From: Shan Wei <davids...@tencent.com>
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.
Signed-off-by: Shan Wei <davids...@tencent.com>
---
v4: avoid type cast using &percpu_buffer->buffer[0].
---
kernel/trace/blktrace.c | 2 +-
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 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..65cb003 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1495,7 +1495,6 @@ 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
@@ -1513,9 +1512,7 @@ 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)
--
1.7.1
--
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