From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: linux-kernel@vger.kernel.org, Sultan Alsawaf <sultan@kerneltoast.com>
Subject: Re: [PATCH] random: avoid reading two cache lines on irq randomness
Date: Wed, 28 Sep 2022 13:37:52 +0200 [thread overview]
Message-ID: <YzQyEFMNCcDmJMdX@linutronix.de> (raw)
In-Reply-To: <20220923182849.4145148-1-Jason@zx2c4.com>
On 2022-09-23 20:28:49 [+0200], Jason A. Donenfeld wrote:
> In order to avoid reading and dirtying two cache lines on every IRQ, move
> the work_struct to the bottom of the fast_pool struct. add_interrupt_
> randomness() always touches .pool and .count, which are currently split,
> because .mix pushes everything down. Instead, move .mix to the bottom,
> so that .pool and .count are always in the first cache line, since the
> .mix is only accessed when the pool is full.
>
> Fixes: 58340f8e952b ("random: defer fast pool mixing to worker")
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Cc: Sultan Alsawaf <sultan@kerneltoast.com>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Yup, makes sense.
Sebastian
prev parent reply other threads:[~2022-09-28 11:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-23 18:28 Jason A. Donenfeld
2022-09-28 11:37 ` Sebastian Andrzej Siewior [this message]
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