Regression on linux-next (next-20240228)

[Borah, Chaitanya Kumar]

Hello Mathew,

> -----Original Message-----
> From: Matthew Wilcox <willy at infradead.org>
> Sent: Monday, March 4, 2024 11:27 AM
> To: Borah, Chaitanya Kumar <chaitanya.kumar.borah at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Kurmi, Suresh Kumar
> <suresh.kumar.kurmi at intel.com>; Saarinen, Jani <jani.saarinen at intel.com>
> Subject: Re: Regression on linux-next (next-20240228)
> 
> On Mon, Mar 04, 2024 at 04:49:47AM +0000, Borah, Chaitanya Kumar
> wrote:
> > After bisecting the tree, the following patch [4] seems to be the first "bad"
> > commit
> >
> > ``````````````````````````````````````````````````````````````````````
> > ```````````````````````````````````
> > commit ac7130117e8860081be88149061b5abb654d5759
> > Author: Matthew Wilcox (Oracle) mailto:willy at infradead.org
> > Date:   Tue Feb 27 17:42:41 2024 +0000
> >
> >     mm: use free_unref_folios() in put_pages_list()
> >
> >     Break up the list of folios into batches here so that the folios
> > are more
> >     likely to be cache hot when doing the rest of the processing.
> >
> >     Link:
> > https://lkml.kernel.org/r/20240227174254.710559-8-willy@infradead.org
> >     Signed-off-by: Matthew Wilcox (Oracle) mailto:willy at infradead.org
> > ``````````````````````````````````````````````````````````````````````
> > ```````````````````````````````````
> >
> > We could not revert the patch because of a build errors but resetting
> > to the parent of the commit seems to fix the issue
> >
> > Could you please check why the patch causes this regression and provide a
> fix if necessary?
> 
> Could you try putting the two:
> 
> -                       list_del(&folio->lru);
> 
> statements back in and see if that fixes it?

That seems to fix it.

                if (!folio_put_testzero(folio))
+                       list_del(&folio->lru);
                        continue;
                if (folio_test_large(folio)) {
                        __folio_put_large(folio);
+                       list_del(&folio->lru);
                        continue;
                }
Regards

Chaitanya