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perf: Improve the perf_sample_data struct layout

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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 (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1411559322-16548-7-git-send-email-eranian@google.com
Cc: cebbert.lkml@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: jolsa@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2014-09-24 13:48:42 +02:00 committed by Ingo Molnar
parent 4b6c51773d
commit 2565711fb7
2 changed files with 25 additions and 25 deletions
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34
include/linux/perf_event.h
View File

@ -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,

16
kernel/events/core.c
View File

@ -4471,8 +4471,11 @@ 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;
}
}
@ -4947,12 +4950,13 @@ void perf_prepare_sample(struct perf_event_header *header,
header->size += size;
}
if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
perf_sample_regs_user(&data->regs_user, regs);
if (sample_type & PERF_SAMPLE_REGS_USER) {
/* regs dump ABI info */
int size = sizeof(u64);
perf_sample_regs_user(&data->regs_user, regs);
if (data->regs_user.regs) {
u64 mask = event->attr.sample_regs_user;
size += hweight64(mask) * sizeof(u64);
@ -4968,15 +4972,11 @@ void perf_prepare_sample(struct perf_event_header *header,
* in case new sample type is added, because we could eat
* up the rest of the sample size.
*/
struct perf_regs *uregs = &data->regs_user;
u16 stack_size = event->attr.sample_stack_user;
u16 size = sizeof(u64);
if (!uregs->abi)
perf_sample_regs_user(uregs, regs);
stack_size = perf_sample_ustack_size(stack_size, header->size,
uregs->regs);
data->regs_user.regs);
/*
* If there is something to dump, add space for the dump