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07dc3a6de3
bperf has a nice ability to share PMUs, but it still does not support
inherit events during fork(), resulting in some deviations in its stat
results compared with perf.
perf stat result:
$ ./perf stat -e cycles,instructions -- ./perf test -w sqrtloop
Performance counter stats for './perf test -w sqrtloop':
2,316,038,116 cycles
2,859,350,725 instructions
1.009603637 seconds time elapsed
1.004196000 seconds user
0.003950000 seconds sys
bperf stat result:
$ ./perf stat --bpf-counters -e cycles,instructions -- \
./perf test -w sqrtloop
Performance counter stats for './perf test -w sqrtloop':
18,762,093 cycles
23,487,766 instructions
1.008913769 seconds time elapsed
1.003248000 seconds user
0.004069000 seconds sys
In order to support event inheritance, two new bpf programs are added
to monitor the fork and exit of tasks respectively. When a task is
created, add it to the filter map to enable counting, and reuse the
`accum_key` of its parent task to count together with the parent task.
When a task exits, remove it from the filter map to disable counting.
After support:
$ ./perf stat --bpf-counters -e cycles,instructions -- \
./perf test -w sqrtloop
Performance counter stats for './perf test -w sqrtloop':
2,316,252,189 cycles
2,859,946,547 instructions
1.009422314 seconds time elapsed
1.003597000 seconds user
0.004270000 seconds sys
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Cc: song@kernel.org
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20241021110201.325617-2-wutengda@huaweicloud.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PERF_TARGET_H
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#define _PERF_TARGET_H
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#include <stdbool.h>
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#include <sys/types.h>
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struct target {
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const char *pid;
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const char *tid;
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const char *cpu_list;
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const char *uid_str;
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const char *bpf_str;
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uid_t uid;
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bool system_wide;
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bool uses_mmap;
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bool default_per_cpu;
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bool per_thread;
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bool use_bpf;
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bool inherit;
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int initial_delay;
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const char *attr_map;
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};
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enum target_errno {
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TARGET_ERRNO__SUCCESS = 0,
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/*
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* Choose an arbitrary negative big number not to clash with standard
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* errno since SUS requires the errno has distinct positive values.
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* See 'Issue 6' in the link below.
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*
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* http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
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*/
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__TARGET_ERRNO__START = -10000,
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/* for target__validate() */
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TARGET_ERRNO__PID_OVERRIDE_CPU = __TARGET_ERRNO__START,
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TARGET_ERRNO__PID_OVERRIDE_UID,
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TARGET_ERRNO__UID_OVERRIDE_CPU,
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TARGET_ERRNO__PID_OVERRIDE_SYSTEM,
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TARGET_ERRNO__UID_OVERRIDE_SYSTEM,
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TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD,
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TARGET_ERRNO__BPF_OVERRIDE_CPU,
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TARGET_ERRNO__BPF_OVERRIDE_PID,
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TARGET_ERRNO__BPF_OVERRIDE_UID,
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TARGET_ERRNO__BPF_OVERRIDE_THREAD,
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/* for target__parse_uid() */
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TARGET_ERRNO__INVALID_UID,
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TARGET_ERRNO__USER_NOT_FOUND,
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__TARGET_ERRNO__END,
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};
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enum target_errno target__validate(struct target *target);
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enum target_errno target__parse_uid(struct target *target);
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int target__strerror(struct target *target, int errnum, char *buf, size_t buflen);
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static inline bool target__has_task(struct target *target)
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{
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return target->tid || target->pid || target->uid_str;
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}
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static inline bool target__has_cpu(struct target *target)
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{
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return target->system_wide || target->cpu_list;
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}
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static inline bool target__none(struct target *target)
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{
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return !target__has_task(target) && !target__has_cpu(target);
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}
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static inline bool target__enable_on_exec(struct target *target)
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{
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/*
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* Normally enable_on_exec should be set if:
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* 1) The tracee process is forked (not attaching to existed task or cpu).
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* 2) And initial_delay is not configured.
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* Otherwise, we enable tracee events manually.
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*/
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return target__none(target) && !target->initial_delay;
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}
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static inline bool target__has_per_thread(struct target *target)
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{
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return target->system_wide && target->per_thread;
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}
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static inline bool target__uses_dummy_map(struct target *target)
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{
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bool use_dummy = false;
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if (target->default_per_cpu)
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use_dummy = target->per_thread ? true : false;
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else if (target__has_task(target) ||
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(!target__has_cpu(target) && !target->uses_mmap))
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use_dummy = true;
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else if (target__has_per_thread(target))
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use_dummy = true;
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return use_dummy;
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}
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#endif /* _PERF_TARGET_H */
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