From: David Howells <dhowells@redhat.com>
To: Eric Biggers <ebiggers3@gmail.com>
Cc: dhowells@redhat.com, linux-crypto@vger.kernel.org,
Herbert Xu <herbert@gondor.apana.org.au>,
Tudor-Dan Ambarus <tudor.ambarus@microchip.com>,
Mat Martineau <mathew.j.martineau@linux.intel.com>,
Salvatore Benedetto <salvatore.benedetto@intel.com>,
keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
Eric Biggers <ebiggers@google.com>,
stable@vger.kernel.org
Subject: Re: [PATCH v2] lib/mpi: call cond_resched() from mpi_powm() loop
Date: Wed, 08 Nov 2017 12:50:17 +0000 [thread overview]
Message-ID: <25888.1510145417@warthog.procyon.org.uk> (raw)
In-Reply-To: <20171107221527.98433-1-ebiggers3@gmail.com>
Eric Biggers <ebiggers3@gmail.com> wrote:
> On a non-preemptible kernel, if KEYCTL_DH_COMPUTE is called with the
> largest permitted inputs (16384 bits), the kernel spends 10+ seconds
> doing modular exponentiation in mpi_powm() without rescheduling. If all
> threads do it, it locks up the system. Moreover, it can cause
> rcu_sched-stall warnings.
Do you want this to go in immediately, or I should I push it to James for the
next merge window?
David
next prev parent reply other threads:[~2017-11-08 12:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-07 22:15 [PATCH v2] lib/mpi: call cond_resched() from mpi_powm() loop Eric Biggers
2017-11-08 12:50 ` David Howells [this message]
2017-11-08 19:18 ` Eric Biggers
2017-11-08 20:17 ` David Howells
2017-11-08 20:28 ` Eric Biggers
2017-11-08 20:49 ` Mat Martineau
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