From: Johannes Weiner <hannes@cmpxchg.org>
To: Vlastimil Babka <vbabka@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
Brendan Jackman <jackmanb@google.com>, Zi Yan <ziy@nvidia.com>,
Mel Gorman <mgorman@techsingularity.net>,
Matthew Wilcox <willy@infradead.org>,
"David Hildenbrand (Arm)" <david@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Clark Williams <clrkwllms@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev
Subject: Re: [PATCH 2/3] mm/page_alloc: remove IRQ saving/restoring from pcp locking
Date: Mon, 2 Mar 2026 12:17:56 -0500 [thread overview]
Message-ID: <aaXGRMaW-tZGf-Wa@cmpxchg.org> (raw)
In-Reply-To: <20260227-b4-pcp-locking-cleanup-v1-2-f7e22e603447@kernel.org>
On Fri, Feb 27, 2026 at 06:07:59PM +0100, Vlastimil Babka wrote:
> Effectively revert commit 038a102535eb ("mm/page_alloc: prevent pcp
> corruption with SMP=n"). The original problem is now avoided by
> pcp_spin_trylock() always failing on CONFIG_SMP=n, so we do not need to
> disable IRQs anymore.
>
> It's not a complete revert, because keeping the pcp_spin_(un)lock()
> wrappers is useful. Rename them from _maybe_irqsave/restore to _nopin.
> The difference from pcp_spin_trylock()/pcp_spin_unlock() is that the
> _nopin variants don't perform pcpu_task_pin/unpin().
>
> Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
next prev parent reply other threads:[~2026-03-02 17:18 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-27 17:07 [PATCH 0/3] mm/page_alloc: pcp locking cleanup Vlastimil Babka
2026-02-27 17:07 ` [PATCH 1/3] mm/page_alloc: effectively disable pcp with CONFIG_SMP=n Vlastimil Babka
2026-03-02 17:12 ` Johannes Weiner
2026-02-27 17:07 ` [PATCH 2/3] mm/page_alloc: remove IRQ saving/restoring from pcp locking Vlastimil Babka
2026-03-02 17:17 ` Johannes Weiner [this message]
2026-02-27 17:08 ` [PATCH 3/3] mm/page_alloc: remove pcpu_spin_* wrappers Vlastimil Babka
2026-03-02 17:18 ` Johannes Weiner
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