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| author | Alexei Starovoitov <ast@fb.com> | 2016-04-06 18:43:24 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-07 21:04:26 -0400 |
| commit | 1e1dcd93b468901e114f279c94a0b356adc5e7cd (patch) | |
| tree | b0bee9a35251caacc44d9a3ffbbae90e8afb237d /kernel/trace/trace_kprobe.c | |
| parent | e93735be6a1898dd9f8de8f55254cc76309777ce (diff) | |
| download | lwn-1e1dcd93b468901e114f279c94a0b356adc5e7cd.tar.gz lwn-1e1dcd93b468901e114f279c94a0b356adc5e7cd.zip | |
perf: split perf_trace_buf_prepare into alloc and update parts
split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.
While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 919e0ddd8fcc..5546eec0505f 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1149,14 +1149,15 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); + entry = perf_trace_buf_alloc(size, NULL, &rctx); if (!entry) return; entry->ip = (unsigned long)tk->rp.kp.addr; memset(&entry[1], 0, dsize); store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); - perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, + head, NULL); } NOKPROBE_SYMBOL(kprobe_perf_func); @@ -1184,14 +1185,15 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, size = ALIGN(__size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); + entry = perf_trace_buf_alloc(size, NULL, &rctx); if (!entry) return; entry->func = (unsigned long)tk->rp.kp.addr; entry->ret_ip = (unsigned long)ri->ret_addr; store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); - perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); + perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, + head, NULL); } NOKPROBE_SYMBOL(kretprobe_perf_func); #endif /* CONFIG_PERF_EVENTS */ |