On 16/07/13 18:09, Peter Zijlstra wrote: > 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?
I put in my V7 series. > > 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? No, that is OK. > > > --- > 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 <[email protected]> > Signed-off-by: Peter Zijlstra <[email protected]> > --- > 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, > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
