[LU-17916] Enable folio allocation support on the buffed io read/write path (BIO)

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Fix Version/s: Lustre 2.17.0
• Severity: 3
• Assignee: Shaun Tancheff
• Reporter: Shaun Tancheff

Description

When support for folios are added to generic_perform_write() we can enable folio based allocations without re-writing the lustre i/o path to use iomap:

https://www.spinics.net/lists/linux-nfs/msg104002.html
Updated patch:
https://lore.kernel.org/linux-fsdevel/[e-mail]/
Depends on (landed for v6.9):
https://patchwork.kernel.org/project/linux-fsdevel/patch/[e-mail]/

This is tested for NFS
https://www.spinics.net/lists/linux-nfs/msg104003.html

suggesting this alone is enough for a 2x improvement in buffered i/o.

Update lustre to use the folio allocation ie: __filemap_get_folio() instead of the grab_cache_page* family.

Provide a __filemap_get_folio() implementation for compatibility with older kernels.

Assuming no large regressions this should be available in kernel v6.11:
Linux kernel commit: v6.10-rc7-2-g9aac777aaf945
filemap: Convert generic_perform_write() to support large folios

Issue Links

• is related to: LU-15058 replace critical vmalloc allocations with kernel APIs to improve performance

Comments

[Gerrit Updater]

"Shaun Tancheff <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/58247
Subject: LU-17916 osc: switch to struct folio
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 5ff7d51d97ce0b9d602e52a8170865c15d7d5ddd

[Gerrit Updater]

"Shaun Tancheff <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/58097
Subject: LU-17916 llite: switch to struct folio
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 8d2836b0e47dff508e2616c33174015d22ed7349

[Gerrit Updater]

"Shaun Tancheff <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/57124
Subject: LU-17916 osd-ldiskfs: folio write support
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 6e801a92fe25e729b097cdc3a42bc713a814530e

[Gerrit Updater]

"Shaun Tancheff <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/55982
Subject: LU-17916 llite: large folio allocation option
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: e37acb2cadf176754fd03cda21953bccc222a24f

[Shaun Tancheff]

Tested with patched 6.6.13 kernel: https://github.com/stancheff/linux/tree/v6.6.13-3

[Shaun Tancheff]

Attached 0001-filemap-add-helper-mapping_max_folio_size.patch and 0002-filemap-Convert-generic_perform_write-to-support-lar.patch which can be applied to a 6.6 and later kernel to (safely) enable large folio support.

NOTE: Kernels v6.9 and later already have 0001-filemap-add-helper-mapping_max_folio_size.patch

[Gerrit Updater]

"Shaun Tancheff <[e-mail]>" uploaded a new patch: https://review.whamcloud.com/c/fs/lustre-release/+/55373
Subject: LU-17916 llite: prefer __filemap_get_folio
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 1da8bf55445d3a97b5cd50eca67a1e731115729a

[Gerrit Updater]

Abandoned patch