From: Peter Zijlstra <pet...@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 <pet...@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 fb6f0a5..40eb07d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4441,8 +4441,11 @@ 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
