On Mon, Aug 12, 2024 at 7:37 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> On Mon, Aug 12, 2024 at 05:05:24PM +0800, Yafang Shao wrote:
> > The PF_MEMALLOC_NORECLAIM flag was introduced in commit eab0af905bfc
> > ("mm: introduce PF_MEMALLOC_NORECLAIM, PF_MEMALLOC_NOWARN"). To complement
> > this, let's add two helper functions, memalloc_nowait_{save,restore}, which
> > will be useful in scenarios where we want to avoid waiting for memory
> > reclamation.
>
> No, forcing nowait on callee contets is just asking for trouble.
> Unlike NOIO or NOFS this is incompatible with NOFAIL allocations
I don’t see any incompatibility in __alloc_pages_slowpath(). The
~__GFP_DIRECT_RECLAIM flag only ensures that direct reclaim is not
performed, but it doesn’t prevent the allocation of pages from
ALLOC_MIN_RESERVE, correct?
> and thus will lead to kernel crashes.
Could you please explain in detail where this might lead to kernel crashes?
--
Regards
Yafang
