Re: [PATCH 0/6] shmem: high order folios support in write path

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On 15.09.23 11:51, Daniel Gomez wrote:
This series add support for high order folios in shmem write

This is a continuation of the shmem work from Luis here [1]
following Matthew Wilcox's suggestion [2] regarding the path to take
for the folio allocation order calculation.

[1] RFC v2 add support for blocksize > PAGE_SIZE

Patches have been tested and sent from next-230911. They do apply
cleanly to the latest next-230914.

fsx and fstests has been performed on tmpfs with noswap with the
following results:
- fsx: 2d test, 21,5B
- fstests: Same result as baseline for next-230911 [3][4][5]

[3] Baseline next-230911 failures are: generic/080 generic/126
generic/193 generic/633 generic/689
[4] fstests logs baseline:
[5] fstests logs patches:

There are at least 2 cases/topics to handle that I'd appreciate
1. With the new strategy, you might end up with a folio order matching
HPAGE_PMD_ORDER. However, we won't respect the 'huge' flag anymore if
THP is enabled.
2. When the above (1.) occurs, the code skips the huge path, so
xa_find with hindex is skipped.

Similar to large anon folios (but different to large non-shmem folios in the pagecache), this can result in memory waste.

We discussed that topic in the last bi-weekly mm meeting, and also how to eventually configure that for shmem.

Refer to of a summary. [1]



David / dhildenb

[Index of Archives]     [XFS Filesystem Development (older mail)]     [Linux Filesystem Development]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux RAID]     [Linux SCSI]

  Powered by Linux