Messages in this thread Patch in this message | | | From | Stephane Eranian <> | Subject | [PATCH v4 6/6] perf: improve perf_sample_data struct layout | Date | Wed, 3 Sep 2014 16:59:11 +0200 |
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From: Peter Zijlstra <peterz@infradead.org>
This patch reorders fields in the perf_sample_data struct in order to minimize the number of cachelines touched in perf_sample_data_init(). It also removes some intializations which are redundant with the code in kernel/events/core.c
Signed-off-by: Peter Zijlstra <peterz@infradead.org> --- include/linux/perf_event.h | 34 +++++++++++++++++----------------- kernel/events/core.c | 5 ++++- 2 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 68d46d5..486e84c 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -580,35 +580,40 @@ extern u64 perf_event_read_value(struct perf_event *event, struct perf_sample_data { - u64 type; + /* + * Fields set by perf_sample_data_init(), group so as to + * minimize the cachelines touched. + */ + u64 addr; + struct perf_raw_record *raw; + struct perf_branch_stack *br_stack; + u64 period; + u64 weight; + u64 txn; + union perf_mem_data_src data_src; + /* + * The other fields, optionally {set,used} by + * perf_{prepare,output}_sample(). + */ + u64 type; u64 ip; struct { u32 pid; u32 tid; } tid_entry; u64 time; - u64 addr; u64 id; u64 stream_id; struct { u32 cpu; u32 reserved; } cpu_entry; - u64 period; - union perf_mem_data_src data_src; struct perf_callchain_entry *callchain; - struct perf_raw_record *raw; - struct perf_branch_stack *br_stack; struct perf_regs regs_user; struct perf_regs regs_intr; u64 stack_user_size; - u64 weight; - /* - * Transaction flags for abort events: - */ - u64 txn; -}; +} ____cacheline_aligned; /* default value for data source */ #define PERF_MEM_NA (PERF_MEM_S(OP, NA) |\ @@ -625,14 +630,9 @@ static inline void perf_sample_data_init(struct perf_sample_data *data, data->raw = NULL; data->br_stack = NULL; data->period = period; - data->regs_user.abi = PERF_SAMPLE_REGS_ABI_NONE; - data->regs_user.regs = NULL; - data->stack_user_size = 0; data->weight = 0; data->data_src.val = PERF_MEM_NA; data->txn = 0; - data->regs_intr.abi = PERF_SAMPLE_REGS_ABI_NONE; - data->regs_intr.regs = NULL; } extern void perf_output_sample(struct perf_output_handle *handle, diff --git a/kernel/events/core.c b/kernel/events/core.c index 7459b02..575869d 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4432,8 +4432,11 @@ static void perf_sample_regs_user(struct perf_regs *regs_user, } if (regs) { - regs_user->regs = regs; regs_user->abi = perf_reg_abi(current); + regs_user->regs = regs; + } else { + regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE; + regs_user->regs = NULL; } } -- 1.7.9.5
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