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From: David Miller <davem@davemloft.net>
To: alexander.duyck@gmail.com
Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org
Subject: Re: [PATCH 00/16] Remove the ipv4 routing cache
Date: Wed, 25 Jul 2012 16:17:32 -0700 (PDT)	[thread overview]
Message-ID: <20120725.161732.91008692477078715.davem@davemloft.net> (raw)
In-Reply-To: <CAKgT0UdcqE52WFCT-t2om0SN3Yq5GqiwN+JbwCcnBv4LDOB6BQ@mail.gmail.com>

From: Alexander Duyck <alexander.duyck@gmail.com>
Date: Wed, 25 Jul 2012 16:02:45 -0700

> Since your patches are in I have started to re-run my tests. I am
> seeing a significant drop in throughput with 8 flows which I expected,
> however it looks like one of the biggest issues I am seeing is that
> the dst_hold and dst_release calls seem to be causing some serious
> cache thrash.  I was at 12.5Mpps w/ 8 flows before the patches, after
> your patches it drops to 8.3Mpps.

Yes, this is something we knew would start happening.

One idea is to make cached dsts be per-cpu in the nexthops.

> I am also seeing routing fail periodically.

Every 30 seconds by chance? :-)

> I will be moving at rates listed above and suddenly drop to single
> digits packets per second.  When this occurs the trace completely
> changes and __write_lock_failed jumps to over 90% of the CPU cycles.

It's probably happening when the nexthop ARP entry expires.

  reply	other threads:[~2012-07-25 23:17 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-20 21:25 [PATCH 00/16] Remove the ipv4 routing cache David Miller
2012-07-20 22:05 ` Eric Dumazet
2012-07-20 22:42   ` Eric Dumazet
2012-07-20 22:50     ` David Miller
2012-07-20 22:54       ` David Miller
2012-07-20 23:13         ` David Miller
2012-07-21  5:40           ` Eric Dumazet
2012-07-22  7:47 ` Vijay Subramanian
2012-07-22 19:42   ` David Miller
2012-07-23  0:39 ` David Miller
2012-07-23  7:15   ` Eric Dumazet
2012-07-23 17:54     ` Paweł Staszewski
2012-07-23 20:10       ` David Miller
2012-07-26 17:02       ` Eric Dumazet
2012-07-25 23:02 ` Alexander Duyck
2012-07-25 23:17   ` David Miller [this message]
2012-07-25 23:39     ` David Miller
2012-07-26  0:54       ` David Miller
2012-07-26  2:30         ` Alexander Duyck
2012-07-26  5:32           ` David Miller
2012-07-26  8:13         ` Eric Dumazet
2012-07-26  8:18           ` David Miller
2012-07-26  8:27             ` Eric Dumazet
2012-07-26  8:47               ` David Miller
2012-07-26  9:12                 ` Eric Dumazet
2012-07-26 17:18                 ` Alexander Duyck
2012-07-26 17:30                   ` Eric Dumazet
2012-07-26 17:36                     ` Eric Dumazet
2012-07-26 17:43                       ` Eric Dumazet
2012-07-26 17:48                         ` Eric Dumazet
2012-07-26 18:26                           ` Alexander Duyck
2012-07-26 21:06                             ` David Miller
2012-07-26 22:03                               ` Alexander Duyck
2012-07-26 22:13                                 ` Stephen Hemminger
2012-07-26 22:19                                   ` Eric Dumazet
2012-07-26 22:48                                   ` David Miller
2012-07-26 22:53                                 ` David Miller
2012-07-27  2:14                                   ` Alexander Duyck
2012-07-27  3:08                                     ` David Miller
2012-07-27  6:02                                       ` David Miller
2012-07-27 10:01                                         ` Eric Dumazet
2012-07-27 14:53                                           ` Eric W. Biederman
2012-07-27 15:12                                             ` Eric Dumazet
2012-07-27 16:23                                               ` Eric W. Biederman
2012-07-27 16:28                                                 ` Eric Dumazet
2012-07-27 19:06                                                   ` Alexander Duyck
2012-07-28  4:15                                         ` David Miller
2012-07-28  5:45                                           ` Alexander Duyck
2012-07-26 18:06                         ` Alexander Duyck
2012-07-26 21:00                         ` David Miller
2012-07-26 20:59                   ` David Miller

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