[PATCH] blktrace: Remove blk_fill_rwbs_rq.

From: Tao Ma
Date: Thu Mar 03 2011 - 02:30:12 EST


From: Tao Ma <boyu.mt@xxxxxxxxxx>

If we enable trace events to trace block actions, We use
blk_fill_rwbs_rq to analyze the corresponding actions
in request's cmd_flags, but we only choose the minor 2 bits
from it, so most of other flags(e.g, REQ_SYNC) are missing.
For example, with a sync write we get:
write_test-2409 [001] 160.013869: block_rq_insert: 3,64 W 0 () 258135 + 8 [write_test]

Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and
blk_fill_rwbs_rq isn't needed any more.

With this patch, after a sync write we get:
write_test-2417 [000] 226.603878: block_rq_insert: 3,64 WS 0 () 258135 + 8 [write_test]

Cc: Jens Axboe <jaxboe@xxxxxxxxxxxx>
Signed-off-by: Tao Ma <boyu.mt@xxxxxxxxxx>
---
include/linux/blktrace_api.h | 1 -
include/trace/events/block.h | 6 +++---
kernel/trace/blktrace.c | 16 ----------------
3 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 3395cf7..b22fb0d 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -245,7 +245,6 @@ static inline int blk_cmd_buf_len(struct request *rq)

extern void blk_dump_cmd(char *buf, struct request *rq);
extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
-extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);

#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index aba421d..78f18ad 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -31,7 +31,7 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
0 : blk_rq_sectors(rq);
__entry->errors = rq->errors;

- blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
blk_dump_cmd(__get_str(cmd), rq);
),

@@ -118,7 +118,7 @@ DECLARE_EVENT_CLASS(block_rq,
__entry->bytes = (rq->cmd_type == REQ_TYPE_BLOCK_PC) ?
blk_rq_bytes(rq) : 0;

- blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
blk_dump_cmd(__get_str(cmd), rq);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),
@@ -563,7 +563,7 @@ TRACE_EVENT(block_rq_remap,
__entry->nr_sector = blk_rq_sectors(rq);
__entry->old_dev = dev;
__entry->old_sector = from;
- blk_fill_rwbs_rq(__entry->rwbs, rq);
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
),

TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 07f4382..cfc059d 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1824,21 +1824,5 @@ void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
rwbs[i] = '\0';
}

-void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
-{
- int rw = rq->cmd_flags & 0x03;
- int bytes;
-
- if (rq->cmd_flags & REQ_DISCARD)
- rw |= REQ_DISCARD;
-
- if (rq->cmd_flags & REQ_SECURE)
- rw |= REQ_SECURE;
-
- bytes = blk_rq_bytes(rq);
-
- blk_fill_rwbs(rwbs, rw, bytes);
-}
-
#endif /* CONFIG_EVENT_TRACING */

--
1.6.3.GIT

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