Messages in this thread | | | From | Eric Dumazet <> | Date | Wed, 9 Mar 2022 09:32:29 -0800 | Subject | Re: [PATCH v2] mm/page_alloc: call check_new_pages() while zone spinlock is not held |
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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>
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