Commit 40359ccb authored by Nathan Scott's avatar Nathan Scott Committed by Jens Axboe

[PATCH] blktrace: readahead support

Provide the needed kernel support for distinguishing readahead
from regular read requests when tracing block devices.
Signed-off-by: default avatarNathan Scott <nathans@sgi.com>
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent fc0a75ce
......@@ -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)))
......
......@@ -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 */
};
......
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