From: David Miller <davem@davemloft.net>
To: tglx@linutronix.de
Cc: peter.p.waskiewicz.jr@intel.com, linux-kernel@vger.kernel.org,
arjan@linux.jf.intel.com, mingo@elte.hu, yong.zhang0@gmail.com,
netdev@vger.kernel.org
Subject: Re: [PATCH v2] irq: Add node_affinity CPU masks for smarter irqbalance hints
Date: Tue, 24 Nov 2009 09:57:03 -0800 (PST) [thread overview]
Message-ID: <20091124.095703.107687163.davem@davemloft.net> (raw)
In-Reply-To: <alpine.LFD.2.00.0911241151360.24119@localhost.localdomain>
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 24 Nov 2009 12:07:35 +0100 (CET)
> And what does the kernel do with this information and why are we not
> using the existing device/numa_node information ?
It's a different problem space Thomas.
If the device lives on NUMA node X, we still end up wanting to
allocate memory resources (RX ring buffers) on other NUMA nodes on a
per-queue basis.
Otherwise a network card's forwarding performance is limited by the
memory bandwidth of a single NUMA node, and on a multiqueue cards we
therefore fare much better by allocating each device RX queue's memory
resources on a different NUMA node.
It is this NUMA usage that PJ is trying to export somehow to userspace
so that irqbalanced and friends can choose the IRQ cpu masks more
intelligently.
next prev parent reply other threads:[~2009-11-24 17:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-24 9:35 Peter P Waskiewicz Jr
2009-11-24 11:07 ` Thomas Gleixner
2009-11-24 17:57 ` David Miller [this message]
2009-11-24 21:56 ` Thomas Gleixner
2009-11-24 22:05 ` Peter P Waskiewicz Jr
2009-11-24 22:23 ` Thomas Gleixner
2009-11-30 17:24 ` Peter P Waskiewicz Jr
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=20091124.095703.107687163.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=arjan@linux.jf.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=netdev@vger.kernel.org \
--cc=peter.p.waskiewicz.jr@intel.com \
--cc=tglx@linutronix.de \
--cc=yong.zhang0@gmail.com \
/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
all inboxes | Powered by JetHome®