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 /include/sys | |
| 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 'include/sys')
| -rw-r--r-- | include/sys/zap.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/sys/zap.h b/include/sys/zap.h index ab13652d8..b19b46438 100644 --- a/include/sys/zap.h +++ b/include/sys/zap.h @@ -21,7 +21,7 @@ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2013 by Delphix. All rights reserved. + * Copyright (c) 2012, 2018 by Delphix. All rights reserved. * Copyright 2017 Nexenta Systems, Inc. */ @@ -350,6 +350,7 @@ typedef struct zap_cursor { uint64_t zc_serialized; uint64_t zc_hash; uint32_t zc_cd; + boolean_t zc_prefetch; } zap_cursor_t; typedef struct { @@ -375,7 +376,9 @@ typedef struct { * Initialize a zap cursor, pointing to the "first" attribute of the * zapobj. You must _fini the cursor when you are done with it. */ -void zap_cursor_init(zap_cursor_t *zc, objset_t *ds, uint64_t zapobj); +void zap_cursor_init(zap_cursor_t *zc, objset_t *os, uint64_t zapobj); +void zap_cursor_init_noprefetch(zap_cursor_t *zc, objset_t *os, + uint64_t zapobj); void zap_cursor_fini(zap_cursor_t *zc); /* |