From: Hannes Frederic Sowa <hannes@redhat.com>
To: Marcelo Ricardo Leitner <mleitner@redhat.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH stable 3.4 2/2] ipv4: avoid parallel route cache gc executions
Date: Tue, 12 Aug 2014 20:50:37 +0200 [thread overview]
Message-ID: <1407869437.27163.6.camel@localhost> (raw)
In-Reply-To: <ffd56913c060fc717a74b87ba1a154125c9db2c4.1407796232.git.mleitner@redhat.com>
On Mo, 2014-08-11 at 19:41 -0300, Marcelo Ricardo Leitner wrote:
> When rt_intern_hash() has to deal with neighbour cache overflowing,
> it triggers the route cache garbage collector in an attempt to free
> some references on neighbour entries.
>
> Such call cannot be done async but should also not run in parallel with
> an already-running one, so that they don't collapse fighting over the
> hash lock entries.
>
> This patch thus blocks parallel executions by ignoring the call if
> garbage collector is already running on another CPU.
>
> We don't use a spinlock for it because now it runs on a work queue and
> we want it to be schedulable in-between the hash indexes.
>
> Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
> Cc: Hannes Frederic Sowa <hannes@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
next prev parent reply other threads:[~2014-08-12 18:50 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-11 22:41 [PATCH stable 3.4 1/2] ipv4: move route garbage collector to work queue Marcelo Ricardo Leitner
2014-08-11 22:41 ` [PATCH stable 3.4 2/2] ipv4: avoid parallel route cache gc executions Marcelo Ricardo Leitner
2014-08-12 18:50 ` Hannes Frederic Sowa [this message]
2014-08-12 18:50 ` [PATCH stable 3.4 1/2] ipv4: move route garbage collector to work queue Hannes Frederic Sowa
2014-08-12 20:23 ` Eric Dumazet
2014-08-12 21:41 ` Hannes Frederic Sowa
2014-08-12 22:42 ` David Miller
2014-08-12 23:11 ` Hannes Frederic Sowa
2014-08-13 0:46 ` David Miller
2014-08-13 1:50 ` Hannes Frederic Sowa
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