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From: Stephan Mueller <smueller@chronox.de>
To: linux-crypto@vger.kernel.org, Haixin Xu <jerryxucs@gmail.com>
Cc: linux-kernel@vger.kernel.org, herbert@gondor.apana.org.au,
	davem@davemloft.net, yifanwucs@gmail.com, tomapufckgml@gmail.com,
	yuantan098@gmail.com, bird@lzu.edu.cn, jerryxucs@gmail.com
Subject: Re: [PATCH 1/1] crypto: jitterentropy - replace long-held spinlock with mutex
Date: Mon, 30 Mar 2026 09:36:36 +0200	[thread overview]
Message-ID: <8044552.18pcnM708K@tauon> (raw)
In-Reply-To: <9a8ef1cbcc68b752a495acf0a23e7095eb0a7796.1774854094.git.jerryxucs@gmail.com>

Am Montag, 30. März 2026, 09:23:46 Mitteleuropäische Sommerzeit schrieb Haixin 
Xu:

Hi Haixin,

> jent_kcapi_random() serializes the shared jitterentropy state, but it
> currently holds a spinlock across the jent_read_entropy() call. That
> path performs expensive jitter collection and SHA3 conditioning, so
> parallel readers can trigger stalls as contending waiters spin for
> the same lock.
> 
> To prevent non-preemptible lock hold, replace rng->jent_lock with a
> mutex so contended readers sleep instead of spinning on a shared lock
> held across expensive entropy generation.

Thank you very much for the report and the patch.

Reviewed-by: Stephan Mueller <smueller@chronox.de>

Ciao
Stephan



  reply	other threads:[~2026-03-30  7:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-30  7:23 [PATCH 0/1] crypto: jitterentropy - fix long-held spinlock contention Haixin Xu
2026-03-30  7:23 ` [PATCH 1/1] crypto: jitterentropy - replace long-held spinlock with mutex Haixin Xu
2026-03-30  7:36   ` Stephan Mueller [this message]
2026-03-30  8:51   ` Herbert Xu
2026-03-30 13:50     ` Haixin Xu
2026-04-12  8:50   ` Herbert Xu

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