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authorPeter Zijlstra2014-09-24 13:48:42 +0200
committerIngo Molnar2014-11-16 11:42:04 +0100
commit2565711fb7d7c28e0cd93c8971b520d1b10b857c (patch)
treeace1ace82ecd5f2490b65a20df5b1d781d8a62c3 /kernel
parent4b6c51773d86883a2e80cffadbe4f178ac1babd8 (diff)
perf: Improve the perf_sample_data struct layout
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c2be1597ece7..3e19d3ebc29c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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