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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>
113 lines
2.6 KiB
C
113 lines
2.6 KiB
C
#include <linux/kernel.h>
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#include <linux/types.h>
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#include <stddef.h>
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#include "tests.h"
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#include "event.h"
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#include "evlist.h"
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#include "header.h"
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#include "debug.h"
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#include "util/sample.h"
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static int process_event(struct evlist **pevlist, union perf_event *event)
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{
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struct perf_sample sample;
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int ret;
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if (event->header.type == PERF_RECORD_HEADER_ATTR) {
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if (perf_event__process_attr(NULL, event, pevlist)) {
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pr_debug("perf_event__process_attr failed\n");
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return -1;
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}
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return 0;
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}
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if (event->header.type >= PERF_RECORD_USER_TYPE_START)
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return -1;
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if (!*pevlist)
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return -1;
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perf_sample__init(&sample, /*all=*/false);
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ret = evlist__parse_sample(*pevlist, event, &sample);
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perf_sample__exit(&sample);
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if (ret) {
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pr_debug("evlist__parse_sample failed\n");
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return -1;
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}
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return 0;
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}
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static int process_events(union perf_event **events, size_t count)
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{
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struct evlist *evlist = NULL;
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int err = 0;
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size_t i;
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for (i = 0; i < count && !err; i++)
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err = process_event(&evlist, events[i]);
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evlist__delete(evlist);
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return err;
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}
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struct test_attr_event {
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struct perf_event_header header;
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struct perf_event_attr attr;
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u64 id;
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};
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/**
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* test__parse_no_sample_id_all - test parsing with no sample_id_all bit set.
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*
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* This function tests parsing data produced on kernel's that do not support the
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* sample_id_all bit. Without the sample_id_all bit, non-sample events (such as
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* mmap events) do not have an id sample appended, and consequently logic
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* designed to determine the id will not work. That case happens when there is
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* more than one selected event, so this test processes three events: 2
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* attributes representing the selected events and one mmap event.
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*
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* Return: %0 on success, %-1 if the test fails.
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*/
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static int test__parse_no_sample_id_all(struct test_suite *test __maybe_unused,
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int subtest __maybe_unused)
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{
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int err;
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struct test_attr_event event1 = {
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.header = {
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.type = PERF_RECORD_HEADER_ATTR,
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.size = sizeof(struct test_attr_event),
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},
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.id = 1,
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};
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struct test_attr_event event2 = {
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.header = {
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.type = PERF_RECORD_HEADER_ATTR,
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.size = sizeof(struct test_attr_event),
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},
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.id = 2,
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};
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struct perf_record_mmap event3 = {
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.header = {
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.type = PERF_RECORD_MMAP,
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.size = sizeof(struct perf_record_mmap),
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},
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};
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union perf_event *events[] = {
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(union perf_event *)&event1,
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(union perf_event *)&event2,
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(union perf_event *)&event3,
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};
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err = process_events(events, ARRAY_SIZE(events));
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if (err)
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return -1;
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return 0;
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}
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DEFINE_SUITE("Parse with no sample_id_all bit set", parse_no_sample_id_all);
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