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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2017-03-30 18:39:56 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-29 16:09:24 +0300 |
| commit | 8d4e6c4caa12dafbcba138e5450b7af17b0b2194 (patch) | |
| tree | a9b6c4f3076bd27f9a87fb67a2907c9a0a3c5cbd /include | |
| parent | e0563e049531973e665db853e825a4efed9f881d (diff) | |
| download | linux-8d4e6c4caa12dafbcba138e5450b7af17b0b2194.tar.xz | |
perf/core, pt, bts: Get rid of itrace_started
I just noticed that hw.itrace_started and hw.config are aliased to the
same location. Now, the PT driver happens to use both, which works out
fine by sheer luck:
- STORE(hw.itrace_start) is ordered before STORE(hw.config), in the
program order, although there are no compiler barriers to ensure that,
- to the perf_log_itrace_start() hw.itrace_start looks set at the same
time as when it is intended to be set because both stores happen in the
same path,
- hw.config is never reset to zero in the PT driver.
Now, the use of hw.config by the PT driver makes more sense (it being a
HW PMU) than messing around with itrace_started, which is an awkward API
to begin with.
This patch replaces hw.itrace_started with an attach_state bit and an
API call for the PMU drivers to use to communicate the condition.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170330153956.25994-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/perf_event.h | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index c00cd4b02f32..adda0aaae6c8 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -147,9 +147,6 @@ struct hw_perf_event { struct list_head cqm_groups_entry; struct list_head cqm_group_entry; }; - struct { /* itrace */ - int itrace_started; - }; struct { /* amd_power */ u64 pwr_acc; u64 ptsc; @@ -541,6 +538,7 @@ struct swevent_hlist { #define PERF_ATTACH_GROUP 0x02 #define PERF_ATTACH_TASK 0x04 #define PERF_ATTACH_TASK_DATA 0x08 +#define PERF_ATTACH_ITRACE 0x10 struct perf_cgroup; struct ring_buffer; @@ -864,6 +862,7 @@ extern int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size); extern void *perf_get_aux(struct perf_output_handle *handle); extern void perf_aux_output_flag(struct perf_output_handle *handle, u64 flags); +extern void perf_event_itrace_started(struct perf_event *event); extern int perf_pmu_register(struct pmu *pmu, const char *name, int type); extern void perf_pmu_unregister(struct pmu *pmu); |