Subject: Re: [PATCH stable 3.4 1/2] ipv4: move route garbage collector to work queue

From: Hannes Frederic Sowa <[email-masked]>
Date: Tue, 12 Aug 2014 20:50:04 +0200

On Mo, 2014-08-11 at 19:41 -0300, Marcelo Ricardo Leitner wrote:
> Currently the route garbage collector gets called by dst_alloc() if it
> have more entries than the threshold. But it's an expensive call, that
> don't really need to be done by then.
> 
> Another issue with current way is that it allows running the garbage
> collector with the same start parameters on multiple CPUs at once, which
> is not optimal. A system may even soft lockup if the cache is big enough
> as the garbage collectors will be fighting over the hash lock entries.
> 
> This patch thus moves the garbage collector to run asynchronously on a
> work queue, much similar to how rt_expire_check runs.
> 
> There is one condition left that allows multiple executions, which is
> handled by the next patch.
> 
> Signed-off-by: Marcelo Ricardo Leitner <[email-masked]>
> Cc: Hannes Frederic Sowa <[email-masked]>

Acked-by: Hannes Frederic Sowa <[email-masked]>

Thanks,
Hannes