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authorIan Rogers <[email protected]>2025-01-13 19:43:45 +0000
committerNamhyung Kim <[email protected]>2025-02-13 04:06:11 +0000
commitdc6d2bc2d893a878e7b58578ff01b4738708deb4 (patch)
treeb5524ff4429f1e88533f518753091462bc4bd8b4 /tools/perf/tests/switch-tracking.c
parentperf test stat_all_metrics: Ensure missing events fail test (diff)
downloadkernel-dc6d2bc2d893a878e7b58578ff01b4738708deb4.tar.gz
kernel-dc6d2bc2d893a878e7b58578ff01b4738708deb4.zip
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 <[email protected]> as about 2.5% when running `perf script --itrace=i0`: https://lore.kernel.org/lkml/d841b97b3ad2ca8bcab07e4293375fb7c32dfce7.1736618095.git.tavianator@tavianator.com/ Adrian Hunter <[email protected]> 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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]>
Diffstat (limited to 'tools/perf/tests/switch-tracking.c')
-rw-r--r--tools/perf/tests/switch-tracking.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/tools/perf/tests/switch-tracking.c b/tools/perf/tests/switch-tracking.c
index 576f82a15015..8df3f9d9ffd2 100644
--- a/tools/perf/tests/switch-tracking.c
+++ b/tools/perf/tests/switch-tracking.c
@@ -131,9 +131,11 @@ static int process_sample_event(struct evlist *evlist,
pid_t next_tid, prev_tid;
int cpu, err;
+ perf_sample__init(&sample, /*all=*/false);
if (evlist__parse_sample(evlist, event, &sample)) {
pr_debug("evlist__parse_sample failed\n");
- return -1;
+ err = -1;
+ goto out;
}
evsel = evlist__id2evsel(evlist, sample.id);
@@ -145,7 +147,7 @@ static int process_sample_event(struct evlist *evlist,
cpu, prev_tid, next_tid);
err = check_cpu(switch_tracking, cpu);
if (err)
- return err;
+ goto out;
/*
* Check for no missing sched_switch events i.e. that the
* evsel->core.system_wide flag has worked.
@@ -153,7 +155,8 @@ static int process_sample_event(struct evlist *evlist,
if (switch_tracking->tids[cpu] != -1 &&
switch_tracking->tids[cpu] != prev_tid) {
pr_debug("Missing sched_switch events\n");
- return -1;
+ err = -1;
+ goto out;
}
switch_tracking->tids[cpu] = next_tid;
}
@@ -169,7 +172,10 @@ static int process_sample_event(struct evlist *evlist,
switch_tracking->cycles_after_comm_4 = 1;
}
- return 0;
+ err = 0;
+out:
+ perf_sample__exit(&sample);
+ return err;
}
static int process_event(struct evlist *evlist, union perf_event *event,