cfb104ca8a
report/script/trace/top:
Arnaldo Carvalho de Melo:
- Allow specifying marker events demarcating when to consider the other events,
i.e. one now can state something like:
# perf probe kernel_function
# perf record -e cycles,probe:kernel_function
And then, in 'perf script' or 'perf report' say:
# perf report --switch-on=probe:kernel_function
And then the cycles event samples will be considered only after we
find the first probe:kernel_function event.
There is also --switch-off=event, to make it stop considering events
out of some window, say to avoid some winding down of a workload.
The same can be done with the "live mode" tools: 'perf top' and 'perf trace'.
There are examples in the cset comments showing how to use it with
SDT events in things like 'systemtap', that have those tracepoint-like
events for the start/end of passes, etc.
Another example involves selecting scheduler events + entry/exit of
a syscall, using the syscalls tracepoints, one can then see the
scheduler events that take place while that syscall is being processed.
In the future this should be possible in record/top/trace via eBPF
where the perf tools would hook into the marker events and enable events
put in place but not enabled when the on/off conditions are the desired
ones, reducing the amount of events sampled, but this userspace only
solution should be good enough for many scenarios.
perf vendor events intel:
Haiyan Song:
- Add Tremontx event file v1.02.
unwind:
John Keeping:
- Fix callchain unwinding when tid != pid, that was working only for the
thread group leader.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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commit e2736219e6ca3117e10651e215b96d66775220da
Author: John Keeping <john@metanate.com>
Date: Thu Aug 15 11:01:46 2019 +0100
perf unwind: Remove unnecessary test
If dwarf_callchain_users is false, then unwind__prepare_access() will
not set unwind_libunwind_ops so the remaining test here is sufficient.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: john keeping <john@metanate.com>
Link: http://lkml.kernel.org/r/20190815100146.28842-3-john@metanate.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index b843f9d0a9ea..6499b22b158b 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -69,18 +69,12 @@ int unwind__prepare_access(struct map_groups *mg, struct map *map,
void unwind__flush_access(struct map_groups *mg)
{
- if (!dwarf_callchain_users)
- return;
-
if (mg->unwind_libunwind_ops)
mg->unwind_libunwind_ops->flush_access(mg);
}
void unwind__finish_access(struct map_groups *mg)
{
- if (!dwarf_callchain_users)
- return;
-
if (mg->unwind_libunwind_ops)
mg->unwind_libunwind_ops->finish_access(mg);
}
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Merge tag 'perf-core-for-mingo-5.4-20190816' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo:
report/script/trace/top:
Arnaldo Carvalho de Melo:
- Allow specifying marker events demarcating when to consider the other events,
i.e. one now can state something like:
# perf probe kernel_function
# perf record -e cycles,probe:kernel_function
And then, in 'perf script' or 'perf report' say:
# perf report --switch-on=probe:kernel_function
And then the cycles event samples will be considered only after we
find the first probe:kernel_function event.
There is also --switch-off=event, to make it stop considering events
out of some window, say to avoid some winding down of a workload.
The same can be done with the "live mode" tools: 'perf top' and 'perf trace'.
There are examples in the cset comments showing how to use it with
SDT events in things like 'systemtap', that have those tracepoint-like
events for the start/end of passes, etc.
Another example involves selecting scheduler events + entry/exit of
a syscall, using the syscalls tracepoints, one can then see the
scheduler events that take place while that syscall is being processed.
In the future this should be possible in record/top/trace via eBPF
where the perf tools would hook into the marker events and enable events
put in place but not enabled when the on/off conditions are the desired
ones, reducing the amount of events sampled, but this userspace only
solution should be good enough for many scenarios.
perf vendor events intel:
Haiyan Song:
- Add Tremontx event file v1.02.
unwind:
John Keeping:
- Fix callchain unwinding when tid != pid, that was working only for the
thread group leader.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
-----BEGIN PGP SIGNATURE-----
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VXbpQ7byj339Wo7SpjadzLl9xPlh/Qw=
=IaYE
-----END PGP SIGNATURE-----
commit e2736219e6ca3117e10651e215b96d66775220da
Author: John Keeping <john@metanate.com>
Date: Thu Aug 15 11:01:46 2019 +0100
perf unwind: Remove unnecessary test
If dwarf_callchain_users is false, then unwind__prepare_access() will
not set unwind_libunwind_ops so the remaining test here is sufficient.
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: john keeping <john@metanate.com>
Link: http://lkml.kernel.org/r/20190815100146.28842-3-john@metanate.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index b843f9d0a9ea..6499b22b158b 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -69,18 +69,12 @@ int unwind__prepare_access(struct map_groups *mg, struct map *map,
void unwind__flush_access(struct map_groups *mg)
{
- if (!dwarf_callchain_users)
- return;
-
if (mg->unwind_libunwind_ops)
mg->unwind_libunwind_ops->flush_access(mg);
}
void unwind__finish_access(struct map_groups *mg)
{
- if (!dwarf_callchain_users)
- return;
-
if (mg->unwind_libunwind_ops)
mg->unwind_libunwind_ops->finish_access(mg);
}
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.