From f6e707156e1d5d150f288823987bee1ba0104c4c Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 17 Jan 2023 22:05:58 -0800 Subject: perf/core: Introduce perf_prepare_header() Factor out perf_prepare_header() so that it can call perf_prepare_sample() without a header if not needed. Also it checks the filtered_sample_type to avoid duplicate work when perf_prepare_sample() is called twice (or more). Suggested-by: Peter Zijlstr Signed-off-by: Namhyung Kim Signed-off-by: Ingo Molnar Tested-by: Jiri Olsa Acked-by: Jiri Olsa Acked-by: Song Liu Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20230118060559.615653-8-namhyung@kernel.org --- arch/s390/kernel/perf_cpum_sf.c | 3 ++- arch/x86/events/intel/ds.c | 3 ++- include/linux/perf_event.h | 16 +++++++++++++++- kernel/events/core.c | 38 ++++++++++++++++++++++++-------------- 4 files changed, 43 insertions(+), 17 deletions(-) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index ce886a03545a..ead6eea48be8 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -672,7 +672,8 @@ static void cpumsf_output_event_pid(struct perf_event *event, /* Protect callchain buffers, tasks */ rcu_read_lock(); - perf_prepare_sample(&header, data, event, regs); + perf_prepare_sample(data, event, regs); + perf_prepare_header(&header, data, event, regs); if (perf_output_begin(&handle, data, event, header.size)) goto out; diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index 07c8a2cdc3ee..183efa914b99 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -807,7 +807,8 @@ int intel_pmu_drain_bts_buffer(void) * the sample. */ rcu_read_lock(); - perf_prepare_sample(&header, &data, event, ®s); + perf_prepare_sample(&data, event, ®s); + perf_prepare_header(&header, &data, event, ®s); if (perf_output_begin(&handle, &data, event, header.size * (top - base - skip))) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 7db0e9cc2682..d5628a7b5eaa 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1250,6 +1250,17 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data, data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; } +static inline u32 perf_sample_data_size(struct perf_sample_data *data, + struct perf_event *event) +{ + u32 size = sizeof(struct perf_event_header); + + size += event->header_size + event->id_header_size; + size += data->dyn_size; + + return size; +} + /* * Clear all bitfields in the perf_branch_entry. * The to and from fields are not cleared because they are @@ -1271,7 +1282,10 @@ extern void perf_output_sample(struct perf_output_handle *handle, struct perf_event_header *header, struct perf_sample_data *data, struct perf_event *event); -extern void perf_prepare_sample(struct perf_event_header *header, +extern void perf_prepare_sample(struct perf_sample_data *data, + struct perf_event *event, + struct pt_regs *regs); +extern void perf_prepare_header(struct perf_event_header *header, struct perf_sample_data *data, struct perf_event *event, struct pt_regs *regs); diff --git a/kernel/events/core.c b/kernel/events/core.c index 47bfd9985813..4aa73edbaf4c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7568,20 +7568,13 @@ static __always_inline u64 __cond_set(u64 flags, u64 s, u64 d) return d * !!(flags & s); } -void perf_prepare_sample(struct perf_event_header *header, - struct perf_sample_data *data, +void perf_prepare_sample(struct perf_sample_data *data, struct perf_event *event, struct pt_regs *regs) { u64 sample_type = event->attr.sample_type; u64 filtered_sample_type; - header->type = PERF_RECORD_SAMPLE; - header->size = sizeof(*header) + event->header_size + event->id_header_size; - - header->misc = 0; - header->misc |= perf_misc_flags(regs); - /* * Add the sample flags that are dependent to others. And clear the * sample flags that have already been done by the PMU driver. @@ -7595,6 +7588,12 @@ void perf_prepare_sample(struct perf_event_header *header, PERF_SAMPLE_REGS_USER); filtered_sample_type &= ~data->sample_flags; + if (filtered_sample_type == 0) { + /* Make sure it has the correct data->type for output */ + data->type = event->attr.sample_type; + return; + } + __perf_event_header__init_id(data, event, filtered_sample_type); if (filtered_sample_type & PERF_SAMPLE_IP) { @@ -7646,9 +7645,10 @@ void perf_prepare_sample(struct perf_event_header *header, * up the rest of the sample size. */ u16 stack_size = event->attr.sample_stack_user; + u16 header_size = perf_sample_data_size(data, event); u16 size = sizeof(u64); - stack_size = perf_sample_ustack_size(stack_size, header->size, + stack_size = perf_sample_ustack_size(stack_size, header_size, data->regs_user.regs); /* @@ -7733,8 +7733,9 @@ void perf_prepare_sample(struct perf_event_header *header, if (filtered_sample_type & PERF_SAMPLE_AUX) { u64 size; + u16 header_size = perf_sample_data_size(data, event); - header->size += sizeof(u64); /* size */ + header_size += sizeof(u64); /* size */ /* * Given the 16bit nature of header::size, an AUX sample can @@ -7742,17 +7743,25 @@ void perf_prepare_sample(struct perf_event_header *header, * Make sure this doesn't happen by using up to U16_MAX bytes * per sample in total (rounded down to 8 byte boundary). */ - size = min_t(size_t, U16_MAX - header->size, + size = min_t(size_t, U16_MAX - header_size, event->attr.aux_sample_size); size = rounddown(size, 8); size = perf_prepare_sample_aux(event, data, size); - WARN_ON_ONCE(size + header->size > U16_MAX); + WARN_ON_ONCE(size + header_size > U16_MAX); data->dyn_size += size + sizeof(u64); /* size above */ data->sample_flags |= PERF_SAMPLE_AUX; } +} - header->size += data->dyn_size; +void perf_prepare_header(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_event *event, + struct pt_regs *regs) +{ + header->type = PERF_RECORD_SAMPLE; + header->size = perf_sample_data_size(data, event); + header->misc = perf_misc_flags(regs); /* * If you're adding more sample types here, you likely need to do @@ -7781,7 +7790,8 @@ __perf_event_output(struct perf_event *event, /* protect the callchain buffers */ rcu_read_lock(); - perf_prepare_sample(&header, data, event, regs); + perf_prepare_sample(data, event, regs); + perf_prepare_header(&header, data, event, regs); err = output_begin(&handle, data, event, header.size); if (err) -- cgit v1.2.3