Commit graph

86 commits

Author SHA1 Message Date
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
Linus Torvalds
4ce5f24193 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: (31 commits)
  powerpc/oprofile: fix whitespaces in op_model_cell.c
  powerpc/oprofile: IBM CELL: add SPU event profiling support
  powerpc/oprofile: fix cell/pr_util.h
  powerpc/oprofile: IBM CELL: cleanup and restructuring
  oprofile: make new cpu buffer functions part of the api
  oprofile: remove #ifdef CONFIG_OPROFILE_IBS in non-ibs code
  ring_buffer: fix ring_buffer_event_length()
  oprofile: use new data sample format for ibs
  oprofile: add op_cpu_buffer_get_data()
  oprofile: add op_cpu_buffer_add_data()
  oprofile: rework implementation of cpu buffer events
  oprofile: modify op_cpu_buffer_read_entry()
  oprofile: add op_cpu_buffer_write_reserve()
  oprofile: rename variables in add_ibs_begin()
  oprofile: rename add_sample() in cpu_buffer.c
  oprofile: rename variable ibs_allowed to has_ibs in op_model_amd.c
  oprofile: making add_sample_entry() inline
  oprofile: remove backtrace code for ibs
  oprofile: remove unused ibs macro
  oprofile: remove unused components in struct oprofile_cpu_buffer
  ...
2009-01-09 12:43:06 -08:00
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
bd7dc46f77 oprofile: add op_cpu_buffer_get_data()
This function provides access to attached data of a sample. It returns
the size of data including the current value. Also,
op_cpu_buffer_get_size() is available to check if there is data
attached.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:45:46 +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
d358e75fc4 oprofile: rename variables in add_ibs_begin()
This unifies usage of variable names within oprofile.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 22:35:42 +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
6368a1f4d9 oprofile: making add_sample_entry() inline
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 17:06:47 +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
dbe6e2835e oprofile: simplify add_ibs_begin()
Signed-off-by: Robert Richter <robert.richter@amd.com>
2009-01-07 17:05:44 +01:00
Al Viro
56ff5efad9 zero i_uid/i_gid on inode allocation
... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Nick Piggin
c2452f3278 shrink struct dentry
struct dentry is one of the most critical structures in the kernel. So it's
sad to see it going neglected.

With CONFIG_PROFILING turned on (which is probably the common case at least
for distros and kernel developers), sizeof(struct dcache) == 208 here
(64-bit). This gives 19 objects per slab.

I packed d_mounted into a hole, and took another 4 bytes off the inline
name length to take the padding out from the end of the structure. This
shinks it to 200 bytes. I could have gone the other way and increased the
length to 40, but I'm aiming for a magic number, read on...

I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant:
why was this ever a good idea? The cookie system should increase its hash
size or use a tree or something if lookups are a problem. Also the "fast
dcookie lookups" in oprofile should be moved into the dcookie code -- how
can oprofile possibly care about the dcookie_mutex? It gets dropped after
get_dcookie() returns so it can't be providing any sort of protection.

At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system
with ~140 000 entries allocated. 192 is also a multiple of 64, so we get
nice cacheline alignment on 64 and 32 byte line systems -- any given dentry
will now require 3 cachelines to touch all fields wheras previously it
would require 4.

I know the inline name size was chosen quite carefully, however with the
reduction in cacheline footprint, it should actually be just about as fast
to do a name lookup for a 36 character name as it was before the patch (and
faster for other sizes). The memory footprint savings for names which are
<= 32 or > 36 bytes long should more than make up for the memory cost for
33-36 byte names.

Performance is a feature...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:38 -05:00
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
317f33bce6 oprofile: simplify sync_buffer()
Make code more readable. No functional changes.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 18:53:40 +01:00
Robert Richter
9741b309bb oprofile: simplify add_sample()
This patch removes add_us_sample() and simplifies add_sample(). Code
is much more readable now.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-29 18:53:26 +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
bf589e3296 oprofile: adding cpu_buffer_entries()
This is in preparation for changes in the cpu buffer implementation.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:15 +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
37ca5eb341 oprofile: set values to default when creating oprofilefs
This patch restores default values for:

/dev/oprofile/cpu_buffer_size
/dev/oprofile/buffer_watershed
/dev/oprofile/buffer_size

when creating the oprofilefs:

 # opcontrol --deinit
 # opcontrol --init
 # cat /dev/oprofile/cpu_buffer_size
 8192
 # echo 5123 > /dev/oprofile/cpu_buffer_size
 # cat /dev/oprofile/cpu_buffer_size
 5123
 # opcontrol --deinit
 # opcontrol --init
 # cat /dev/oprofile/cpu_buffer_size
 8192
 # opcontrol --deinit

This sets the values in a defined state. Before, there was no way to
restore the defaults without rebooting the system or reloading the
module.

Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:10 +01:00
Robert Richter
fd7826d56b oprofile: implement switch/case in buffer_sync.c
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:09 +01:00
Robert Richter
8dbc50c322 oprofile: fix typo
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10 14:20:06 +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
Nick Piggin
cae042a73b oprofile: fix memory ordering
Regular bitops don't work as locks on all architectures.

Also: can use non-atomic unlock as no concurrent stores to the word.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-27 19:15:41 +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
Barry Kasindorf
9b1f261166 OProfile: Fix buffer synchronization for IBS
The patch is needed since there is some IBS code in add_ibs_begin()
that handles more than one sample per iteration. This requires calling
get_slots() during each loop.

This fixes the current problem, but a proper solution that reworks the
cpu buffer synchronization is needed here in the future.

Signed-off-by: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-20 13:44:21 +02:00
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
8655a3b872 x86/oprofile: removing unused function parameter in add_ibs_begin()
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-15 20:56:49 +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
c92960fccb oprofile: whitespace fixes
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-15 20:47:41 +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