diff options
| author | Ian Rogers <irogers@google.com> | 2025-01-13 11:43:45 -0800 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-02-12 20:06:11 -0800 |
| commit | dc6d2bc2d893a878e7b58578ff01b4738708deb4 (patch) | |
| tree | b5524ff4429f1e88533f518753091462bc4bd8b4 /tools/perf/util/s390-cpumsf.c | |
| parent | 08d9e883481b2c38326ed37314b1f6a1284c03d8 (diff) | |
perf sample: Make user_regs and intr_regs optional
The struct dump_regs contains 512 bytes of cache_regs, meaning the two
values in perf_sample contribute 1088 bytes of its total 1384 bytes
size. Initializing this much memory has a cost reported by Tavian
Barnes <tavianator@tavianator.com> as about 2.5% when running `perf
script --itrace=i0`:
https://lore.kernel.org/lkml/d841b97b3ad2ca8bcab07e4293375fb7c32dfce7.1736618095.git.tavianator@tavianator.com/
Adrian Hunter <adrian.hunter@intel.com> replied that the zero
initialization was necessary and couldn't simply be removed.
This patch aims to strike a middle ground of still zeroing the
perf_sample, but removing 79% of its size by make user_regs and
intr_regs optional pointers to zalloc-ed memory. To support the
allocation accessors are created for user_regs and intr_regs. To
support correct cleanup perf_sample__init and perf_sample__exit
functions are created and added throughout the code base.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250113194345.1537821-1-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools/perf/util/s390-cpumsf.c')
| -rw-r--r-- | tools/perf/util/s390-cpumsf.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/tools/perf/util/s390-cpumsf.c b/tools/perf/util/s390-cpumsf.c index 30638653ad2d..0ce52f0280b8 100644 --- a/tools/perf/util/s390-cpumsf.c +++ b/tools/perf/util/s390-cpumsf.c @@ -513,6 +513,7 @@ static bool s390_cpumsf_make_event(size_t pos, .period = 1 }; union perf_event event; + int ret; memset(&event, 0, sizeof(event)); if (basic->CL == 1) /* Native LPAR mode */ @@ -536,8 +537,9 @@ static bool s390_cpumsf_make_event(size_t pos, pr_debug4("%s pos:%#zx ip:%#" PRIx64 " P:%d CL:%d pid:%d.%d cpumode:%d cpu:%d\n", __func__, pos, sample.ip, basic->P, basic->CL, sample.pid, sample.tid, sample.cpumode, sample.cpu); - if (perf_session__deliver_synth_event(sfq->sf->session, &event, - &sample)) { + ret = perf_session__deliver_synth_event(sfq->sf->session, &event, &sample); + perf_sample__exit(&sample); + if (ret) { pr_err("s390 Auxiliary Trace: failed to deliver event\n"); return false; } |