From: David Miller <davem@davemloft.net>
To: herbert@gondor.apana.org.au
Cc: krkumar2@in.ibm.com, jarkao2@gmail.com, netdev@vger.kernel.org
Subject: Re: [RFC] [PATCH] Don't run __qdisc_run() on a stopped TX queue
Date: Mon, 27 Jul 2009 21:21:07 -0700 (PDT) [thread overview]
Message-ID: <20090727.212107.161491585.davem@davemloft.net> (raw)
In-Reply-To: <20090728024813.GA23992@gondor.apana.org.au>
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 28 Jul 2009 10:48:13 +0800
> On Mon, Jul 27, 2009 at 07:28:44PM -0700, David Miller wrote:
>>
>> There is a locking benefit even for non-default qdiscs.
>>
>> Instead of two choke points (qdisc lock and queue lock) there
>> is now only one (qdisc lock) and consdiering the cost of
>> things like setting up IOMMU mappings and hitting chip
>> registers the qdisc lock is the shortest held of the two.
>
> But only one CPU can process a given qdisc at one time so I don't
> see why there is a second choke point if you use a single queue
> with a non-default qdisc.
Good point, but this only suggests that we might want to undo that
queue runner exclusivity state bit for this case especially when we
know that we are feeding a multiqueue device.
next prev parent reply other threads:[~2009-07-28 4:21 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-20 7:46 [RFC] [PATCH] Don't run __qdisc_run() on a stopped TX queue Krishna Kumar
2009-07-24 8:30 ` Jarek Poplawski
2009-07-24 8:37 ` Herbert Xu
2009-07-24 10:31 ` Krishna Kumar2
2009-07-25 3:24 ` Herbert Xu
2009-07-25 11:04 ` Jarek Poplawski
2009-07-25 11:12 ` Herbert Xu
2009-07-25 11:53 ` Jarek Poplawski
2009-07-28 2:28 ` David Miller
2009-07-28 2:48 ` Herbert Xu
2009-07-28 4:21 ` David Miller [this message]
2009-07-28 6:43 ` Jarek Poplawski
2009-07-28 8:03 ` Herbert Xu
2009-07-28 8:37 ` Jarek Poplawski
2009-07-28 8:44 ` Herbert Xu
2009-07-28 9:02 ` Jarek Poplawski
2009-07-28 10:53 ` Herbert Xu
2009-07-28 11:24 ` Jarek Poplawski
2009-07-28 11:43 ` Krishna Kumar2
2009-07-28 11:48 ` Herbert Xu
2009-07-28 12:24 ` Krishna Kumar2
2009-07-28 20:02 ` David Miller
2009-07-28 7:12 ` Herbert Xu
2009-07-28 19:59 ` David Miller
2009-07-29 0:44 ` Herbert Xu
2009-07-29 1:06 ` David Miller
2009-07-29 1:25 ` Herbert Xu
2009-07-29 1:34 ` David Miller
2009-07-29 2:12 ` Herbert Xu
2009-07-29 2:22 ` David Miller
2009-07-29 2:38 ` Herbert Xu
2009-07-29 3:15 ` Herbert Xu
2009-08-04 3:15 ` David Miller
2009-07-29 11:04 ` Jarek Poplawski
2009-07-29 11:11 ` Herbert Xu
2009-07-29 11:26 ` Jarek Poplawski
2009-07-29 12:30 ` Herbert Xu
2009-07-29 12:47 ` Jarek Poplawski
2009-07-29 13:08 ` Krishna Kumar2
2009-07-29 19:26 ` Jarek Poplawski
2009-07-29 13:28 ` Krishna Kumar2
2009-07-24 12:46 ` Eric Dumazet
2009-07-24 14:54 ` Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090727.212107.161491585.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=herbert@gondor.apana.org.au \
--cc=jarkao2@gmail.com \
--cc=krkumar2@in.ibm.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).