[LU-8047] optimize ll_md_blocking_ast() for a failed lock Created: 20/Apr/16  Updated: 21/Jun/19  Resolved: 21/Mar/19

Status: Resolved
Project: Lustre
Component/s: None
Affects Version/s: Lustre 2.9.0
Fix Version/s: Lustre 2.13.0, Lustre 2.12.3

Type: Bug Priority: Minor
Reporter: Andrew Perepechko Assignee: Andrew Perepechko
Resolution: Fixed Votes: 0
Labels: patch

Issue Links:
Related
Severity: 3
Rank (Obsolete): 9223372036854775807

 Description   

When investigating performance issues with LU-4398, we've found that if the MDS does not return a lock for an open request, ll_md_blocking_ast() will be called for a failed UPDATE lock on the corresponding directory. ll_invalidate_negative_children() will process the whole cache associated with the directory in order to find negative entries and invalidate them.

If a directory has millions of cached dentries, ll_invalidate_negative_children() spends several scheduler ticks just to process the list. There is clearly some room for ll_invalidate_negative_children() optimization, but we'd like to optimize at least ll_md_blocking_ast() to avoid processing for not granted locks.

A patch will be uploaded shortly.



 Comments   
Comment by Gerrit Updater [ 20/Apr/16 ]

Andrew Perepechko (andrew.perepechko@seagate.com) uploaded a new patch: http://review.whamcloud.com/19665
Subject: LU-8047 llite: optimizations for not granted lock processing
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 18b15ab0fe7cd2157aee1e3dcef019c77ef61a53

Comment by Aurelien Degremont (Inactive) [ 06/Dec/18 ]

The attached patch looked good but was not landed at the end. Any news on this front?

Comment by Gerrit Updater [ 21/Mar/19 ]

Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/19665/
Subject: LU-8047 llite: optimizations for not granted lock processing
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 2c126c5a73edea434456c6c335772daaac717f2f

Comment by Peter Jones [ 21/Mar/19 ]

Landed for 2.13

Comment by Gerrit Updater [ 30/May/19 ]

Minh Diep (mdiep@whamcloud.com) uploaded a new patch: https://review.whamcloud.com/35001
Subject: LU-8047 llite: optimizations for not granted lock processing
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: 52020b50d419b05028c874fb7681060a2ef06f0d

Comment by Gerrit Updater [ 20/Jun/19 ]

Oleg Drokin (green@whamcloud.com) merged in patch https://review.whamcloud.com/35001/
Subject: LU-8047 llite: optimizations for not granted lock processing
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: d543393c7b99ee8482e4cbda36dfe4f54aa15bb6

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