[LU-17463] enable/disable page cache shrinker for mlocked pages on OSC layer

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: Qian Yingjin
• Reporter: Qian Yingjin

Description

Those pages mapped into VM_LOCKED [mlock()ed] VMAs should be unevictable pages:
i.e. mlocked pages via mlock() or mlockall() (see the URL for details: https://www.kernel.org/doc/html/v4.19/vm/unevictable-lru.html).

However, OSC page cache shrinker treats all cached page equally even some of them are unelectable. It may evict the mlocked pages wrongly.

We should disable page cache shrinker to avoid it evicting mlocked pages.

Issue Links

• is related to: LU-18397 mmap reads may not correctly update LDLM extent lock usage
• is related to: LU-18226 sanity: test_600b Error: 'unevict_mb is 99, expected 100'

Comments

[Gerrit Updater]

"Oleg Drokin <[e-mail]>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/53795/
Subject: LU-17463 osc: add option to disable page cache shrinker
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: d90ce0aab10ee8856140720cd71935da6877a5ab

[Gerrit Updater]

"Qian Yingjin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/54292
Subject: LU-17463 llite: put pages into unevict list inside mlock range
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: a2a872ac9b779380e9afcfa7e45e4cda55aa7ec4

[Gerrit Updater]

"Qian Yingjin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/54288
Subject: LU-17463 osc: put read page into unevictable list earlierly
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: ed72916cdbe33c6ff99a3a160faafb9d6b2ffc1c

[Gerrit Updater]

"Qian Yingjin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/54218
Subject: LU-17463 osc: scan the unevictable pages periodically
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 8d6495ccbb79406029e36b930b785c47c9984253

[Gerrit Updater]

"Qian Yingjin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/53826
Subject: LU-17463 osc: add support for unevitable mlock()ed pages
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 6c0213821095431a16ae36cddbaba7a02385cb3e

[Gerrit Updater]

"Qian Yingjin <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/53795
Subject: LU-17463 osc: add option to disable page cache shrinker
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: c243a844e6d66fdb7aac86618c38e3e9457b8e68