Commit Graph

24 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
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
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
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
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
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
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
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
Mike Travis
608dfddd84 oprofile: change cpu_buffer from array to per_cpu variable
Change cpu_buffer from array to per_cpu variable in oprofile functions.

[akpm@linux-foundation.org: coding-style fixes]
Cc: Philippe Elie <phil.el@wanadoo.fr>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:31 -07:00
Philippe Elie
df9d177aa2 oProfile: oops when profile_pc() returns ~0LU
Instruction pointer returned by profile_pc() can be a random value.  This
break the assumption than we can safely set struct op_sample.eip field to a
magic value to signal to the per-cpu buffer reader side special event like
task switch ending up in a segfault in get_task_mm() when profile_pc()
return ~0UL.  Fixed by sanitizing the sampled eip and reject/log invalid
eip.

Problem reported by Sami Farin, patch tested by him.

Signed-off-by: Philippe Elie <phil.el@wanadoo.fr>
Tested-by: Sami Farin <safari-kernel@safari.iki.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:37 -08:00
David Howells
c4028958b6 WorkStruct: make allyesconfig
Fix up for make allyesconfig.

Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22 14:57:56 +00:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00