The perf_output_sample_ustack in kernel/events/core.c only writes
a single 64 bit word if it can't dump the user registers. From the
current version of the man page, I would have expected two 64 bit
words (one for size, one for dyn_size). Change the man page to
make this behavior explicit.
Reviewed-by: Vince Weaver <vincent.weaver@maine.edu>
Linux 4.1 added the possibility of perf_event_open() returning
EBUSY if an existing exclusive event controls the PMU.
This was introduced by the following commit:
commit bed5b25ad9c8a2f5d735ef0bc746ec870c01c1b0
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: Fri Jan 30 12:31:06 2015 +0200
perf: Add a pmu capability for "exclusive" events
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The rdpmc instruction allows reading performance counters directly
from usersapce. Prior to Linux 4.0 any process could use this
instruction when a perf event was running, even if the process itself
did not have any open. The following changesets changed the default
behavior so that only processes with active events can use rdpmc.
Note this change broke the ABI. Previously:
/sys/bus/event_source/devices/cpu/rdpmc
Set to "1" meant allow across whole system.
After the change "2" means the whole system, and "1" means per-process.
Probably a better change would have been to add "2" to mean per-process
and make that the default setting. Probably too late to fix that now.
commit a66734297f78707ce39d756b656bfae861d53f62
Author: Andy Lutomirski <luto@amacapital.net>
perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
commit 7911d3f7af14a614617e38245fedf98a724e46a9
Author: Andy Lutomirski <luto@amacapital.net>
perf/x86: Only allow rdpmc if a perf_event is mapped
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/caac3c1c707dcca48ecbc35f4def21495856f479.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the PERF_RECORD_ITRACE_START
record type in the following commit:
commit ec0d7729bbaed4b9d2d3fada693278e13a3d1368
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
perf: Add ITRACE_START record to indicate that tracing has started
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-15-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the aux_watermark attr
field in the following commit:
commit 1a5941312414c71dece6717da9a0fa1303127afa
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
perf: Add wakeup watermark control to the AUX area
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-10-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the AUX sample flag
AUX_FLAG_OVERWRITE as added in the following commit:
commit 2023a0d2829e521fe6ad6b9907f3f90bfbf57142
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
perf: Support overwrite mode for the AUX area
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-9-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the AUX sample type
as added in the following commit:
commit 68db7e98c3a6ebe7284b6cf14906ed7c55f3f7f0
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
perf: Add AUX record
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-7-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the AUX mmap region
as added in the following commit:
commit 45bfb2e50471abbbfd83d40d28c986078b0d24ff
Author: Peter Zijlstra <peterz@infradead.org>
perf: Add AUX area to ring buffer for raw data streams
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-3-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the data_offset
and data_size fields to the perf_event mmap buffer, as added
in the following commit:
commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>
perf: Add data_{offset,size} to user_page
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the
PERF_EVENT_IOC_SET_BPF ioctl in the following commit:
commit 2541517c32be2531e0da59dfd7efc1ce844644f5
Author: Alexei Starovoitov <ast@plumgrid.com>
tracing, perf: Implement BPF programs attached to kprobes
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the clockid
functionaliry added in the following commit:
commit 34f439278cef7b1177f8ce24f9fc81dfc6221d3b
Author: Peter Zijlstra <peterz@infradead.org>
perf: Add per event clockid support
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This manpage patch relates to the addition of the
PERF_SAMPLE_BRANCH_CALL_STACK functionaliry added in the
following commit:
commit 2c44b1936bb3b135a3fac8b3493394d42e51cf70
Author: Peter Zijlstra <peterz@infradead.org>
perf/x86/intel: Expose LBR callstack to user space tooling
With LBR call stack feature enable, there are three callchain options.
Enable the 3rd callchain option (LBR callstack) to user space tooling.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/20141105093759.GQ10501@worktop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch relates to the exclude_host and exclude_guest bits added
by the following commit:
exclude_host, exclude_guest; Linux 3.2
commit a240f76165e6255384d4bdb8139895fac7988799
Author: Joerg Roedel <joerg.roedel@amd.com>
Date: Wed Oct 5 14:01:16 2011 +0200
perf, core: Introduce attrs to count in either host or guest mode
The updated manpage text clarifies that the "exclude_host" and
"exclude_guest" perf_event_open() attr bits only apply in the
context of a KVM environment and are currently x86 only.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch relates to the addition of PERF_SAMPLE_REGS_INTR
support added in the following commit:
perf_sample_regs_intr; Linux 3.19
commit 60e2364e60e86e81bc6377f49779779e6120977f
Author: Stephane Eranian <eranian@google.com>
perf: Add ability to sample machine state on interrupt
The primary difference between PERF_SAMPLE_REGS_INTR and the
existing PERF_SAMPLE_REGS_USER is that the new support will
return kernel register values. Also if precise_ip is
set higher than 0 then the PEBS register state will be returned
rather than the saved interrupt state.
This patch incorporates feedback from Stephane Eranian and
Andi Kleen.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Currently the PERF_EVENT_IOC_REFRESH ioctl, when applied to a group
leader, will refresh all children. Also if a refresh value of 0
is chosen then the refresh becomes infinite (never runs out).
Back in 2011 PAPI was relying on these behaviors but I was told
that both were unsupported and subject to being removed at any time.
(See https://lkml.org/lkml/2011/5/24/337 )
However the behavior has not been changed.
This patch updates the manpage to still list the behavior as
unsupported, but removes the inaccurate description of it
only being a problem with 2.6 kernels.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I noticed you were adding git commit references to the various
Linux version markers.
This adds git commit references for all Linux kernel version
notes in perf_event_open.2
mtk: I backed out two pieces of Vince's patch that were not
source comments. They can be dealt with as separate commits.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Update the perf_event_open manpage to be more consistent when
discussing overflow events. It merges the discussion of
poll-type notifications with those generated by SIGIO
signal handlers.
This addresses the remaining FIXMEs is the document.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Remove an inaccurate paragraph about values in the attr.config
field. This information was never true in any released kernel;
it somehow snuck into the manpage because it is still described
this way in tools/perf/design.txt in the kernel source tree.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This change clarifies the behavior of the PERF_FLAG_FD_OUTPUT and
PERF_FLAG_FD_NO_GROUP flags to perf_event_open(), and removes
the related FIXME comments.
While writing tests to validate the behavior of these flags I
discovered that PERF_FLAG_FD_OUTPUT has been broken since the
2.6.35 kernel release.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
There was a typo with the name of PERF_ATTR_SIZE_VER3
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Linux 3.16 (more specifically, commit 82b897782d10fcc4 )
added support for differentiating between process renames
caused by exec versus those caused by other methods.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Linux 3.16 (more specifically, commit a5a5ba72843dd05f9 )
enabled the enhanced mmap2 record support.
The interface was added in Linux 3.12 but disabled until
Linux 3.16.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
When checking the fields in the PERF_SAMPLE_DATA_SRC type samples
you need to shift the masks before doing the compare.
Although the value you are checking (perf_mem_data_src) is
specified as a bitfield so this might all fall apart if trying
to access the field in a cross-endian way. The Power people
were working on this issue, not sure if they resolved it.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This clarifies the PERF_SAMPLE_STACK_USER section.
I found these issue while implementing some code that uses
the option. The important change is fixing the name of the
sample_stack_user parameter, the rest is just some wording
fixes and minor clarifications.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Clarify the reasons for EACCES and EPERM errors.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Expand the perf_event_open.2 ERRORS section to be more comprehensive.
These were determined both by code inspection and by writing a large
number of test programs.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The Linux 3.14 release adds support for the PERF_FLAG_FD_CLOEXEC
flag.
The wording is based on the description in kernel commit
a21b0b354d4ac39be691f51c53562e2c24443d9e
by Yann Droneaud.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Linux 3.14 (in commit bad7192b842c83e580747ca57104dd51fe08c223)
changes the perf_event PERF_EVENT_IOC_PERIOD ioctl() behavior
on all architectures to update immediately, to match the behavior
found on ARM.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The following patch adds descriptions of the new perf_event_open.2
PERF_SAMPLE_TRANSACTION sample type as added in Linux 3.13.
The descriptions are based on information provided by Andi Kleen,
both in the e-mail
[PATCH 1/6] perf, core: Add generic transaction flags v5
sent to the linux-kernel list as well as an e-mail
[PATCH] Document transaction flags in perf_event_open manpage
sent to the linux-man list.
The implementation is based heavily on the Intel Haswell
processor. Documentation can be found at this page:
http://software.intel.com/en-us/blogs/2013/05/03/intelr-transactional-synchronization-extensions-intelr-tsx-profiling-with-linux-0
as well as in section 18.11.5.1 of volume 3 of the
Intel 64 and IA-32 Architecture Software Developer's Manual.
Also, someone with better manpage formatting skills than I have
should probably investigate why I can't get the last line of
the change to properly tab-align with the .I transaction
heading.
Cowritten-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Clarify the perf_event_open behavior with respect to the disabled
bit and creating event groups.
Reported-by: Sudhanshu Goswami <Sudhanshu.Goswami@emc.com>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Warn that using the perf_event_open "exclusive" bit, while it might seem
like a good idea, might lead to all 0 results in some common usage cases.
Reported-by: Sudhanshu Goswami <Sudhanshu.Goswami@emc.com>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Here's an updated version of [David Ahern's] patch that
expands the "mmap" definition as well as that of "mmap_data".
Also some manpage related formatting improvements from the
original patch.
Link: https://lkml.org/lkml/2013/11/11/505
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch attempts to clarify the pid and cpu options to
perf_event_open().
It does two things:
1. Tries to make clear that the "pid" argument can mean
process *or* thread. This is made confusing by
how Linux uses the terms mostly interchangeably.
2. The cpu/pid documentation was confusing because of
how the parameters are interdependent. Since there
are only 6 possible combinations I broke out the
possibilities into a table.
Reported-by: Manuel Selva <selva.manuel@gmail.com>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
It turns out that the perf_event mmap page rdpmc/time setting was
broken, dating back to the introduction of the feature. Due
to a mistake with a bitfield, two different values mapped to
the same feature bit.
A new somewhat backwards compatible interface was introduced
in Linux 3.12. A much longer report on the issue can be found
here:
https://lwn.net/Articles/567894/
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A new perf_event related ioctl, PERF_EVENT_IOC_ID, was added
in Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A new PERF_SAMPLE_IDENTIFIER sample type was added in Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Support for the PERF_COUNT_SW_DUMMY event type was added in
Linux 3.12.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The PERF_EVENT_IOC_PERIOD ioctl was broken until 2.6.36,
and it turns out that the ARM architecture has some
differing behavior too.
Reported-by: Andreas Sandberg <andreas.sandberg@it.uu.se>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The following documents the E2BIG error return for
perf_event_open().
I actually ran into this error the hard way and it took me
half a day to figure out why my ->size value was changing.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This started out as just adding the new perf_event_open features
from Linux 3.11 (which was the addition of transactional memory
defines for PERF_SAMPLE_BRANCH_STACK samples) but turned into a
general cleanup of the PERF_SAMPLE_BRANCH_STACK documentation.
The main clarification is that at least one of the non-privilege values
must be set or else perf_event_open will return an EINVAL error.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The indentation of the MMAP layout section wasn't quite right.
I think this improves things but I admit I'm not an expert at the
low-level indentation directives.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This improves the documentation of the various
perf_event_open()-related sysfs files.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
It turns out PERF_IOC_FLAG_GROUP was broken from 75f937f24bd9
(in Linux 2.6.31, the initial perf_event release) until
724b6daa1 (Linux 3.4).
I've done some extensive kernel source code digging plus
running tests of various kernels and I hope the info
presented is accurate now.
(Patch edited somewhat by mtk.)
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch updates the perf_event_open() documentation to include
new interfaces added in the 3.10 kernel.
It also documents a few [To be documented] instances left over
from the 3.7 kernel.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The perf_event_open() ENABLE/DISABLE/RESET ioctls can take an
argument, PERF_IOC_FLAG_GROUP. This wasn't documented at all
until about a year ago (despite the support being there from
the beginning) so I missed this when initially writing
the man page.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Clarify the perf_event_open() wakeup_events/wakeup_watermark
fields a bit, based on info from kernel commit cfeb1d90a1b1.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Capitalization in .SS sections across pages (and sometimes even
within a single page) is wildly inconsistent. Make it consistent.
Capitalize first word in heading, but otherwise use lower case,
except where English usage (e.g., proper nouns) or programming
language requirements (e.g., identifier names) dictate otherwise.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Keno Fischer