Messages in this thread Patch in this message | | | Date | Tue, 16 Jul 2013 17:09:07 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH V5 09/12] perf: make events stream always parsable |
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On Tue, Jul 16, 2013 at 09:49:31AM +0300, Adrian Hunter wrote:
> If you want the ID at the first position in the ID sample, it is do-able. > It means perf tools will have to be changed to calculate the variable start > position of the ID sample, and then parse the ID sample forwards from there. > Please advise.
Oh urgh I see.. how about I merge something like the below first?
Re-reading your patch; you add something to struct sample_id; which means that events which 'forget' to set perf_event_attr::sample_id_all while setting PERF_SAMPLE_IDENTIFIER are 'funny'. Should we refuse them?
--- Subject: perf: Update perf_event_type documentation
Due to a discussion with Adrian I had a good look at the perf_event_type record layout and found the documentation to be somewhat unclear.
Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> --- include/uapi/linux/perf_event.h | 21 +++++++++++++++++++-- kernel/events/core.c | 31 ++++++++++++++++--------------- 2 files changed, 35 insertions(+), 17 deletions(-)
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 0b1df41..335016c 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -478,6 +478,16 @@ enum perf_event_type { * file will be supported by older perf tools, with these new optional * fields being ignored. * + * struct sample_id { + * { u32 pid, tid; } && PERF_SAMPLE_TID + * { u64 time; } && PERF_SAMPLE_TIME + * { u64 id; } && PERF_SAMPLE_ID + * { u64 stream_id;} && PERF_SAMPLE_STREAM_ID + * { u32 cpu, res; } && PERF_SAMPLE_CPU + * } && perf_event_attr::sample_id_all + */ + + /* * The MMAP events record the PROT_EXEC mappings so that we can * correlate userspace IPs to code. They have the following structure: * @@ -488,7 +498,8 @@ enum perf_event_type { * u64 addr; * u64 len; * u64 pgoff; + * struct sample_id sample_id; * }; */ PERF_RECORD_MMAP = 1, @@ -498,6 +509,7 @@ enum perf_event_type { * struct perf_event_header header; * u64 id; * u64 lost; + * struct sample_id sample_id; * }; */ PERF_RECORD_LOST = 2, @@ -508,6 +520,7 @@ enum perf_event_type { * * u32 pid, tid; * char comm[]; + * struct sample_id sample_id; * }; */ PERF_RECORD_COMM = 3, @@ -518,6 +531,7 @@ enum perf_event_type { * u32 pid, ppid; * u32 tid, ptid; * u64 time; + * struct sample_id sample_id; * }; */ PERF_RECORD_EXIT = 4, @@ -528,6 +542,7 @@ enum perf_event_type { * u64 time; * u64 id; * u64 stream_id; + * struct sample_id sample_id; * }; */ PERF_RECORD_THROTTLE = 5, @@ -539,6 +554,7 @@ enum perf_event_type { * u32 pid, ppid; * u32 tid, ptid; * u64 time; + * struct sample_id sample_id; * }; */ PERF_RECORD_FORK = 7, @@ -549,6 +565,7 @@ enum perf_event_type { * u32 pid, tid; * * struct read_format values; + * struct sample_id sample_id; * }; */ PERF_RECORD_READ = 8, @@ -596,7 +613,7 @@ enum perf_event_type { * u64 dyn_size; } && PERF_SAMPLE_STACK_USER * * { u64 weight; } && PERF_SAMPLE_WEIGHT - * { u64 data_src; } && PERF_SAMPLE_DATA_SRC + * { u64 data_src; } && PERF_SAMPLE_DATA_SRC * }; */ PERF_RECORD_SAMPLE = 9, diff --git a/kernel/events/core.c b/kernel/events/core.c index 708ab70..c9ef899 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4462,20 +4462,6 @@ void perf_output_sample(struct perf_output_handle *handle, } } - if (!event->attr.watermark) { - int wakeup_events = event->attr.wakeup_events; - - if (wakeup_events) { - struct ring_buffer *rb = handle->rb; - int events = local_inc_return(&rb->events); - - if (events >= wakeup_events) { - local_sub(wakeup_events, &rb->events); - local_inc(&rb->wakeup); - } - } - } - if (sample_type & PERF_SAMPLE_BRANCH_STACK) { if (data->br_stack) { size_t size; @@ -4511,16 +4497,31 @@ void perf_output_sample(struct perf_output_handle *handle, } } - if (sample_type & PERF_SAMPLE_STACK_USER) + if (sample_type & PERF_SAMPLE_STACK_USER) { perf_output_sample_ustack(handle, data->stack_user_size, data->regs_user.regs); + } if (sample_type & PERF_SAMPLE_WEIGHT) perf_output_put(handle, data->weight); if (sample_type & PERF_SAMPLE_DATA_SRC) perf_output_put(handle, data->data_src.val); + + if (!event->attr.watermark) { + int wakeup_events = event->attr.wakeup_events; + + if (wakeup_events) { + struct ring_buffer *rb = handle->rb; + int events = local_inc_return(&rb->events); + + if (events >= wakeup_events) { + local_sub(wakeup_events, &rb->events); + local_inc(&rb->wakeup); + } + } + } } void perf_prepare_sample(struct perf_event_header *header,
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