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path: root/drivers/oprofile/cpu_buffer.h
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2008-12-10oprofile: port to the new ring_bufferRobert Richter
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>
2008-12-10oprofile: moving cpu_buffer_reset() to cpu_buffer.hRobert Richter
This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10oprofile: adding cpu_buffer_entries()Robert Richter
This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10oprofile: adding cpu_buffer_write_commit()Robert Richter
This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-10oprofile: adding cpu buffer r/w access functionsRobert Richter
This is in preparation for changes in the cpu buffer implementation. Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-16oprofile: fixing whitespaces in drivers/oprofile/*Robert Richter
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-10-15oprofile: more whitespace fixesRobert Richter
Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-07-26x86/oprofile: add IBS support for AMD CPUs, IBS buffer handling routinesBarry Kasindorf
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>
2008-05-14oprofile: don't request cache line alignment for cpu_bufferEric Dumazet
Alignment was previously requested because cpu_buffer was an [NR_CPUS] array, to avoid cache line sharing between CPUS. After commit 608dfddd845da5ab6accef70154c8910529699f7 (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>
2008-04-28oprofile: change cpu_buffer from array to per_cpu variableMike Travis
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>
2007-11-14oProfile: oops when profile_pc() returns ~0LUPhilippe Elie
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>
2006-11-22WorkStruct: make allyesconfigDavid Howells
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!