Re: [PATCH 00/15] ubifs folio conversion

Richard Weinberger
2024-01-23T07:34:26Z

Matthew,

----- Ursprüngliche Mail -----
> Von: "Matthew Wilcox" <willy@infradead.org>
> An: "richard" <richard@nod.at>
> CC: "Matthew Wilcox" <willy@infradead.org>, "linux-mtd" <linux-mtd@lists.infradead.org>
> Gesendet: Sonntag, 21. Januar 2024 00:08:08
> Betreff: [PATCH 00/15] ubifs folio conversion

> This patchset converts ubifs to use folios throughout. I made some
> attempt to support large folios, but more work definitely needs to be
> done before it can be enabled. It's not clear to me whether it's worth
> doing, so I've left that for you ;-)

what is the benefit of large folios?

> The first patch fixes a misplaced call to SetPageUptodate which has been
> with us since the initial merge of ubifs. It looks to be a pretty hard
> race to hit, which is why it probably hasn't affected anyone.

Thanks a lot for identifying and fixing this one!

> With my usual test config, this saves about 2kB of kernel text (almost
> 1%). Some functions shrink more than others, eg ubifs_write_begin
> reduces by almost a third. YMMV with different configs.
>
> I've done a few other updates while I'm in here; eg setting/clearing
> PageError is pointless because the VFS doesn't use it and ubifs doesn't
> test it. And we're phasing out use of PagePrivate / folio_test_private()
> in favour of just testing whether folio->private is set.
>
> I ran this through xfstests and it didn't seem any worse.

Can you recommend a specific real load workload to stress test your changes?

Thanks,
//richard