[LU-14838] Remove old lockless code: Truncate & contention based lockless i/o

• Status: Resolved
• Project: Lustre
• Fix Version/s: Lustre 2.12.10
• Type: Bug
• Priority: Minor
• Reporter: Patrick Farrell
• Assignee: Patrick Farrell
• Resolution: Fixed
• Severity: 3

Description

Lockless truncate and the buffered lockless i/o on contention have been broken pretty much since they were first implemented, which was a long time ago (~Lustre 2.0, maybe earlier).

It's past time to remove them both.  The only reason the lockless i/o on contention hasn't been more of a problem is that contention detection on the server is also mostly broken.

 

One note:
I am going to leave the server side code in place for now, because I have a rewrite of it here:
https://review.whamcloud.com/#/c/35287/

And while I do not expect to pick up automatic lockahead, this contention detection work has a role to play in the "switched buffered i/o to direct i/o" patch series.

It is much easier to do that patch if the server side contention detection is not removed entirely.

Comments

[Gerrit Updater]

Patrick Farrell ([e-mail]) uploaded a new patch: https://review.whamcloud.com/44206
Subject: LU-14838 ldlm: Disable lockless on contention
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: cd05dc35611c3642732074b8ed15977a5d823cd1

[Gerrit Updater]

Patrick Farrell ([e-mail]) uploaded a new patch: https://review.whamcloud.com/44205
Subject: LU-14838 osc: Remove client contention support
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 936d85d6023a9d5a24f95aefd71d8a48b23d3cb9

[Gerrit Updater]

Patrick Farrell ([e-mail]) uploaded a new patch: https://review.whamcloud.com/44204
Subject: LU-14838 osc: Remove lockless truncate
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 44048d0152e075cf82239272a4f4106e8b58b9f8

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/44204/
Subject: LU-14838 osc: Remove lockless truncate
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 6335dba83995765c1ffcd7993eb8958c162913e1

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/44205/
Subject: LU-14838 osc: Remove client contention support
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 5ad00e36eca11a1469588bd7b7b4d8df1c32eb27

[Gerrit Updater]

"Andreas Dilger <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/47554
Subject: LU-14838 tests: skip sanityn/32a if no truncate_lock
Project: fs/lustre-release
Branch: b2_12
Current Patch Set: 1
Commit: c4a8646f2116dd7f389de13782849edf865eb31d

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/47554/
Subject: LU-14838 tests: skip sanityn/32a if no truncate_lock
Project: fs/lustre-release
Branch: b2_12
Current Patch Set:
Commit: 45b141f2ed601af8db57a8a1fcc810a92d9cd939

[Peter Jones]

Landed for 2.12.10