From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Tom Herbert" <therbert@google.com>,
"Linux Netdev List" <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Alexander Duyck" <alexander.h.duyck@intel.com>,
"Toke Høiland-Jørgensen" <toke@toke.dk>,
"Florian Westphal" <fw@strlen.de>,
"Jamal Hadi Salim" <jhs@mojatatu.com>,
"Dave Taht" <dave.taht@gmail.com>,
"John Fastabend" <john.r.fastabend@intel.com>,
"Daniel Borkmann" <dborkman@redhat.com>,
"Hannes Frederic Sowa" <hannes@stressinduktion.org>,
brouer@redhat.com
Subject: Re: [PATCH net-next] dql: dql_queued() should write first to reduce bus transactions
Date: Fri, 26 Sep 2014 10:47:32 +0200 [thread overview]
Message-ID: <20140926104732.625b4141@redhat.com> (raw)
In-Reply-To: <1411711496.16953.92.camel@edumazet-glaptop2.roam.corp.google.com>
On Thu, 25 Sep 2014 23:04:56 -0700
Eric Dumazet <eric.dumazet@gmail.com> wrote:
[...]
>
> It turned out the problem was caused by compiler trying to be
> smart, but involving a bad MESI transaction :
>
[...]
>
> I got an incredible 10 % gain [1] by making sure cpu do not attempt
> to get the cache line in Shared mode, but directly requests for
> ownership.
[...]
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> ---
I'm very impressed - thank you Eric for finding this!!!
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Sr. Network Kernel Developer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2014-09-26 8:47 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-24 16:10 [net-next PATCH 0/1 V4] qdisc bulk dequeuing and utilizing delayed tailptr updates Jesper Dangaard Brouer
2014-09-24 16:12 ` [net-next PATCH 1/1 V4] qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE Jesper Dangaard Brouer
2014-09-24 17:23 ` Eric Dumazet
2014-09-24 17:58 ` Jesper Dangaard Brouer
2014-09-24 18:34 ` Tom Herbert
2014-09-24 19:22 ` Eric Dumazet
2014-09-25 2:12 ` Eric Dumazet
2014-09-25 2:38 ` Tom Herbert
2014-09-25 2:58 ` Dave Taht
2014-09-26 18:06 ` Eric Dumazet
2014-09-25 23:40 ` Eric Dumazet
2014-09-26 6:04 ` [PATCH net-next] dql: dql_queued() should write first to reduce bus transactions Eric Dumazet
2014-09-26 8:47 ` Jesper Dangaard Brouer [this message]
2014-09-26 11:06 ` Hannes Frederic Sowa
2014-09-26 12:02 ` Eric Dumazet
2014-09-28 21:43 ` David Miller
2014-09-26 9:23 ` [net-next PATCH 1/1 V4] qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE David Laight
2014-09-26 13:16 ` David Laight
2014-09-26 13:38 ` Eric Dumazet
2014-09-24 22:13 ` Jamal Hadi Salim
2014-09-25 8:25 ` Jesper Dangaard Brouer
2014-09-25 12:48 ` Jamal Hadi Salim
2014-09-25 14:40 ` Tom Herbert
2014-09-25 14:57 ` Jesper Dangaard Brouer
2014-09-25 15:05 ` Tom Herbert
2014-09-25 15:23 ` Jesper Dangaard Brouer
2014-09-25 15:58 ` Tom Herbert
2014-09-29 20:23 ` Jesper Dangaard Brouer
2014-09-29 20:14 ` Jesper Dangaard Brouer
2014-09-25 15:12 ` Eric Dumazet
2014-09-25 13:52 ` Dave Taht
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