Commit Graph

58 Commits

Author SHA1 Message Date
Robert Richter 750d857c68 oprofile: fix crash when accessing freed task structs
This patch fixes a crash during shutdown reported below. The crash is
caused by accessing already freed task structs. The fix changes the
order for registering and unregistering notifier callbacks.

All notifiers must be initialized before buffers start working. To
stop buffer synchronization we cancel all workqueues, unregister the
notifier callback and then flush all buffers. After all of this we
finally can free all tasks listed.

This should avoid accessing freed tasks.

On 22.07.10 01:14:40, Benjamin Herrenschmidt wrote:

> So the initial observation is a spinlock bad magic followed by a crash
> in the spinlock debug code:
>
> [ 1541.586531] BUG: spinlock bad magic on CPU#5, events/5/136
> [ 1541.597564] Unable to handle kernel paging request for data at address 0x6b6b6b6b6b6b6d03
>
> Backtrace looks like:
>
>       spin_bug+0x74/0xd4
>       ._raw_spin_lock+0x48/0x184
>       ._spin_lock+0x10/0x24
>       .get_task_mm+0x28/0x8c
>       .sync_buffer+0x1b4/0x598
>       .wq_sync_buffer+0xa0/0xdc
>       .worker_thread+0x1d8/0x2a8
>       .kthread+0xa8/0xb4
>       .kernel_thread+0x54/0x70
>
> So we are accessing a freed task struct in the work queue when
> processing the samples.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-08-25 09:09:09 +02:00
Phil Carmody 9414e99672 oprofile: protect from not being in an IRQ context
http://lkml.org/lkml/2010/4/27/285

Protect against dereferencing regs when it's NULL, and
force a magic number into pc to prevent too deep processing.
This approach permits the dropped samples to be tallied as
invalid Instruction Pointer events.

e.g. output from about 15mins at 10kHz sample rate:
Nr. samples received: 2565380
Nr. samples lost invalid pc: 4

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-05-03 23:02:39 +02:00
Robert Richter b971f06187 Merge commit 'tip/tracing/core' into oprofile/core
Conflicts:
	drivers/oprofile/cpu_buffer.c

Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-04-23 16:47:51 +02:00
Andi Kleen cb6e943ccf oprofile: remove double ring buffering
oprofile used a double buffer scheme for its cpu event buffer
to avoid races on reading with the old locked ring buffer.

But that is obsolete now with the new ring buffer, so simply
use a single buffer. This greatly simplifies the code and avoids
a lot of sample drops on large runs, especially with call graph.

Based on suggestions from Steven Rostedt

For stable kernels from v2.6.32, but not earlier.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2010-04-23 15:30:38 +02:00
Steven Rostedt 66a8cb95ed ring-buffer: Add place holder recording of dropped events
Currently, when the ring buffer drops events, it does not record
the fact that it did so. It does inform the writer that the event
was dropped by returning a NULL event, but it does not put in any
place holder where the event was dropped.

This is not a trivial thing to add because the ring buffer mostly
runs in overwrite (flight recorder) mode. That is, when the ring
buffer is full, new data will overwrite old data.

In a produce/consumer mode, where new data is simply dropped when
the ring buffer is full, it is trivial to add the placeholder
for dropped events. When there's more room to write new data, then
a special event can be added to notify the reader about the dropped
events.

But in overwrite mode, any new write can overwrite events. A place
holder can not be inserted into the ring buffer since there never
may be room. A reader could also come in at anytime and miss the
placeholder.

Luckily, the way the ring buffer works, the read side can find out
if events were lost or not, and how many events. Everytime a write
takes place, if it overwrites the header page (the next read) it
updates a "overrun" variable that keeps track of the number of
lost events. When a reader swaps out a page from the ring buffer,
it can record this number, perfom the swap, and then check to
see if the number changed, and take the diff if it has, which would be
the number of events dropped. This can be stored by the reader
and returned to callers of the reader.

Since the reader page swap will fail if the writer moved the head
page since the time the reader page set up the swap, this gives room
to record the overruns without worrying about races. If the reader
sets up the pages, records the overrun, than performs the swap,
if the swap succeeds, then the overrun variable has not been
updated since the setup before the swap.

For binary readers of the ring buffer, a flag is set in the header
of each sub page (sub buffer) of the ring buffer. This flag is embedded
in the size field of the data on the sub buffer, in the 31st bit (the size
can be 32 or 64 bits depending on the architecture), but only 27
bits needs to be used for the actual size (less actually).

We could add a new field in the sub buffer header to also record the
number of events dropped since the last read, but this will change the
format of the binary ring buffer a bit too much. Perhaps this change can
be made if the information on the number of events dropped is considered
important enough.

Note, the notification of dropped events is only used by consuming reads
or peeking at the ring buffer. Iterating over the ring buffer does not
keep this information because the necessary data is only available when
a page swap is made, and the iterator does not swap out pages.

Cc: Robert Richter <robert.richter@amd.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-03-31 22:57:04 -04:00
Tejun Heo b3e9f672b6 percpu: make percpu symbols in oprofile unique
This patch updates percpu related symbols in oprofile such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/oprofile/cpu_buffer.c: s/cpu_buffer/op_cpu_buffer/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Robert Richter <robert.richter@amd.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-29 22:34:13 +09:00
Robert Richter 51563a0e56 x86/oprofile: introduce oprofile_add_data64()
The IBS implemention writes 64 bit register values to the cpu buffer
by writing two 32 values using oprofile_add_data(). This patch
introduces oprofile_add_data64() to write a single 64 bit value to the
buffer.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-06-11 20:16:00 +02:00
Robert Richter fecfe6320b oprofile: remove obselete include headers
This became obsolete with this commit:

 6dad828 oprofile: port to the new ring_buffer

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-06-11 16:10:12 +02:00
Robert Richter 54f2c841fa oprofile: fix cpu buffer size
The unit of oprofile_cpu_buffer_size is in samples, but was allocated
in bytes. This led to the allocation of too small cpu buffers. This
patch recalculates the buffer size in bytes taking also the
ring_buffer_event header size into account.

Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-05-07 17:28:59 +02:00
Ingo Molnar 304cc6ae1b ring_buffer: remove unused flags parameter, fix
Oprofile's ring-buffer use was not considered.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06 01:14:05 +01:00
Robert Richter fdb6a8f4db oprofile: fix uninitialized use of struct op_entry
Impact: fix crash

In case of losing samples struct op_entry could have been used
uninitialized causing e.g. a wrong preemption count or NULL pointer
access. This patch fixes this.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-17 17:26:39 +01:00
Robert Richter 14f0ca8eae oprofile: make new cpu buffer functions part of the api
This patch creates the new functions

 oprofile_write_reserve()
 oprofile_add_data()
 oprofile_write_commit()

and makes them part of the oprofile api.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:48:15 +01:00
Robert Richter ebf8d974e2 oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs code
The ifdefs can be removed since the code is no longer ibs specific and
can be used for other purposes as well. IBS specific code is only in
op_model_amd.c.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:47:56 +01:00
Robert Richter 1acda878e2 oprofile: use new data sample format for ibs
The new ring buffer implementation allows the storage of samples with
different size. This patch implements the usage of the new sample
format to store ibs samples in the cpu buffer. Until now, writing to
the cpu buffer could lead to incomplete sampling sequences since IBS
samples were transfered in multiple samples. Due to a full buffer,
data could be lost at any time. This can't happen any more since the
complete data is reserved in advance and then stored in a single
sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:47:23 +01:00
Robert Richter d9928c25a6 oprofile: add op_cpu_buffer_add_data()
This function can be used to attach data to a sample. It returns the
remaining free buffer size that has been reserved with
op_cpu_buffer_write_reserve().

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:41:47 +01:00
Robert Richter ae735e9964 oprofile: rework implementation of cpu buffer events
Special events such as task or context switches are marked with an
escape code in the cpu buffer followed by an event code or a task
identifier. There is one escape code per event. To make escape
sequences also available for data samples the internal cpu buffer
format must be changed. The current implementation does not allow the
extension of event codes since this would lead to collisions with the
task identifiers. To avoid this, this patch introduces an event mask
that allows the storage of multiple events with one escape code. Now,
task identifiers are stored in the data section of the sample. The
implementation also allows the usage of custom data in a sample. As a
side effect the new code is much more readable and easier to
understand.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:40:47 +01:00
Robert Richter 2d87b14cf8 oprofile: modify op_cpu_buffer_read_entry()
This implements the support of samples with attached data.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:40:02 +01:00
Robert Richter 2cc28b9f26 oprofile: add op_cpu_buffer_write_reserve()
This function prepares the cpu buffer to write a sample.

Struct op_entry is used during operations on the ring buffer while
struct op_sample contains the data that is stored in the ring
buffer. Struct entry can be uninitialized. The function reserves a
data array that is specified by size. Use op_cpu_buffer_write_commit()
after preparing the sample. In case of errors a null pointer is
returned, otherwise the pointer to the sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:37:44 +01:00
Robert Richter d0e233846d oprofile: rename add_sample() in cpu_buffer.c
Rename the fucntion to op_add_sample() since there is a collision with
another one with the same name in buffer_sync.c.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:35:26 +01:00
Robert Richter 8350c78734 oprofile: remove backtrace code for ibs
This code is broken since a TRACE_BEGIN_CODE is never sent to the
daemon. The data becomes corrupt since the backtrace is interpreted as
ibs sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 17:06:32 +01:00
Robert Richter f4ff236441 oprofile: remove unused ibs macro
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 17:06:16 +01:00
Robert Richter 8d15df84a4 oprofile: remove unused components in struct oprofile_cpu_buffer
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 17:06:00 +01:00
Robert Richter 3967e93e06 oprofile: simplify add_sample() in cpu_buffer.c
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-30 05:30:05 +01:00
Robert Richter 6352d92dec oprofile: simplify oprofile_begin_trace()
This patch removes the unused return parameter in
oprofile_begin_trace(). Also, oprofile_begin_trace() and
oprofile_end_trace() are inline now.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 18:54:44 +01:00
Robert Richter d45d23bed4 oprofile: add inline function __oprofile_add_ext_sample()
This patch adds the inline function __oprofile_add_ext_sample() to
cpu_buffer.c and thus reduces overhead when calling
oprofile_add_sample().

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 18:51:39 +01:00
Robert Richter 300157768f oprofile: reordering some code in cpu_buffer.c
Reordering code to keep alloc/free functions together.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 17:24:36 +01:00
Robert Richter 9966718dae oprofile: remove ring buffer inline functions in cpu_buffer.h
This patch moves ring buffer inline functions to cpu_buffer.c.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 15:19:19 +01:00
Robert Richter 6d2c53f3cd oprofile: rename cpu buffer functions
This patch renames cpu buffer functions to something more oprofile
specific names. Functions will be moved to the global name space.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 15:17:52 +01:00
Robert Richter bd2172f580 oprofile: rename kernel-wide identifiers
This patch renames kernel-wide identifiers to something more oprofile
specific names.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-16 17:52:49 +01:00
Robert Richter 211117ff09 oprofile: fix lost sample counter
The number of lost samples could be greater than the number of
received samples. This patches fixes this. The implementation
introduces return values for add_sample() and add_code().

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 20:25:15 +01:00
Robert Richter 1d7503b5dc oprofile: remove nr_available_slots()
This function is no longer available after the port to the new ring
buffer. Its removal can lead to incomplete sampling sequences since
IBS samples and backtraces are transfered in multiple samples. Due to
a full buffer, samples could be lost any time. The userspace daemon
has to live with such incomplete sampling sequences as long as the
data within one sample is consistent.

This will be fixed by changing the internal buffer data there all data
of one IBS sample or a backtrace is packed in a single ring buffer
entry. This is possible since the new ring buffer supports variable
data size.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 20:03:35 +01:00
Robert Richter 6dad828b76 oprofile: port to the new ring_buffer
This patch replaces the current oprofile cpu buffer implementation
with the ring buffer provided by the tracing framework. The motivation
here is to leave the pain of implementing ring buffers to others. Oh,
no, there are more advantages. Main reason is the support of different
sample sizes that could be stored in the buffer. Use cases for this
are IBS and Cell spu profiling. Using the new ring buffer ensures
valid and complete samples and allows copying the cpu buffer stateless
without knowing its content. Second it will use generic kernel API and
also reduce code size. And hopefully, there are less bugs.

Since the new tracing ring buffer implementation uses spin locks to
protect the buffer during read/write access, it is difficult to use
the buffer in an NMI handler. In this case, writing to the buffer by
the NMI handler (x86) could occur also during critical sections when
reading the buffer. To avoid this, there are 2 buffers for independent
read and write access. Read access is in process context only, write
access only in the NMI handler. If the read buffer runs empty, both
buffers are swapped atomically. There is potentially a small window
during swapping where the buffers are disabled and samples could be
lost.

Using 2 buffers is a little bit overhead, but the solution is clear
and does not require changes in the ring buffer implementation. It can
be changed to a single buffer solution when the ring buffer access is
implemented as non-locking atomic code.

The new buffer requires more size to store the same amount of samples
because each sample includes an u32 header. Also, there is more code
to execute for buffer access. Nonetheless, the buffer implementation
is proven in the ftrace environment and worth to use also in oprofile.

Patches that changes the internal IBS buffer usage will follow.

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:18 +01:00
Robert Richter fbc9bf9f0e oprofile: moving cpu_buffer_reset() to cpu_buffer.h
This is in preparation for changes in the cpu buffer implementation.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:16 +01:00
Robert Richter 229234ae4a oprofile: adding cpu_buffer_write_commit()
This is in preparation for changes in the cpu buffer implementation.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:14 +01:00
Robert Richter 7d468abee0 oprofile: adding cpu buffer r/w access functions
This is in preparation for changes in the cpu buffer implementation.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:13 +01:00
Robert Richter cdc1834d1a oprofile: whitspace changes only
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:05 +01:00
Robert Richter fd13f6c851 oprofile: comment cleanup
This fixes the coding style of some comments.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:01 +01:00
Linus Torvalds 92fb83afd6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile: (21 commits)
  OProfile: Fix buffer synchronization for IBS
  oprofile: hotplug cpu fix
  oprofile: fixing whitespaces in arch/x86/oprofile/*
  oprofile: fixing whitespaces in arch/x86/oprofile/*
  oprofile: fixing whitespaces in drivers/oprofile/*
  x86/oprofile: add the logic for enabling additional IBS bits
  x86/oprofile: reordering functions in nmi_int.c
  x86/oprofile: removing unused function parameter in add_ibs_begin()
  oprofile: more whitespace fixes
  oprofile: whitespace fixes
  OProfile: Rename IBS sysfs dir into "ibs_op"
  OProfile: Rework string handling in setup_ibs_files()
  OProfile: Rework oprofile_add_ibs_sample() function
  oprofile: discover counters for op ppro too
  oprofile: Implement Intel architectural perfmon support
  oprofile: Don't report Nehalem as core_2
  oprofile: drop const in num counters field
  Revert "Oprofile Multiplexing Patch"
  x86, oprofile: BUG: using smp_processor_id() in preemptible code
  x86/oprofile: fix on_each_cpu build error
  ...

Manually fixed trivial conflicts in
	drivers/oprofile/{cpu_buffer.c,event_buffer.h}
2008-10-23 10:05:40 -07:00
Carl Love a5598ca0d4 powerpc/oprofile: Fix mutex locking for cell spu-oprofile
The issue is the SPU code is not holding the kernel mutex lock while
adding samples to the kernel buffer.

This patch creates per SPU buffers to hold the data.  Data
is added to the buffers from in interrupt context.  The data
is periodically pushed to the kernel buffer via a new Oprofile
function oprofile_put_buff(). The oprofile_put_buff() function
is called via a work queue enabling the funtion to acquire the
mutex lock.

The existing user controls for adjusting the per CPU buffer
size is used to control the size of the per SPU buffers.
Similarly, overflows of the SPU buffers are reported by
incrementing the per CPU buffer stats.  This eliminates the
need to have architecture specific controls for the per SPU
buffers which is not acceptable to the OProfile user tool
maintainer.

The export of the oprofile add_event_entry() is removed as it
is no longer needed given this patch.

Note, this patch has not addressed the issue of indexing arrays
by the spu number.  This still needs to be fixed as the spu
numbering is not guarenteed to be 0 to max_num_spus-1.

Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Maynard Johnson <maynardj@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Acked-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-21 15:17:48 +11:00
Chris J Arges 4bd9b9dc97 oprofile: hotplug cpu fix
This patch addresses problems when hotplugging cpus while
profiling. Instead of allocating only online cpus, all possible cpu
buffers are allocated, which allows cpus to be onlined during
operation. If a cpu is offlined before profiling is shutdown
wq_sync_buffer checks for this condition then cancels this work and
does not sync this buffer.

Signed-off-by: Chris J Arges <arges@linux.vnet.ibm.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-17 10:38:58 +02:00
Robert Richter 6a18037d41 oprofile: fixing whitespaces in drivers/oprofile/*
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-16 15:01:40 +02:00
Robert Richter 25ad2913ca oprofile: more whitespace fixes
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-15 20:55:51 +02:00
Robert Richter e2fee2761a OProfile: Rework oprofile_add_ibs_sample() function
Code looks much more cleaner now.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-15 20:47:31 +02:00
Ingo Molnar accba5f396 Merge branch 'linus' into oprofile-v2
Conflicts:
	arch/x86/kernel/apic_32.c
	arch/x86/oprofile/nmi_int.c
	include/linux/pci_ids.h
2008-10-13 11:05:51 +02:00
Ingo Molnar 59293c8ad5 Merge commit 'v2.6.27-rc8' into oprofile
Conflicts:
	arch/x86/oprofile/nmi_int.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-30 12:16:26 +02:00
Carl Love f4156d1cd1 powerpc/cell/oprofile: Avoid double vfree of profile buffer
If an error occurs on opcontrol start, the event and per cpu buffers
are released.  If later opcontrol shutdown is called then the free
function will be called again to free buffers that no longer
exist.  This results in a kernel oops.  The following changes
prevent the call to delete buffers that don't exist.

Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-08-26 10:24:46 +10:00
Robert Richter bd17b625c0 oprofile: fix printk in cpu_buffer.c
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 11:48:14 +02:00
Robert Richter 852402cc27 x86/oprofile: add CONFIG_OPROFILE_IBS option
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 11:48:13 +02:00
Barry Kasindorf 345c25730d x86/oprofile: add IBS support for AMD CPUs, IBS buffer handling routines
This patchset supports the new profiling hardware available in the
latest AMD CPUs in the oProfile driver.

Signed-off-by: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-26 11:48:04 +02:00
Eric Dumazet 8b8b498836 oprofile: don't request cache line alignment for cpu_buffer
Alignment was previously requested because cpu_buffer was an [NR_CPUS]
array, to avoid cache line sharing between CPUS.

After commit 608dfddd84 (oprofile: change
cpu_buffer from array to per_cpu variable ), we dont need to force an
alignement anymore since cpu_buffer sits in per_cpu zone.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-14 19:11:12 -07:00