Re: [PATCH v14 000/138] Memory folios

[Mike Rapoport]

On Tue, Jul 20, 2021 at 04:23:29PM +0100, Matthew Wilcox wrote:
> On Tue, Jul 20, 2021 at 06:17:26PM +0300, Mike Rapoport wrote:
> > On Tue, Jul 20, 2021 at 01:41:15PM +0100, Matthew Wilcox wrote:
> > > On Tue, Jul 20, 2021 at 01:54:38PM +0300, Mike Rapoport wrote:
> > > > Most of the changelogs (at least at the first patches) mention reduction of
> > > > the kernel size for your configuration on x86. I wonder, what happens if
> > > > you build the kernel with "non-distro" configuration, e.g. defconfig or
> > > > tiny.config?
> > > 
> > > I did an allnoconfig build and that reduced in size by ~2KiB.
> > > 
> > > > Also, what is the difference on !x86 builds?
> > > 
> > > I don't generally do non-x86 builds ... feel free to compare for
> > > yourself!
> > 
> > I did allnoconfig and defconfig for arm64 and powerpc.
> > 
> > All execpt arm64::defconfig show decrease by ~1KiB, while arm64::defconfig
> > was actually increased by ~500 bytes.
> 
> Which patch did you go up to for that?  If you're going past patch 50 or
> so, then you're starting to add functionality (ie support for arbitrary
> order pages), so a certain amount of extra code size might be expected.
> I measured 6KB at patch 32 or so, then between patch 32 & 50 was pretty
> much a wash.

I've used folio_14 tag:

commit 480552d0322d855d146c0fa6fdf1e89ca8569037 (HEAD, tag: folio_14)
Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Date:   Wed Feb 5 11:27:01 2020 -0500

    mm/readahead: Add multi-page folio readahead
 
-- 
Sincerely yours,
Mike.