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author | Matthew Ahrens <[email protected]> | 2019-06-12 13:13:09 -0700 |
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committer | Brian Behlendorf <[email protected]> | 2019-06-12 13:13:09 -0700 |
commit | d9b4bf0665a0b1a7af2bbb34c60bca612956022d (patch) | |
tree | c90c5694edb1dd655ecbe46caac64c2be50229d7 /scripts | |
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 'scripts')
0 files changed, 0 insertions, 0 deletions