From: Shakeel Butt <shakeel.butt@linux.dev>
To: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>,
Uladzislau Rezki <urezki@gmail.com>,
Mikulas Patocka <mpatocka@redhat.com>,
"Vishal Moola (Oracle)" <vishal.moola@gmail.com>,
SeongJae Park <sj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
zkabelac@redhat.com, Matthew Sakai <msakai@redhat.com>,
linux-mm@kvack.org, dm-devel@lists.linux.dev
Subject: Re: [PATCH] mm: allow __GFP_RETRY_MAYFAIL in vmalloc
Date: Tue, 24 Feb 2026 06:22:15 -0800 [thread overview]
Message-ID: <aZ2zPzyoFUUNWdJ7@linux.dev> (raw)
In-Reply-To: <aZ2voRA5VJytcfLp@infradead.org>
On Tue, Feb 24, 2026 at 06:03:13AM -0800, Christoph Hellwig wrote:
> On Tue, Feb 24, 2026 at 01:22:36PM +0100, Michal Hocko wrote:
> > One thing that we could do to improve __GFP_RETRY_MAYFAIL resp.
> > __GFP_NORETRY is to use NOWAIT allocation semantic for page table
> > allocations as those could be achieved by scoped allocation context.
> > This could cause pre-mature failure after the whole bunch of memory has
> > already been allocated for the backing pages but considering that page
> > table allocations should be more and more rare over system runtime it
> > might be just a reasonable workaround. WDYT?
>
> Why bother? __GFP_RETRY_MAYFAIL has pretty lose semantics. Trying
> too hard to allocate PTEs is not breaking the overall concept.
>
One thing __GFP_RETRY_MAYFAIL is very clear about is to not trigger the
oom-killer which is not the case for GFP_KERNEL. There are users who explicitly
use __GFP_RETRY_MAYFAIL to avoid oom-killer.
Mikulas, is that the reason you are using __GFP_RETRY_MAYFAIL in your use-case?
next prev parent reply other threads:[~2026-02-24 14:22 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-12 16:33 Mikulas Patocka
2026-02-21 1:19 ` SeongJae Park
2026-02-23 5:48 ` Anshuman Khandual
2026-02-23 19:02 ` Vishal Moola (Oracle)
2026-02-23 19:25 ` Mikulas Patocka
2026-02-23 20:07 ` Uladzislau Rezki
2026-02-23 22:08 ` Michal Hocko
2026-02-24 11:39 ` Uladzislau Rezki
2026-02-24 12:22 ` Michal Hocko
2026-02-24 14:03 ` Christoph Hellwig
2026-02-24 14:22 ` Shakeel Butt [this message]
2026-02-24 14:26 ` Christoph Hellwig
2026-02-24 14:34 ` Michal Hocko
2026-02-24 15:38 ` Uladzislau Rezki
2026-02-24 15:44 ` Michal Hocko
2026-02-24 15:51 ` Michal Hocko
2026-02-24 16:07 ` Uladzislau Rezki
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