Re: [GIT PULL] bcachefs

Kent Overstreet
2023-06-27T03:28:51Z

On Tue, Jun 27, 2023 at 04:19:33AM +0100, Matthew Wilcox wrote:
> On Mon, Jun 26, 2023 at 08:59:44PM -0600, Jens Axboe wrote:
> > On 6/26/23 8:33?PM, Kent Overstreet wrote:
> > > On Mon, Jun 26, 2023 at 07:13:54PM -0600, Jens Axboe wrote:
> > >> fs/bcachefs/alloc_background.c: In function ?bch2_check_alloc_info?:
> > >> fs/bcachefs/alloc_background.c:1526:1: warning: the frame size of 2640 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> > >> 1526 | }
> > >> | ^
> > >> fs/bcachefs/reflink.c: In function ?bch2_remap_range?:
> > >> fs/bcachefs/reflink.c:388:1: warning: the frame size of 2352 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> > >> 388 | }
> > >> | ^
> > >
> > > What version of gcc are you using? I'm not seeing either of those
> > > warnings - I'm wondering if gcc recently got better about stack usage
> > > when inlining.
> >
> > Using:
> >
> > gcc (Debian 13.1.0-6) 13.1.0
> >
> > and it's on arm64, fwiw.
>
> OOI what PAGE_SIZE do you have configured? Sometimes fs data structures
> are PAGE_SIZE dependent (haven't looked at this particular bcachefs data
> structure). We've also had weirdness with various gcc versions on some
> architectures making different inlining decisions from x86.

There are very few references to PAGE_SIZE in bcachefs, I've killed off
as much of that as I can because all this code has to work in userspace
too and depending on PAGE_SIZE is sketchy there