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- Reduce contention on the global bdonelock and bpinlock by using

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a pool mutex to protect these sleep/wakeup/counter races.  This
   still is preferable to bloating each bio with a mtx.
This commit is contained in:
jeff 2008-03-21 10:00:05 +00:00
parent ba540b27d6
commit 72142b2fae
1 changed files with 34 additions and 30 deletions
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64
sys/kern/vfs_bio.c
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@ -236,17 +236,6 @@ static int needsbuffer;
*/
static struct mtx nblock;
/*
* Lock that protects against bwait()/bdone()/B_DONE races.
*/
static struct mtx bdonelock;
/*
* Lock that protects against bwait()/bdone()/B_DONE races.
*/
static struct mtx bpinlock;
/*
* Definitions for the buffer free lists.
*/
@ -540,8 +529,6 @@ bufinit(void)
mtx_init(&rbreqlock, "runningbufspace lock", NULL, MTX_DEF);
mtx_init(&nblock, "needsbuffer lock", NULL, MTX_DEF);
mtx_init(&bdlock, "buffer daemon lock", NULL, MTX_DEF);
mtx_init(&bdonelock, "bdone lock", NULL, MTX_DEF);
mtx_init(&bpinlock, "bpin lock", NULL, MTX_DEF);
/* next, make a null set of free lists */
for (i = 0; i < BUFFER_QUEUES; i++)
@ -2994,14 +2981,16 @@ allocbuf(struct buf *bp, int size)
void
biodone(struct bio *bp)
{
struct mtx *mtxp;
void (*done)(struct bio *);
mtx_lock(&bdonelock);
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
bp->bio_flags |= BIO_DONE;
done = bp->bio_done;
if (done == NULL)
wakeup(bp);
mtx_unlock(&bdonelock);
mtx_unlock(mtxp);
if (done != NULL)
done(bp);
}
@ -3015,11 +3004,13 @@ biodone(struct bio *bp)
int
biowait(struct bio *bp, const char *wchan)
{
struct mtx *mtxp;
mtx_lock(&bdonelock);
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
while ((bp->bio_flags & BIO_DONE) == 0)
msleep(bp, &bdonelock, PRIBIO, wchan, hz / 10);
mtx_unlock(&bdonelock);
msleep(bp, mtxp, PRIBIO, wchan, hz / 10);
mtx_unlock(mtxp);
if (bp->bio_error != 0)
return (bp->bio_error);
if (!(bp->bio_flags & BIO_ERROR))
@ -3781,21 +3772,25 @@ vunmapbuf(struct buf *bp)
void
bdone(struct buf *bp)
{
struct mtx *mtxp;
mtx_lock(&bdonelock);
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
bp->b_flags |= B_DONE;
wakeup(bp);
mtx_unlock(&bdonelock);
mtx_unlock(mtxp);
}
void
bwait(struct buf *bp, u_char pri, const char *wchan)
{
struct mtx *mtxp;
mtx_lock(&bdonelock);
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
while ((bp->b_flags & B_DONE) == 0)
msleep(bp, &bdonelock, pri, wchan, 0);
mtx_unlock(&bdonelock);
msleep(bp, mtxp, pri, wchan, 0);
mtx_unlock(mtxp);
}
int
@ -3873,27 +3868,36 @@ bufobj_wwait(struct bufobj *bo, int slpflag, int timeo)
void
bpin(struct buf *bp)
{
mtx_lock(&bpinlock);
struct mtx *mtxp;
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
bp->b_pin_count++;
mtx_unlock(&bpinlock);
mtx_unlock(mtxp);
}
void
bunpin(struct buf *bp)
{
mtx_lock(&bpinlock);
struct mtx *mtxp;
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
if (--bp->b_pin_count == 0)
wakeup(bp);
mtx_unlock(&bpinlock);
mtx_unlock(mtxp);
}
void
bunpin_wait(struct buf *bp)
{
mtx_lock(&bpinlock);
struct mtx *mtxp;
mtxp = mtx_pool_find(mtxpool_sleep, bp);
mtx_lock(mtxp);
while (bp->b_pin_count > 0)
msleep(bp, &bpinlock, PRIBIO, "bwunpin", 0);
mtx_unlock(&bpinlock);
msleep(bp, mtxp, PRIBIO, "bwunpin", 0);
mtx_unlock(mtxp);
}
#include "opt_ddb.h"