From: Linus Torvalds <torvalds@linux-foundation.org>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH] mm: remove unintentional voluntary preemption in get_mmap_lock_carefully
Date: Sun, 20 Aug 2023 14:47:41 +0200 [thread overview]
Message-ID: <CAHk-=wh=cECn7SLr31VXwtJq-wYnt5+VcERnvAmEVktdEKqR=w@mail.gmail.com> (raw)
In-Reply-To: <CAGudoHG3OxoYKSwDmJYEDOj6LmDMsQDs3SD5nBdrzA5Vc1_H0A@mail.gmail.com>
On Sun, 20 Aug 2023 at 14:41, Mateusz Guzik <mjguzik@gmail.com> wrote:
>
> On 8/20/23, Matthew Wilcox <willy@infradead.org> wrote:
> >
> > Except now we search the exception tables every time we call it.
> > The now-deleted comment (c2508ec5a58d) suggests this is slow:
Yeah, that was the intent.
But I agree that we should basically avoid trying to sleep just as we
got the lock.
> My first patch looked like this:
Well, that's disgusting and strange.
> - might_sleep();
> +#if defined(CONFIG_DEBUG_ATOMIC_SLEEP)
> + __might_sleep(__FILE__, __LINE__);
> +#endif
Why would you have that strange #ifdef? __might_sleep() just goes away
without that debug option anyway.
But without that odd ifdef, I think it's fine.
Linus
next prev parent reply other threads:[~2023-08-20 12:48 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-20 10:43 Mateusz Guzik
2023-08-20 11:36 ` Matthew Wilcox
2023-08-20 12:41 ` Mateusz Guzik
2023-08-20 12:46 ` Mateusz Guzik
2023-08-20 12:47 ` Linus Torvalds [this message]
2023-08-20 12:59 ` Linus Torvalds
2023-08-20 13:08 ` Mateusz Guzik
2023-08-20 13:00 ` Mateusz Guzik
2023-08-20 18:12 ` Matthew Wilcox
2023-08-21 1:13 ` Mateusz Guzik
2023-08-21 3:58 ` Matthew Wilcox
2023-08-21 4:55 ` Linus Torvalds
2023-08-21 5:38 ` Linus Torvalds
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