ZIO: Optimize zio_flush()

- Generalize vdev_nowritecache handling by traversing through the
VDEV tree and skipping children ZIOs where not supported.
 - Remove intermediate zio_null() in case of several VDEV children.
 - Remove children handling from zio_ioctl().  There are no other
use cases for this code beside DKIOCFLUSHWRITECACHED, and would there
be, I doubt they would so straightforward apply to all VDEV children.

Comparing to removed previous optimization this should improve cases
of redundant ZILs/SLOGs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #15515
This commit is contained in:
Alexander Motin 2023-11-17 17:00:59 -05:00 committed by Brian Behlendorf
parent 7ea8331009
commit 8b1a132de7
2 changed files with 16 additions and 22 deletions

View File

@ -1622,7 +1622,7 @@ zil_lwb_write_done(zio_t *zio)
while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
if (vd != NULL && !vd->vdev_nowritecache) {
if (vd != NULL) {
/*
* The "ZIO_FLAG_DONT_PROPAGATE" is currently
* always used within "zio_flush". This means,

View File

@ -1435,23 +1435,10 @@ zio_t *
zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
zio_done_func_t *done, void *private, zio_flag_t flags)
{
zio_t *zio;
int c;
if (vd->vdev_children == 0) {
zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
zio_t *zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
zio->io_cmd = cmd;
} else {
zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
for (c = 0; c < vd->vdev_children; c++)
zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
done, private, flags));
}
return (zio);
}
@ -1622,11 +1609,18 @@ zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
}
void
zio_flush(zio_t *zio, vdev_t *vd)
zio_flush(zio_t *pio, vdev_t *vd)
{
zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
NULL, NULL,
ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
if (vd->vdev_nowritecache)
return;
if (vd->vdev_children == 0) {
zio_nowait(zio_ioctl(pio, vd->vdev_spa, vd,
DKIOCFLUSHWRITECACHE, NULL, NULL, ZIO_FLAG_CANFAIL |
ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
} else {
for (uint64_t c = 0; c < vd->vdev_children; c++)
zio_flush(pio, vd->vdev_child[c]);
}
}
void