From: Andrew Morton <akpm@linux-foundation.org>
To: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@redhat.com>,
Oscar Salvador <osalvador@suse.de>,
Johannes Weiner <hannes@cmpxchg.org>,
Vlastimil Babka <vbabka@suse.cz>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/page_alloc: Add lockdep assertion for pageblock type change
Date: Thu, 27 Feb 2025 14:33:02 -0800 [thread overview]
Message-ID: <20250227143302.2338b1cf15919c64a6c1eb27@linux-foundation.org> (raw)
In-Reply-To: <20250227-pageblock-lockdep-v1-1-3701efb331bb@google.com>
On Thu, 27 Feb 2025 16:15:47 +0000 Brendan Jackman <jackmanb@google.com> wrote:
> Since the migratetype hygiene patches [0], the locking here is
> a bit more formalised, so write it down with an assert.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -417,6 +417,10 @@ void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
>
> void set_pageblock_migratetype(struct page *page, int migratetype)
> {
> + lockdep_assert_once(system_state == SYSTEM_BOOTING ||
> + in_mem_hotplug() ||
> + lockdep_is_held(&page_zone(page)->lock));
> +
> if (unlikely(page_group_by_mobility_disabled &&
> migratetype < MIGRATE_PCPTYPES))
> migratetype = MIGRATE_UNMOVABLE;
>
We could add such assertions all over the place. Why this place in
particular?
next prev parent reply other threads:[~2025-02-27 22:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-27 16:15 Brendan Jackman
2025-02-27 22:33 ` Andrew Morton [this message]
2025-02-28 9:20 ` Brendan Jackman
2025-02-28 10:12 ` Vlastimil Babka
2025-02-28 17:31 ` kernel test robot
2025-02-28 18:28 ` Johannes Weiner
2025-03-03 11:18 ` Andy Shevchenko
2025-03-03 23:13 ` Stephen Rothwell
2025-03-04 10:18 ` Brendan Jackman
2025-03-04 10:31 ` David Hildenbrand
2025-02-28 23:42 ` kernel test robot
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