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| author |   Shan Wei <davidshan@tencent.com> | 2012-11-13 09:53:04 +0800 |
|---|---|---|
| committer |   Steven Rostedt <rostedt@goodmis.org> | 2013-01-21 13:22:30 -0500 |
| commit | d8a0349c0cea477322c66ea9362f10c62fad5f62 (patch) | |
| tree | ca9bd84c3629bc166f407c34055eb809e416d430 /kernel/trace | |
| parent | ring-buffer: Remove unnecessary recusive call in rb_advance_iter() (diff) | |
| download | linux-dev-d8a0349c0cea477322c66ea9362f10c62fad5f62.tar.xz linux-dev-d8a0349c0cea477322c66ea9362f10c62fad5f62.zip | |
tracing: Use this_cpu_ptr per-cpu helper
typeof(&buffer) is a pointer to array of 1024 char, or char (*)[1024].
But, typeof(&buffer[0]) is a pointer to char which match the return type of get_trace_buf().
As well-known, the value of &buffer is equal to &buffer[0].
so return this_cpu_ptr(&percpu_buffer->buffer[0]) can avoid type cast.
Link: http://lkml.kernel.org/r/50A1A800.3020102@gmail.com
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/blktrace.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 5 |
2 files changed, 2 insertions, 5 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index c0bd0308741c..71259e2b6b61 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 3c13e46d7d24..f8b7c626f3fd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1517,7 +1517,6 @@ static struct trace_buffer_struct *trace_percpu_nmi_buffer; static char *get_trace_buf(void) { struct trace_buffer_struct *percpu_buffer; - struct trace_buffer_struct *buffer; /* * If we have allocated per cpu buffers, then we do not @@ -1535,9 +1534,7 @@ static char *get_trace_buf(void) if (!percpu_buffer) return NULL; - buffer = per_cpu_ptr(percpu_buffer, smp_processor_id()); - - return buffer->buffer; + return this_cpu_ptr(&percpu_buffer->buffer[0]); } static int alloc_percpu_trace_buffer(void) |