From: David Miller <davem@davemloft.net>
To: herbert@gondor.apana.org.au
Cc: hadi@cyberus.ca, kaber@trash.net, netdev@vger.kernel.org,
johannes@sipsolutions.net, linux-wireless@vger.kernel.org
Subject: Re: [PATCH 20/31]: pkt_sched: Perform bulk of qdisc destruction in RCU.
Date: Mon, 21 Jul 2008 09:51:24 -0700 (PDT) [thread overview]
Message-ID: <20080721.095124.89249903.davem@davemloft.net> (raw)
In-Reply-To: <20080721164306.GA13131@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 22 Jul 2008 00:43:06 +0800
> So let's assume that these flows have been distributed uniformly
> by both the RX hash and the TX hash such that each queue is handling
> ~250 flows. If the TX hash does not match the result produced by
> the RX hash, you're going to get a hell lot of contention once you
> get into the NIC driver on the TX side.
How so? If the TX hash is well distributed, which it should be,
it is at least going to approximate the distribution provided by
the RX hash.
> The benefit as far as I can see is that this would allow a packet's
> entire journey through Linux to stay on exactly one CPU. There will
> be zero memory written by multiple CPUs as far as that packet is
> concerned.
So will the existing one, enough of the time for it to matter,
and yes even on a router or firewall.
At least this is my belief :-)
next prev parent reply other threads:[~2008-07-21 16:51 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-17 12:17 [PATCH 20/31]: pkt_sched: Perform bulk of qdisc destruction in RCU David Miller
[not found] ` <20080717.051726.226040470.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-17 13:03 ` Patrick McHardy
[not found] ` <487F4327.1000107-dcUjhNyLwpNeoWH0uzbU5w@public.gmane.org>
2008-07-17 13:12 ` David Miller
2008-07-17 13:48 ` Patrick McHardy
[not found] ` <487F4DA6.6010009-dcUjhNyLwpNeoWH0uzbU5w@public.gmane.org>
2008-07-17 22:36 ` David Miller
[not found] ` <20080717.153609.142867331.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-17 23:58 ` Patrick McHardy
2008-07-17 13:35 ` jamal
2008-07-17 14:02 ` Patrick McHardy
[not found] ` <487F50EC.80008-dcUjhNyLwpNeoWH0uzbU5w@public.gmane.org>
2008-07-17 22:24 ` David Miller
[not found] ` <20080717.152447.89672084.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-17 23:48 ` Patrick McHardy
2008-07-18 13:10 ` jamal
2008-07-18 13:27 ` jamal
2008-07-18 21:05 ` David Miller
2008-07-20 15:16 ` jamal
2008-07-20 17:25 ` David Miller
[not found] ` <20080720.102534.246150854.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-20 17:34 ` Tomas Winkler
[not found] ` <1ba2fa240807201034u1fbe3343tdcc858f7772d2b39-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-07-20 17:35 ` David Miller
2008-07-20 22:32 ` jamal
2008-07-20 23:59 ` David Miller
2008-07-21 2:20 ` jamal
2008-07-21 11:20 ` jamal
2008-07-21 16:45 ` David Miller
2008-07-21 11:58 ` Herbert Xu
[not found] ` <E1KKu2D-0002kd-00-XQvu0L+U/CjiRBuR/1fSEKKkPtS2pBon@public.gmane.org>
2008-07-21 13:08 ` jamal
2008-07-21 13:19 ` Herbert Xu
2008-07-21 13:56 ` jamal
2008-07-21 13:58 ` Herbert Xu
[not found] ` <20080721135846.GA11543-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-07-21 15:09 ` David Miller
[not found] ` <20080721.080901.214889979.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-21 15:22 ` Herbert Xu
2008-07-21 15:26 ` David Miller
[not found] ` <20080721.082627.128593651.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-21 16:16 ` Herbert Xu
[not found] ` <20080721161616.GA12938-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-07-21 16:25 ` David Miller
2008-07-21 16:43 ` Herbert Xu
2008-07-21 16:51 ` David Miller [this message]
[not found] ` <20080721.095124.89249903.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-21 17:02 ` Herbert Xu
[not found] ` <20080721170233.GA13417-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-07-21 17:08 ` David Miller
[not found] ` <20080721.100821.38432201.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-07-21 17:11 ` Herbert Xu
2008-08-22 6:56 ` Herbert Xu
2008-08-22 7:16 ` David Miller
[not found] ` <20080822.001620.141235108.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-08-22 7:41 ` Herbert Xu
[not found] ` <20080822074115.GB25615-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-08-22 10:42 ` David Miller
[not found] ` <20080822.034217.135152551.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2008-08-22 10:47 ` Herbert Xu
2008-08-22 13:52 ` jamal
[not found] ` <20080822065655.GA18471-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-08-22 13:43 ` jamal
2008-07-21 17:35 ` David Miller
2008-07-18 17:10 ` Roland Dreier
[not found] ` <adaljzz6ruq.fsf-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>
2008-07-20 14:58 ` jamal
2008-07-20 14:32 ` Herbert Xu
2008-07-20 17:20 ` David Miller
2008-07-20 14:20 ` Herbert Xu
[not found] ` <E1KKZmE-0000ty-00-XQvu0L+U/CjiRBuR/1fSEKKkPtS2pBon@public.gmane.org>
2008-07-20 15:35 ` jamal
2008-07-21 0:11 ` Herbert Xu
[not found] ` <20080721001119.GA6515-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-07-21 2:33 ` jamal
2008-07-21 3:17 ` Herbert Xu
2008-07-21 11:14 ` jamal
2008-07-21 11:36 ` Herbert Xu
[not found] ` <20080721113600.GA10322-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org>
2008-07-21 11:39 ` jamal
2008-07-19 3:59 ` David Miller
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