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authorNathan Scott <nathans@sgi.com>2006-07-06 10:03:28 +0200
committerJens Axboe <axboe@suse.de>2006-07-06 10:03:28 +0200
commit40359ccb836866435b03a0cb57345002b587d875 (patch)
tree4e0530a7759ba9802658901432a89683fbb0965d
parentfc0a75ce4835187a3f76d6b35f0644d1b168eef5 (diff)
[PATCH] blktrace: readahead support
Provide the needed kernel support for distinguishing readahead from regular read requests when tracing block devices. Signed-off-by: Nathan Scott <nathans@sgi.com> Signed-off-by: Jens Axboe <axboe@suse.de>
-rw-r--r--block/blktrace.c5
-rw-r--r--include/linux/blktrace_api.h1
2 files changed, 5 insertions, 1 deletions
diff --git a/block/blktrace.c b/block/blktrace.c
index 92925e7d9e6..b8c0702777f 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -69,7 +69,7 @@ static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK
/*
* Bio action bits of interest
*/
-static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC) };
+static u32 bio_act[5] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD) };
/*
* More could be added as needed, taking care to increment the decrementer
@@ -79,6 +79,8 @@ static u32 bio_act[3] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_AC
(((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0))
#define trace_sync_bit(rw) \
(((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
+#define trace_ahead_bit(rw) \
+ (((rw) & (1 << BIO_RW_AHEAD)) << (BIO_RW_AHEAD - 0))
/*
* The worker for the various blk_add_trace*() types. Fills out a
@@ -100,6 +102,7 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
what |= ddir_act[rw & WRITE];
what |= bio_act[trace_barrier_bit(rw)];
what |= bio_act[trace_sync_bit(rw)];
+ what |= bio_act[trace_ahead_bit(rw)];
pid = tsk->pid;
if (unlikely(act_log_check(bt, what, sector, pid)))
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index d95615fc6da..2346a1db856 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -19,6 +19,7 @@ enum blktrace_cat {
BLK_TC_FS = 1 << 8, /* fs requests */
BLK_TC_PC = 1 << 9, /* pc requests */
BLK_TC_NOTIFY = 1 << 10, /* special message */
+ BLK_TC_AHEAD = 1 << 11, /* readahead */
BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
};