diff options
| author | Matthew Ahrens <[email protected]> | 2019-06-12 13:13:09 -0700 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2019-06-12 13:13:09 -0700 |
| commit | d9b4bf0665a0b1a7af2bbb34c60bca612956022d (patch) | |
| tree | c90c5694edb1dd655ecbe46caac64c2be50229d7 /module/zfs/zap_micro.c | |
| parent | d9cd66e45f285356624d26eb92e10e2baf2738ee (diff) | |
fat zap should prefetch when iterating
When iterating over a ZAP object, we're almost always certain to iterate
over the entire object. If there are multiple leaf blocks, we can
realize a performance win by issuing reads for all the leaf blocks in
parallel when the iteration begins.
For example, if we have 10,000 snapshots, "zfs destroy -nv
pool/fs@1%9999" can take 30 minutes when the cache is cold. This change
provides a >3x performance improvement, by issuing the reads for all ~64
blocks of each ZAP object in parallel.
Reviewed-by: Andreas Dilger <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Matthew Ahrens <[email protected]>
External-issue: DLPX-58347
Closes #8862
Diffstat (limited to 'module/zfs/zap_micro.c')
| -rw-r--r-- | module/zfs/zap_micro.c | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/module/zfs/zap_micro.c b/module/zfs/zap_micro.c index fa369f797..467812ff6 100644 --- a/module/zfs/zap_micro.c +++ b/module/zfs/zap_micro.c @@ -21,7 +21,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2011, 2017 by Delphix. All rights reserved. + * Copyright (c) 2011, 2018 by Delphix. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. * Copyright 2017 Nexenta Systems, Inc. */ @@ -1472,9 +1472,9 @@ zap_remove_uint64(objset_t *os, uint64_t zapobj, const uint64_t *key, * Routines for iterating over the attributes. */ -void -zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *os, uint64_t zapobj, - uint64_t serialized) +static void +zap_cursor_init_impl(zap_cursor_t *zc, objset_t *os, uint64_t zapobj, + uint64_t serialized, boolean_t prefetch) { zc->zc_objset = os; zc->zc_zap = NULL; @@ -1483,12 +1483,33 @@ zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *os, uint64_t zapobj, zc->zc_serialized = serialized; zc->zc_hash = 0; zc->zc_cd = 0; + zc->zc_prefetch = prefetch; +} +void +zap_cursor_init_serialized(zap_cursor_t *zc, objset_t *os, uint64_t zapobj, + uint64_t serialized) +{ + zap_cursor_init_impl(zc, os, zapobj, serialized, B_TRUE); } +/* + * Initialize a cursor at the beginning of the ZAP object. The entire + * ZAP object will be prefetched. + */ void zap_cursor_init(zap_cursor_t *zc, objset_t *os, uint64_t zapobj) { - zap_cursor_init_serialized(zc, os, zapobj, 0); + zap_cursor_init_impl(zc, os, zapobj, 0, B_TRUE); +} + +/* + * Initialize a cursor at the beginning, but request that we not prefetch + * the entire ZAP object. + */ +void +zap_cursor_init_noprefetch(zap_cursor_t *zc, objset_t *os, uint64_t zapobj) +{ + zap_cursor_init_impl(zc, os, zapobj, 0, B_FALSE); } void |