Re: [PATCH v9 2/8] mm/huge_memory: add two new (not yet used) functions for folio_split()

Hugh Dickins
2025-03-05T21:03:59Z

On Tue, 4 Mar 2025, Zi Yan wrote:
> On 4 Mar 2025, at 6:49, Hugh Dickins wrote:
> >
> > I'd been unable to complete even a single iteration of my "kernel builds
> > on huge tmpfs while swapping to SSD" testing during this current 6.14-rc
> > mm.git cycle (6.14-rc itself fine) - until the last week, when some
> > important fixes have come in, so I'm no longer getting I/O errors from
> > ext4-on-loop0-on-huge-tmpfs, and "Huh VM_FAULT_OOM leaked" warnings: good.
>
> This error should be related to the other patch I sent out on using
> xas_try_split() in shmem_large_entry_split(). Great to have you confirm
> it fixed some of the bugs.
>
> >
> > But I still can't get beyond a few iterations, a few minutes: there's
> > some corruption of user data, which usually manifests as a kernel build
> > failing because fixdep couldn't find some truncated-on-the-left pathname.
>
> It is likely that this patch might fix it (partially):
> https://lore.kernel.org/linux-mm/56EBE3B6-99EA-470E-B2B3-92C9C13032DF@nvidia.com/.
> Andrew has picked it yesterday.

No, that's a fix to a truncation issue which I had not hit:
I did try adding that patch, but it has not helped in my case.

Beyond checking that, I didn't have time yesterday to investigate
further, but I'll try again today (still using last weekend's mm.git).

Hugh