when we get preempted after setting task->state we'd still
be on the rq proper, but fail the test.

Check for preempted tasks, since those are always on the RQ.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.137155561@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 13:22:46 +01:00
Peter Zijlstra 5d27c23df0 perf events: Dont report side-band events on each cpu for per-task-per-cpu events
Acme noticed that his FORK/MMAP numbers were inflated by about
the same factor as his cpu-count.

This led to the discovery of a few more sites that need to
respect the event->cpu filter.

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091217121830.215333434@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 13:21:36 +01:00
Frederic Weisbecker 61c1917f47 perf events, x86/stacktrace: Make stack walking optional
The current print_context_stack helper that does the stack
walking job is good for usual stacktraces as it walks through
all the stack and reports even addresses that look unreliable,
which is nice when we don't have frame pointers for example.

But we have users like perf that only require reliable
stacktraces, and those may want a more adapted stack walker, so
lets make this function a callback in stacktrace_ops that users
can tune for their needs.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1261024834-5336-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 09:56:19 +01:00
Frederic Weisbecker 234da7bcdc sched: Teach might_sleep() about preemptible RCU
In practice, it is harmless to voluntarily sleep in a
rcu_read_lock() section if we are running under preempt rcu, but
it is illegal if we build a kernel running non-preemptable rcu.

Currently, might_sleep() doesn't notice sleepable operations
under rcu_read_lock() sections if we are running under
preemptable rcu because preempt_count() is left untouched after
rcu_read_lock() in this case. But we want developers who test
their changes under such config to notice the "sleeping while
atomic" issues.

So we add rcu_read_lock_nesting to prempt_count() in
might_sleep() checks.

[ v2: Handle rcu-tiny ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1260991265-8451-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 09:46:44 +01:00
Masami Hiramatsu 6f3cf44047 kprobe-tracer: Check new event/group name
Check new event/group name is same syntax as a C symbol. In other
words, checking the name is as like as other tracepoint events.

This can prevent user to create an event with useless name (e.g.
foo|bar, foo*bar).

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091216222408.14459.68790.stgit@dhcp-100-2-132.bos.redhat.com>
[ v2: minor cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 09:42:44 +01:00
Ingo Molnar 416eb39556 sched: Make warning less noisy
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.807938893@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-17 06:05:49 +01:00
Rusty Russell 62ac127950 cpumask: avoid dereferencing struct cpumask
struct cpumask will be undefined soon with CONFIG_CPUMASK_OFFSTACK=y,
to avoid them being declared on the stack.

cpumask_bits() does what we want here (of course, this code is crap).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
To: Thomas Gleixner <tglx@linutronix.de>
2009-12-17 11:43:29 +10:30
Rusty Russell f6325e30eb cpumask: use cpu_online in kernel/perf_event.c
Also, we want to check against nr_cpu_ids, not num_possible_cpus().
The latter works, but the correct bounds check is < nr_cpu_ids.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
To: Thomas Gleixner <tglx@linutronix.de>
2009-12-17 11:43:11 +10:30
Simon Horman cf1e367ee8 timers: Remove duplicate setting of new_base in __mod_timer()
new_base is set using per_cpu(tvec_bases, cpu) after selecting the
desired value of cpu immediately below so this line is a unnecessary.

Signed-off-by: Simon Horman <horms@verge.net.au>
LKML-Reference: <20091217001542.GD25317@verge.net.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-17 01:30:49 +01:00
David Howells 6e14154676 NOMMU: Optimise away the {dac_,}mmap_min_addr tests
In NOMMU mode clamp dac_mmap_min_addr to zero to cause the tests on it to be
skipped by the compiler.  We do this as the minimum mmap address doesn't make
any sense in NOMMU mode.

mmap_min_addr and round_hint_to_min() can be discarded entirely in NOMMU mode.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-12-17 09:25:19 +11:00
Andi Kleen 61cf693159 [sysctl] Fix breakage on systems with older glibc
As predicted during code review, the sysctl(2) changes made systems with
old glibc nearly unusable.  About every command gives a:

  warning: process `ls' used the deprecated sysctl system call with 1.4

warning in the log.

I see this on a SUSE 10.0 system with glibc 2.3.5.

Don't warn for this common case.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 12:36:18 -08:00
Linus Torvalds 8aedf8a6ae Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits)
  perf record: Use per-task-per-cpu events for inherited events
  perf record: Properly synchronize child creation
  perf events: Allow per-task-per-cpu counters
  perf diff: Percent calcs should use double values
  perf diff: Change the default sort order to "dso,symbol"
  perf diff: Use perf_session__fprintf_hists just like 'perf record'
  perf report: Fix cut'n'paste error recently introduced
  perf session: Move perf report specific hits out of perf_session__fprintf_hists
  perf tools: Move hist entries printing routines from perf report
  perf report: Generalize perf_session__fprintf_hists()
  perf symbols: Move symbol filtering to event__preprocess_sample()
  perf symbols: Adopt the strlists for dso, comm
  perf symbols: Make symbol_conf global
  perf probe: Fix to show which probe point is not found
  perf probe: Check symbols in symtab/kallsyms
  perf probe: Check build-id of vmlinux
  perf probe: Reject second attempt of adding same-name event
  perf probe: Support event name for --add option
  perf probe: Add glob matching support on --del
  perf probe: Use strlist__for_each macros in probe-event.c
  ...
2009-12-16 12:32:47 -08:00
Linus Torvalds da184a8064 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Fix return of trace_dump_stack()
  ksym_tracer: Fix bad cast
  tracing/power: Remove two exports
  tracing: Change event->profile_count to be int type
  tracing: Simplify trace_option_write()
  tracing: Remove useless trace option
  tracing: Use seq file for trace_clock
  tracing: Use seq file for trace_options
  function-graph: Allow writing the same val to set_graph_function
  ftrace: Call trace_parser_clear() properly
  ftrace: Return EINVAL when writing invalid val to set_ftrace_filter
  tracing: Move a printk out of ftrace_raw_reg_event_foo()
  tracing: Pull up calls to trace_define_common_fields()
  tracing: Extract duplicate ftrace_raw_init_event_foo()
  ftrace.h: Use common pr_info fmt string
  tracing: Add stack trace to irqsoff tracer
  tracing: Add trace_dump_stack()
  ring-buffer: Move resize integrity check under reader lock
  ring-buffer: Use sync sched protection on ring buffer resizing
  tracing: Fix wrong usage of strstrip in trace_ksyms
2009-12-16 12:02:25 -08:00
Linus Torvalds 74f3ae7434 Merge branch 'module' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'module' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  modpost: fix segfault with short symbol names
  module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y
  Kbuild: clear marker out of modpost
  module: make MODULE_SYMBOL_PREFIX into a CONFIG option
  ARM: unexport symbols used to implement floating point emulation
  ARM: use unified discard definition in linker script
  x86: don't export inline function
  sparc64: don't export static inline pci_ functions
2009-12-16 10:47:24 -08:00
Linus Torvalds 60d9aa758c Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6: (90 commits)
  jffs2: Fix long-standing bug with symlink garbage collection.
  mtd: OneNAND: Fix test of unsigned in onenand_otp_walk()
  mtd: cfi_cmdset_0002, fix lock imbalance
  Revert "mtd: move mxcnd_remove to .exit.text"
  mtd: m25p80: add support for Macronix MX25L4005A
  kmsg_dump: fix build for CONFIG_PRINTK=n
  mtd: nandsim: add support for 4KiB pages
  mtd: mtdoops: refactor as a kmsg_dumper
  mtd: mtdoops: make record size configurable
  mtd: mtdoops: limit the maximum mtd partition size
  mtd: mtdoops: keep track of used/unused pages in an array
  mtd: mtdoops: several minor cleanups
  core: Add kernel message dumper to call on oopses and panics
  mtd: add ARM pismo support
  mtd: pxa3xx_nand: Fix PIO data transfer
  mtd: nand: fix multi-chip suspend problem
  mtd: add support for switching old SST chips into QRY mode
  mtd: fix M29W800D dev_id and uaddr
  mtd: don't use PF_MEMALLOC
  mtd: Add bad block table overrides to Davinci NAND driver
  ...

Fixed up conflicts (mostly trivial) in
	drivers/mtd/devices/m25p80.c
	drivers/mtd/maps/pcmciamtd.c
	drivers/mtd/nand/pxa3xx_nand.c
	kernel/printk.c
2009-12-16 10:23:43 -08:00
Peter Zijlstra 738d2be430 sched: Simplify set_task_cpu()
Rearrange code a bit now that its a simpler function.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.269101883@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:59 +01:00
Peter Zijlstra 88ec22d3ed sched: Remove the cfs_rq dependency from set_task_cpu()
In order to remove the cfs_rq dependency from set_task_cpu() we
need to ensure the task is cfs_rq invariant for all callsites.

The simple approach is to substract cfs_rq->min_vruntime from
se->vruntime on dequeue, and add cfs_rq->min_vruntime on
enqueue.

However, this has the downside of breaking FAIR_SLEEPERS since
we loose the old vruntime as we only maintain the relative
position.

To solve this, we observe that we only migrate runnable tasks,
we do this using deactivate_task(.sleep=0) and
activate_task(.wakeup=0), therefore we can restrain the
min_vruntime invariance to that state.

The only other case is wakeup balancing, since we want to
maintain the old vruntime we cannot make it relative on dequeue,
but since we don't migrate inactive tasks, we can do so right
before we activate it again.

This is where we need the new pre-wakeup hook, we need to call
this while still holding the old rq->lock. We could fold it into
->select_task_rq(), but since that has multiple callsites and
would obfuscate the locking requirements, that seems like a
fudge.

This leaves the fork() case, simply make sure that ->task_fork()
leaves the ->vruntime in a relative state.

This covers all cases where set_task_cpu() gets called, and
ensures it sees a relative vruntime.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.191697025@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:58 +01:00
Peter Zijlstra efbbd05a59 sched: Add pre and post wakeup hooks
As will be apparent in the next patch, we need a pre wakeup hook
for sched_fair task migration, hence rename the post wakeup hook
and one pre wakeup.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.114746117@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:58 +01:00
Peter Zijlstra 881232b70b sched: Move kthread_bind() back to kthread.c
Since kthread_bind() lost its dependencies on sched.c, move it
back where it came from.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170518.039524041@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:57 +01:00
Peter Zijlstra 5da9a0fb67 sched: Fix select_task_rq() vs hotplug issues
Since select_task_rq() is now responsible for guaranteeing
->cpus_allowed and cpu_active_mask, we need to verify this.

select_task_rq_rt() can blindly return
smp_processor_id()/task_cpu() without checking the valid masks,
select_task_rq_fair() can do the same in the rare case that all
SD_flags are disabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.961475466@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:57 +01:00
Peter Zijlstra 3802290628 sched: Fix sched_exec() balancing
Since we access ->cpus_allowed without holding rq->lock we need
a retry loop to validate the result, this comes for near free
when we merge sched_migrate_task() into sched_exec() since that
already does the needed check.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.884743662@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:56 +01:00
Peter Zijlstra e2912009fb sched: Ensure set_task_cpu() is never called on blocked tasks
In order to clean up the set_task_cpu() rq dependencies we need
to ensure it is never called on blocked tasks because such usage
does not pair with consistent rq->lock usage.

This puts the migration burden on ttwu().

Furthermore we need to close a race against changing
->cpus_allowed, since select_task_rq() runs with only preemption
disabled.

For sched_fork() this is safe because the child isn't in the
tasklist yet, for wakeup we fix this by synchronizing
set_cpus_allowed_ptr() against TASK_WAKING, which leaves
sched_exec to be a problem

This also closes a hole in (6ad4c1888 sched: Fix balance vs
hotplug race) where ->select_task_rq() doesn't validate the
result against the sched_domain/root_domain.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.807938893@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:56 +01:00
Peter Zijlstra 06b83b5fbe sched: Use TASK_WAKING for fork wakups
For later convenience use TASK_WAKING for fresh tasks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.732561278@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:55 +01:00
Peter Zijlstra e4f4288842 sched: Select_task_rq_fair() must honour SD_LOAD_BALANCE
We should skip !SD_LOAD_BALANCE domains.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.653578430@chello.nl>
CC: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:55 +01:00
Peter Zijlstra e6c8fba777 sched: Fix task_hot() test order
Make sure not to access sched_fair fields before verifying it is
indeed a sched_fair task.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
CC: stable@kernel.org
LKML-Reference: <20091216170517.577998058@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:54 +01:00
Xiaotian Feng 9ee349ad6d sched: Fix set_cpu_active() in cpu_down()
Sachin found cpu hotplug test failures on powerpc, which made
the kernel hang on his POWER box.

The problem is that we fail to re-activate a cpu when a
hot-unplug fails. Fix this by moving the de-activation into
_cpu_down after doing the initial checks.

Remove the synchronize_sched() calls and rely on those implied
by rebuilding the sched domains using the new mask.

Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Tested-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091216170517.500272612@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 19:01:53 +01:00
Ingo Molnar ee1156c11a Merge branch 'linus' into sched/urgent
Conflicts:
	kernel/sched_idletask.c

Merge reason: resolve the conflicts, pick up latest changes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 18:33:49 +01:00
Peter Zijlstra f4c4176f21 perf events: Allow per-task-per-cpu counters
In order to allow for per-task-per-cpu counters, useful for
scalability when profiling task hierarchies, we allow installing
events with event->cpu != -1 in task contexts.

__perf_event_sched_in() already skips events where ->cpu
mis-matches the current cpu, fix up __perf_install_in_context()
and __perf_event_enable() to also respect this filter.

This does lead to vary hard to interpret enabled/running times
for such counters, but I don't see a simple solution for that.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: fweisbec@gmail.com
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091216165904.831451147@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-12-16 18:30:11 +01:00
Amerigo Wang 06a7f71124 kexec: premit reduction of the reserved memory size
Implement shrinking the reserved memory for crash kernel, if it is more
than enough.

For example, if you have already reserved 128M, now you just want 100M,
you can do:

# echo $((100*1024*1024)) > /sys/kernel/kexec_crash_size

Note, you can only do this before loading the crash kernel.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:13 -08:00
André Goddard Rosa 417e315247 pid: reduce code size by using a pointer to iterate over array
It decreases code size by 16 bytes on my gcc 4.4.1 on Core 2:
  text    data     bss     dec     hex filename
  4314    2216       8    6538    198a kernel/pid.o-BEFORE
  4298    2216       8    6522    197a kernel/pid.o-AFTER

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:12 -08:00
André Goddard Rosa 7be6d991bc pid: tighten pidmap spinlock critical section by removing kfree()
Avoid calling kfree() under pidmap spinlock, calling it afterwards.

Normally kfree() is fast, but sometimes it can be slow, so avoid
calling it under the spinlock if we can do it.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:12 -08:00
Oleg Nesterov 1be53963b0 signals: check ->group_stop_count after tracehook_get_signal()
Move the call to do_signal_stop() down, after tracehook call.  This makes
->group_stop_count condition visible to tracers before do_signal_stop()
will participate in this group-stop.

Currently the patch has no effect, tracehook_get_signal() always returns 0.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:09 -08:00
Oleg Nesterov ad09750b51 signals: kill force_sig_specific()
Kill force_sig_specific(), this trivial wrapper has no callers.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:09 -08:00
Oleg Nesterov 7486e5d9fc signals: cosmetic, collect_signal: use SI_USER
Trivial, s/0/SI_USER/ in collect_signal() for grep.

This is a bit confusing, we don't know the source of this signal.
But we don't care, and "info->si_code = 0" is imho worse.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:09 -08:00
Oleg Nesterov dd34200adc signals: send_signal: use si_fromuser() to detect from_ancestor_ns
Change send_signal() to use si_fromuser().  From now SEND_SIG_NOINFO
triggers the "from_ancestor_ns" check.

This fixes reparent_thread()->group_send_sig_info(pdeath_signal)
behaviour, before this patch send_signal() does not detect the
cross-namespace case when the child of the dying parent belongs to the
sub-namespace.

This patch can affect the behaviour of send_sig(), kill_pgrp() and
kill_pid() when the caller sends the signal to the sub-namespace with
"priv == 0" but surprisingly all callers seem to use them correctly,
including disassociate_ctty(on_exit).

Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly use
send_sig(priv => 0).  But his is minor and should be fixed anyway.

Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:09 -08:00
Oleg Nesterov 614c517d7c signals: SEND_SIG_NOINFO should be considered as SI_FROMUSER()
No changes in compiled code. The patch adds the new helper, si_fromuser()
and changes check_kill_permission() to use this helper.

The real effect of this patch is that from now we "officially" consider
SEND_SIG_NOINFO signal as "from user-space" signals. This is already true
if we look at the code which uses SEND_SIG_NOINFO, except __send_signal()
has another opinion - see the next patch.

The naming of these special SEND_SIG_XXX siginfo's is really bad
imho.  From __send_signal()'s pov they mean

	SEND_SIG_NOINFO		from user
	SEND_SIG_PRIV		from kernel
	SEND_SIG_FORCED		no info

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:08 -08:00
Oleg Nesterov 6580807da1 ptrace: copy_process() should disable stepping
If the tracee calls fork() after PTRACE_SINGLESTEP, the forked child
starts with TIF_SINGLESTEP/X86_EFLAGS_TF bits copied from ptraced parent.
This is not right, especially when the new child is not auto-attaced: in
this case it is killed by SIGTRAP.

Change copy_process() to call user_disable_single_step(). Tested on x86.

Test-case:

	#include <stdio.h>
	#include <unistd.h>
	#include <signal.h>
	#include <sys/ptrace.h>
	#include <sys/wait.h>
	#include <assert.h>

	int main(void)
	{
		int pid, status;

		if (!(pid = fork())) {
			assert(ptrace(PTRACE_TRACEME) == 0);
			kill(getpid(), SIGSTOP);

			if (!fork()) {
				/* kernel bug: this child will be killed by SIGTRAP */
				printf("Hello world\n");
				return 43;
			}

			wait(&status);
			return WEXITSTATUS(status);
		}

		for (;;) {
			assert(pid == wait(&status));
			if (WIFEXITED(status))
				break;
			assert(ptrace(PTRACE_SINGLESTEP, pid, 0,0) == 0);
		}

		assert(WEXITSTATUS(status) == 43);
		return 0;
	}

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:08 -08:00
KAMEZAWA Hiroyuki 569b846df5 memcg: coalesce uncharge during unmap/truncate
In massive parallel enviroment, res_counter can be a performance
bottleneck.  One strong techinque to reduce lock contention is reducing
calls by coalescing some amount of calls into one.

Considering charge/uncharge chatacteristic,
	- charge is done one by one via demand-paging.
	- uncharge is done by
		- in chunk at munmap, truncate, exit, execve...
		- one by one via vmscan/paging.

It seems we have a chance to coalesce uncharges for improving scalability
at unmap/truncation.

This patch is a for coalescing uncharge.  For avoiding scattering memcg's
structure to functions under /mm, this patch adds memcg batch uncharge
information to the task.  A reason for per-task batching is for making use
of caller's context information.  We do batched uncharge (deleyed
uncharge) when truncation/unmap occurs but do direct uncharge when
uncharge is called by memory reclaim (vmscan.c).

The degree of coalescing depends on callers
  - at invalidate/trucate... pagevec size
  - at unmap ....ZAP_BLOCK_SIZE
(memory itself will be freed in this degree.)
Then, we'll not coalescing too much.

On x86-64 8cpu server, I tested overheads of memcg at page fault by
running a program which does map/fault/unmap in a loop. Running
a task per a cpu by taskset and see sum of the number of page faults
in 60secs.

[without memcg config]
  40156968  page-faults              #      0.085 M/sec   ( +-   0.046% )
  27.67 cache-miss/faults
[root cgroup]
  36659599  page-faults              #      0.077 M/sec   ( +-   0.247% )
  31.58 miss/faults
[in a child cgroup]
  18444157  page-faults              #      0.039 M/sec   ( +-   0.133% )
  69.96 miss/faults
[child with this patch]
  27133719  page-faults              #      0.057 M/sec   ( +-   0.155% )
  47.16 miss/faults

We can see some amounts of improvement.
(root cgroup doesn't affected by this patch)
Another patch for "charge" will follow this and above will be improved more.

Changelog(since 2009/10/02):
 - renamed filed of memcg_batch (as pages to bytes, memsw to memsw_bytes)
 - some clean up and commentary/description updates.
 - added initialize code to copy_process(). (possible bug fix)

Changelog(old):
 - fixed !CONFIG_MEM_CGROUP case.
 - rebased onto the latest mmotm + softlimit fix patches.
 - unified patch for callers
 - added commetns.
 - make ->do_batch as bool.
 - removed css_get() at el. We don't need it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:07 -08:00
Alexey Dobriyan 28dfef8feb const: constify remaining pipe_buf_operations
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:05 -08:00
Barry Song f065f41f48 timecompare: fix half-Y2K38 problem in timecompare_update while calculating offset
ktime will overflow from 03:14:07 UTC on Tuesday, 19 January 2038,
ktime_add() in timecompare_update() will overflow a half earlier.  As a
result, wrong offset will be gotten, then cause some strange problems.

Signed-off-by: Barry Song <21cnbao@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Patrick Ohly <patrick.ohly@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:19:57 -08:00