2012-11-02 16:02:07

by Shan Wei

Subject: [PATCH v2 7/9] trace: use this_cpu_ptr per-cpu helper

From: Shan Wei <[email protected]>


Signed-off-by: Shan Wei <[email protected]>
---
kernel/trace/blktrace.c | 2 +-
kernel/trace/trace.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c0bd030..71259e2 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -147,7 +147,7 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
return;

local_irq_save(flags);
- buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
+ buf = this_cpu_ptr(bt->msg_data);
va_start(args, fmt);
n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
va_end(args);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 31e4f55..81ae35b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1513,7 +1513,7 @@ static char *get_trace_buf(void)
if (!percpu_buffer)
return NULL;

- buffer = per_cpu_ptr(percpu_buffer, smp_processor_id());
+ buffer = this_cpu_ptr(percpu_buffer);

return buffer->buffer;
}
-- 1.7.1

2012-11-02 17:47:36

by Christoph Lameter (Ampere)

Subject: Re: [PATCH v2 7/9] trace: use this_cpu_ptr per-cpu helper

On Sat, 3 Nov 2012, Shan Wei wrote:

> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 31e4f55..81ae35b 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -1513,7 +1513,7 @@ static char *get_trace_buf(void)
> if (!percpu_buffer)
> return NULL;
>
> - buffer = per_cpu_ptr(percpu_buffer, smp_processor_id());
> + buffer = this_cpu_ptr(percpu_buffer);
>
> return buffer->buffer;

return this_cpu_read(percpu_buffer->buffer)

and drop the this_cpu_ptr operation please.