From: Eric Dumazet <edumazet@google.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>, Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeelb@google.com>, Wei Xu <weixugc@google.com>,
Greg Thelen <gthelen@google.com>, Hugh Dickins <hughd@google.com>,
David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v2] mm/page_alloc: call check_new_pages() while zone spinlock is not held
Date: Wed, 9 Mar 2022 09:32:29 -0800 [thread overview]
Message-ID: <CANn89iKy2_hutqReS9oa+e9d6Eao639=-PXA=9r5oNkqeh46rg@mail.gmail.com> (raw)
In-Reply-To: <20220309123245.GI15701@techsingularity.net>
On Wed, Mar 9, 2022 at 4:32 AM Mel Gorman <mgorman@techsingularity.net> wrote:
> We should because it was an oversight. Thanks for pointing that out.
>
> > Or was it a conscious choice of yours ?
> > (I presume part of the performance gains came from
> > not having to bring ~7 cache lines per 32KB chunk on x86)
> >
>
> There will be a performance penalty due to the check but it's a correctness
> vs performance issue.
>
> This? It's boot tested only.
>
> --8<--
> mm/page_alloc: check high-order pages for corruption during PCP operations
>
> Eric Dumazet pointed out that commit 44042b449872 ("mm/page_alloc: allow
> high-order pages to be stored on the per-cpu lists") only checks the head
> page during PCP refill and allocation operations. This was an oversight
> and all pages should be checked. This will incur a small performance
> penalty but it's necessary for correctness.
>
> Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists")
> Reported-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> ---
SGTM, thanks Mel !
Acked-by: Eric Dumazet <edumazet@google.com>
next prev parent reply other threads:[~2022-03-09 17:32 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-04 17:02 Eric Dumazet
2022-03-04 19:19 ` Shakeel Butt
2022-03-06 22:15 ` David Rientjes
2022-03-07 9:15 ` Mel Gorman
2022-03-08 23:49 ` Eric Dumazet
2022-03-09 12:32 ` Mel Gorman
2022-03-09 17:32 ` Eric Dumazet [this message]
2022-03-12 15:43 ` [mm/page_alloc] 8212a964ee: vm-scalability.throughput 30.5% improvement kernel test robot
2022-03-12 18:58 ` Vlastimil Babka
2022-03-12 23:26 ` Eric Dumazet
2022-03-13 9:28 ` Vlastimil Babka
2022-03-13 21:10 ` Eric Dumazet
2022-03-13 21:18 ` Matthew Wilcox
2022-03-13 21:27 ` Eric Dumazet
2022-03-13 21:36 ` Eric Dumazet
2022-03-14 9:09 ` Vlastimil Babka
2022-03-07 9:24 ` [PATCH v2] mm/page_alloc: call check_new_pages() while zone spinlock is not held Vlastimil Babka
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