From: Mel Gorman <mgorman@techsingularity.net>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Nicolas Saenz Julienne <nsaenzju@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Michal Hocko <mhocko@kernel.org>, Hugh Dickins <hughd@google.com>,
Yu Zhao <yuzhao@google.com>,
Marek Szyprowski <m.szyprowski@samsung.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH 5/7] mm/page_alloc: Protect PCP lists with a spinlock
Date: Tue, 5 Jul 2022 08:20:34 +0100 [thread overview]
Message-ID: <20220705072034.GC27531@techsingularity.net> (raw)
In-Reply-To: <5f464a89-91b4-f432-99a9-45968fc80631@suse.cz>
On Mon, Jul 04, 2022 at 02:31:17PM +0200, Vlastimil Babka wrote:
> On 6/24/22 14:54, Mel Gorman wrote:
> > Currently the PCP lists are protected by using local_lock_irqsave to
> > prevent migration and IRQ reentrancy but this is inconvenient. Remote
> > draining of the lists is impossible and a workqueue is required and every
> > task allocation/free must disable then enable interrupts which is
> > expensive.
> >
> > As preparation for dealing with both of those problems, protect the lists
> > with a spinlock. The IRQ-unsafe version of the lock is used because IRQs
> > are already disabled by local_lock_irqsave. spin_trylock is used in
> > preparation for a time when local_lock could be used instead of
> > lock_lock_irqsave.
>
> ^ local_lock_irqsave?
>
More appropriate given how the series evolved would be;
spin_trylock is used in combination with local_lock_irqsave() but later
will be replaced with a spin_trylock_irqsave when the local_lock is
removed.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2022-07-05 7:20 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-24 12:54 [PATCH v5 00/7] Drain remote per-cpu directly Mel Gorman
2022-06-24 12:54 ` [PATCH 1/7] mm/page_alloc: Add page->buddy_list and page->pcp_list Mel Gorman
2022-06-24 12:54 ` [PATCH 2/7] mm/page_alloc: Use only one PCP list for THP-sized allocations Mel Gorman
2022-06-24 12:54 ` [PATCH 3/7] mm/page_alloc: Split out buddy removal code from rmqueue into separate helper Mel Gorman
2022-06-24 12:54 ` [PATCH 4/7] mm/page_alloc: Remove mistaken page == NULL check in rmqueue Mel Gorman
2022-06-24 12:54 ` [PATCH 5/7] mm/page_alloc: Protect PCP lists with a spinlock Mel Gorman
2022-07-04 12:31 ` Vlastimil Babka
2022-07-05 7:20 ` Mel Gorman [this message]
2022-07-04 16:32 ` Nicolas Saenz Julienne
2022-06-24 12:54 ` [PATCH 6/7] mm/page_alloc: Remotely drain per-cpu lists Mel Gorman
2022-07-04 14:28 ` Vlastimil Babka
2022-06-24 12:54 ` [PATCH 7/7] mm/page_alloc: Replace local_lock with normal spinlock Mel Gorman
2022-06-24 18:59 ` Yu Zhao
2022-06-27 8:46 ` [PATCH] mm/page_alloc: Replace local_lock with normal spinlock -fix Mel Gorman
2022-07-04 14:39 ` [PATCH 7/7] mm/page_alloc: Replace local_lock with normal spinlock Vlastimil Babka
2022-07-04 16:33 ` Nicolas Saenz Julienne
2022-07-03 23:28 ` [PATCH v5 00/7] Drain remote per-cpu directly Andrew Morton
2022-07-03 23:31 ` Yu Zhao
2022-07-03 23:35 ` Andrew Morton
-- strict thread matches above, loose matches on Subject: below --
2022-06-13 12:56 [PATCH v4 " Mel Gorman
2022-06-13 12:56 ` [PATCH 5/7] mm/page_alloc: Protect PCP lists with a spinlock Mel Gorman
2022-06-16 15:59 ` Vlastimil Babka
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