Messages in this thread | | | Date | Thu, 3 Mar 2016 09:21:30 +0100 | From | Ingo Molnar <> | Subject | Re: [GIT PULL 00/11] perf/core improvements and fixes |
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* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Hi Ingo, > > Please consider pulling, > > - Arnaldo > > The following changes since commit 675965b00d734c985e4285f5bec7e524d15fc4e1: > > perf: Export perf_event_sysfs_show() (2016-02-29 09:35:27 +0100) > > are available in the git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-core-for-mingo-20160229 > > for you to fetch changes up to 575a02e00b11eecbbabcb1eb22eab4c68e91ae77: > > perf record: Ensure return non-zero rc when mmap fail (2016-02-29 12:44:15 -0300) > > ---------------------------------------------------------------- > perf/core improvements and fixes: > > User visible: > > - Check existence of frontend/backed stalled cycles in 'perf stat' (Andi Kleen) > > - Avoid installing .o files from tools/lib/ into the python extension (Jiri Olsa) > > - Rename the tracepoint '/format' field that carries the syscall ID from 'nr', > that is also the name of some syscalls arguments, to "__syscall_nr", to > avoid having multiple fields with the same name, that was breaking the > python script skeleton generator from perf.data files (Taeung Song) > > - Support converting data from bpf events in 'perf data' (Wang Nan) > > Infrastructure: > > - Split libtraceevent's pevent_print_event() (Steven Rostedt) > > - Librarize some 'perf record' bits to allow handling multiple perf.data > files per session (Wang Nan) > > - Ensure return non-zero rc when mmap fail in 'perf record' (Wang Nan) > > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > > ---------------------------------------------------------------- > Andi Kleen (1): > perf stat: Check existence of frontend/backed stalled cycles
> > Jiri Olsa (1): > perf tools: Fix python extension build > > Steven Rostedt (1): > tools lib traceevent: Split pevent_print_event() into specific functionality functions > > Taeung Song (2): > perf trace: Check and discard not only 'nr' but also '__syscall_nr' > tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr: > > Wang Nan (6): > perf data: Support converting data from bpf_perf_event_output() > perf data: Explicitly set byte order for integer types > perf record: Use WARN_ONCE to replace 'if' condition > perf record: Extract synthesize code to record__synthesize() > perf record: Introduce record__finish_output() to finish a perf.data > perf record: Ensure return non-zero rc when mmap fail > > kernel/trace/trace_syscalls.c | 16 ++-- > tools/lib/traceevent/event-parse.c | 136 +++++++++++++++++++++++------- > tools/lib/traceevent/event-parse.h | 13 +++ > tools/perf/builtin-record.c | 168 ++++++++++++++++++++++--------------- > tools/perf/builtin-stat.c | 22 ++++- > tools/perf/builtin-trace.c | 8 +- > tools/perf/util/data-convert-bt.c | 118 +++++++++++++++++++++++++- > tools/perf/util/setup.py | 4 + > 8 files changed, 372 insertions(+), 113 deletions(-)
Hm, there's a 'perf stat' regression that I can see:
Before:
triton:~/tip> perf stat -a sleep 1
Performance counter stats for 'system wide':
11990.023100 task-clock (msec) # 11.981 CPUs utilized 8,802 context-switches # 0.734 K/sec 543 cpu-migrations # 0.045 K/sec 97,375 page-faults # 0.008 M/sec 9,854,385,894 cycles # 0.822 GHz 15,274,841,152 stalled-cycles-frontend # 155.01% frontend cycles idle <not supported> stalled-cycles-backend 9,634,486,137 instructions # 0.98 insn per cycle # 1.59 stalled cycles per insn 1,818,488,088 branches # 151.667 M/sec 46,365,120 branch-misses # 2.55% of all branches
1.000741599 seconds time elapsed
After:
triton:~/tip> perf stat -a sleep 1
Performance counter stats for 'system wide':
11989.280397 task-clock (msec) # 11.981 CPUs utilized 1299 context-switches # 0.108 K/sec 6 cpu-migrations # 0.001 K/sec 70 page-faults # 0.006 K/sec 127008602 cycles # 0.011 GHz 279538533 stalled-cycles-frontend # 220.09% frontend cycles idle 119213269 instructions # 0.94 insn per cycle # 2.34 stalled cycles per insn 24166678 branches # 2.016 M/sec 505681 branch-misses # 2.09% of all branches
1.000684278 seconds time elapsed
... see how the numbers became human-unreadable, losing the big-number separator?
I suspect it's due to the following commit:
fa184776ac27 perf stat: Check existence of frontend/backed stalled cycles
Thanks,
Ingo
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