From: Florian Westphal <fw@strlen.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Florian Westphal <fw@strlen.de>, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH v2 -next 2/2] netfilter: store rules per NUMA node instead of per cpu
Date: Fri, 29 May 2015 11:41:46 +0200 [thread overview]
Message-ID: <20150529094146.GH23992@breakpoint.cc> (raw)
In-Reply-To: <1432850655.7456.45.camel@edumazet-glaptop2.roam.corp.google.com>
Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Thu, 2015-05-28 at 23:52 +0200, Florian Westphal wrote:
> > Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > > Are we copying kernel text to each NUMA node ? ;)
> >
> > Beats me. I was under impression that cpu accessing memory on other node
> > takes access penalty, thats why I changed it to per node allocation.
>
> Well, it depends. If one core is busy while others are idle, then
> fetching data from 2 NUMA nodes is actually faster. (Some workloads are
> actually faster with 'random' NUMA interleaving)
>
> If you constrain all memory access being done from local node, then you
> might loose total bandwidth. In practice, intensive workloads will
> populate L1/L2/L3 cache, and actual memory location does not really
> matter.
OK; convinced. I'll kill the per numa part of the change, thanks Eric.
next prev parent reply other threads:[~2015-05-29 9:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-28 20:51 [PATCH v2 -next 1/2] netfilter: iptables: separate counters from iptables rules Florian Westphal
2015-05-28 20:51 ` [PATCH v2 -next 2/2] netfilter: store rules per NUMA node instead of per cpu Florian Westphal
2015-05-28 21:38 ` Eric Dumazet
2015-05-28 21:52 ` Florian Westphal
2015-05-28 22:04 ` Eric Dumazet
2015-05-29 9:41 ` Florian Westphal [this message]
2015-05-28 21:33 ` [PATCH v2 -next 1/2] netfilter: iptables: separate counters from iptables rules Eric Dumazet
2015-05-28 21:45 ` Florian Westphal
2015-05-28 21:54 ` Eric Dumazet
2015-05-29 10:05 ` Florian Westphal
2015-05-29 10:32 ` Eric Dumazet
2015-05-29 11:32 ` Patrick Schaaf
2015-06-05 12:28 ` Florian Westphal
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