3836 zio_free() can be processed immediately in the common case
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/3836
  illumos/illumos-gate@9cb154a3c9

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
This commit is contained in:
Matthew Ahrens 2013-07-03 08:13:38 -08:00 committed by Brian Behlendorf
parent 498877baf5
commit 2883cad5b7
2 changed files with 28 additions and 6 deletions

View File

@ -24,7 +24,7 @@
*/
/*
* Copyright (c) 2012 by Delphix. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
*/
#ifndef _ZIO_IMPL_H
@ -38,7 +38,7 @@ extern "C" {
#endif
/*
* XXX -- Describe ZFS I/O pipleine here. Fill in as needed.
* XXX -- Describe ZFS I/O pipeline here. Fill in as needed.
*
* The ZFS I/O pipeline is comprised of various stages which are defined
* in the zio_stage enum below. The individual stages are used to construct
@ -213,7 +213,6 @@ enum zio_stage {
#define ZIO_FREE_PIPELINE \
(ZIO_INTERLOCK_STAGES | \
ZIO_STAGE_FREE_BP_INIT | \
ZIO_STAGE_ISSUE_ASYNC | \
ZIO_STAGE_DVA_FREE)
#define ZIO_DDT_FREE_PIPELINE \

View File

@ -783,7 +783,20 @@ void
zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
{
metaslab_check_free(spa, bp);
bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
/*
* Frees that are for the currently-syncing txg, are not going to be
* deferred, and which will not need to do a read (i.e. not GANG or
* DEDUP), can be processed immediately. Otherwise, put them on the
* in-memory list for later processing.
*/
if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) ||
txg != spa->spa_syncing_txg ||
spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) {
bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
} else {
VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0)));
}
}
zio_t *
@ -791,6 +804,7 @@ zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
enum zio_flag flags)
{
zio_t *zio;
enum zio_stage stage = ZIO_FREE_PIPELINE;
dprintf_bp(bp, "freeing in txg %llu, pass %u",
(longlong_t)txg, spa->spa_sync_pass);
@ -802,9 +816,18 @@ zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
metaslab_check_free(spa, bp);
arc_freed(spa, bp);
/*
* GANG and DEDUP blocks can induce a read (for the gang block header,
* or the DDT), so issue them asynchronously so that this thread is
* not tied up.
*/
if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp))
stage |= ZIO_STAGE_ISSUE_ASYNC;
zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags,
NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE);
NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags,
NULL, 0, NULL, ZIO_STAGE_OPEN, stage);
return (zio);
}