From: Oleg Nesterov <oleg@redhat.com>
To: Andrea Calabrese <andrea.calabrese@amarulasolutions.com>
Cc: brauner@kernel.org, akpm@linux-foundation.org,
peterz@infradead.org, tglx@kernel.org, kexinsun@smail.nju.edu.cn,
adrianhuang0701@gmail.com, elver@google.com,
linux-kernel@vger.kernel.org, linux-amarula@amarulasolutions.com
Subject: Re: [PATCH] kernel: refactor: shorten has_pending_signals
Date: Tue, 19 May 2026 17:05:48 +0200 [thread overview]
Message-ID: <agx8TP9TXXnPBiBF@redhat.com> (raw)
In-Reply-To: <20260519103316.122139-3-andrea.calabrese@amarulasolutions.com>
Hi Andrea,
thanks, but perhaps you can cleanup the changelog?
On 05/19, Andrea Calabrese wrote:
>
> In has_pending_signals there was a switch/case pattern that did not need
> to be there, as the default for loop also covers those cases.
Yes, but this code is very, very old. I agree, this optimization makes no
sense with the modern compilers, but your description doesn't look accurate.
The switch/case code was added on purpose, even if the default loop covers
those cases.
> This patch does not change the binary output of the file
> kernel/signal.o.
I guess you tested x86. Good.
> A diff between the files gives shows (old -> new):
> 2072c2072
> < case 1: ready = signal->sig[0] &~ blocked->sig[0];
> ---
> > ready |= signal->sig[i] & ~blocked->sig[i];
> 2149c2149
> < case 1: ready = signal->sig[0] &~ blocked->sig[0];
> ---
> > ready |= signal->sig[i] & ~blocked->sig[i];
> 2155c2155
> < case 1: ready = signal->sig[0] &~ blocked->sig[0];
> ---
> > ready |= signal->sig[i] & ~blocked->sig[i];
> 9799c9799
> < case 1: ready = signal->sig[0] &~ blocked->sig[0];
> ---
> > ready |= signal->sig[i] & ~blocked->sig[i];
> 9805c9805
> < case 1: ready = signal->sig[0] &~ blocked->sig[0];
> ---
> > ready |= signal->sig[i] & ~blocked->sig[i];
I don't understand this part of your changelog, but I think it should
be removed anyway ;)
Oleg.
prev parent reply other threads:[~2026-05-19 15:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 10:33 [PATCH] kernel: refactor: shorten has_pending_signals Andrea Calabrese
2026-05-19 15:05 ` Oleg Nesterov [this message]
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