From 64565911cdb57c2f512a9715b985b5617402cc67 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 28 May 2008 14:45:33 +0200 Subject: block: make blktrace use per-cpu buffers for message notes Currently it uses a single static char array, but that risks being corrupted when multiple users issue message notes at the same time. Make the buffers dynamically allocated when the trace is setup and make them per-cpu instead. The default max message size of 1k is also very large, the interface is mainly for small text notes. So shrink it to 128 bytes. Signed-off-by: Jens Axboe --- include/linux/blktrace_api.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index b7cd8f1eedb..e3ef903aae8 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -121,6 +121,7 @@ struct blk_trace { int trace_state; struct rchan *rchan; unsigned long *sequence; + unsigned char *msg_data; u16 act_mask; u64 start_lba; u64 end_lba; @@ -172,7 +173,7 @@ extern void __trace_note_message(struct blk_trace *, const char *fmt, ...); if (unlikely(bt)) \ __trace_note_message(bt, fmt, ##__VA_ARGS__); \ } while (0) -#define BLK_TN_MAX_MSG 1024 +#define BLK_TN_MAX_MSG 128 /** * blk_add_trace_rq - Add a trace for a request oriented action -- cgit v1.2.3-18-g5258