On Mon, Jun 13, 2022 at 8:08 PM Marek Szyprowski
<m.szyprowski@xxxxxxxxxxx> wrote:
>
> Hi Phillip,
>
> On 07.06.2022 09:35, Phillip Lougher wrote:
> > On 03/06/2022 13:54, Marek Szyprowski wrote:
> >> Hi,
> >>
> >> On 01.06.2022 12:39, Hsin-Yi Wang wrote:
> >>> Implement readahead callback for squashfs. It will read datablocks
> >>> which cover pages in readahead request. For a few cases it will
> >>> not mark page as uptodate, including:
> >>> - file end is 0.
> >>> - zero filled blocks.
> >>> - current batch of pages isn't in the same datablock or not enough in a
> >>> datablock.
> >>> - decompressor error.
> >>> Otherwise pages will be marked as uptodate. The unhandled pages will be
> >>> updated by readpage later.
> >>>
> >>> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> >>> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> >>> Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> >>> Reported-by: Phillip Lougher <phillip@xxxxxxxxxxxxxxx>
> >>> Reported-by: Xiongwei Song <Xiongwei.Song@xxxxxxxxxxxxx>
> >>> ---
> >>
> >> This patch landed recently in linux-next as commit 95f7a26191de
> >> ("squashfs: implement readahead"). I've noticed that it causes serious
> >> issues on my test systems (various ARM 32bit and 64bit based boards).
> >> The easiest way to observe is udev timeout 'waiting for /dev to be fully
> >> populated' and prolonged booting time. I'm using squashfs for deploying
> >> kernel modules via initrd. Reverting aeefca9dfae7 & 95f7a26191deon on
> >> top of the next-20220603 fixes the issue.
> >>
> >> Let me know how I can help debugging this issue. There is no hurry
> >> though, because the next week I will be on holidays.
> >
> > Hi Marek,
> >
> > Can you supply an example Squashfs filesystem and script that
> > reproduces the slow-down? Failing that, can you supply a copy
> > of your initrd/root-filesystem that can be run under emulation
> > to reproduce the issue? (I don't have any modern ARM embedded
> > systems).
> >
> > Again failing that, are you happy to test some debug code?
> >
> > Thanks
> >
> > Phillip (Squashfs maintainer and author).
>
> I've just got back from my holidays.
>
> Is this still relevant? I've noticed that v6 has been posted, but I
> failed to apply it on top of next-20220610 as mentioned in the
> cover-letter to test. I've also tried also to apply the mentioned
> 'Squashfs: handle missing pages decompressing into page cache' patchset.
> On the other hand, next-20220610 seems to be working fine on my setup now.
>
hi Marek,
next-20220610 contains v5 of the series. To apply v6, you need to
revert ca1505bf4805 ("squashfs: implement readahead") and 9d58b94aa73a
("squashfs: always build "file direct" version of page actor") first,
then apply 'Squashfs: handle missing pages decompressing into page
cache' patchset, then finally apply v6, since v6 is dependent on the
patchset.
Thanks.
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>
