On Fri, Apr 26, 2024 at 11:49:05AM -0700, Andrew Morton wrote:
> On Fri, 26 Apr 2024 19:29:38 +0800 Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
> > io_schedule+0x24/0xa0
> > __folio_lock+0x130/0x300
> > migrate_pages_batch+0x378/0x918
> > migrate_pages+0x350/0x700
> > compact_zone+0x63c/0xb38
> > compact_zone_order+0xc0/0x118
> > try_to_compact_pages+0xb0/0x280
> > __alloc_pages_direct_compact+0x98/0x248
> > __alloc_pages+0x510/0x1110
> > alloc_pages+0x9c/0x130
> > folio_alloc+0x20/0x78
> > filemap_alloc_folio+0x8c/0x1b0
> > page_cache_ra_order+0x174/0x308
> > ondemand_readahead+0x1c8/0x2b8
>
> I'm thinking
>
> Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
> Cc: stable
I think it goes back earlier than that.
https://lore.kernel.org/linux-mm/20200128060304.GA6615@xxxxxxxxxxxxxxxxxxxxxx/
details how it can happen with the old readpages code. It's just easier
to hit now.
