From: Jesper Dangaard Brouer <brouer@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
David Miller <davem@davemloft.net>,
Alexander Duyck <alexander.duyck@gmail.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Daniel Borkmann <borkmann@iogearbox.net>,
Marek Majkowski <marek@cloudflare.com>,
Hannes Frederic Sowa <hannes@stressinduktion.org>,
Florian Westphal <fw@strlen.de>, Paolo Abeni <pabeni@redhat.com>,
John Fastabend <john.r.fastabend@intel.com>,
brouer@redhat.com
Subject: Re: Optimizing instruction-cache, more packets at each stage
Date: Fri, 15 Jan 2016 15:00:25 +0100 [thread overview]
Message-ID: <20160115150025.13a5db04@redhat.com> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CCC6613@AcuExch.aculab.com>
On Fri, 15 Jan 2016 13:36:04 +0000
David Laight <David.Laight@ACULAB.COM> wrote:
> From: Jesper Dangaard Brouer
> > Sent: 15 January 2016 13:22
> ...
> > I want to do some instruction-cache level optimizations.
> >
> > What do I mean by that...
> >
> > The kernel network stack code path (a packet travels) is obviously
> > larger than the instruction-cache (icache). Today, every packet
> > travel individually through the network stack, experiencing the exact
> > same icache misses (as the previous packet).
> ...
>
> Is that actually true for modern server processors that have large i-cache.
> While the total size of the networking code may well be larger, that
> part used for transmitting data packets will be much be smaller and
> could easily fit in the icache.
Yes, exactly. That is what I'm betting on. If I can split it into
stages (e.g. part used for transmitting) that fits into icache then I
should see a win.
The icache is still quite small 32Kb on modern server processors. I
don't know if smaller embedded processors also have icache and how
large they are. I speculate this approach would also be a benefit for
them (if they have icache).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
Author of http://www.iptv-analyzer.org
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2016-01-15 14:00 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-15 13:22 Optimizing instruction-cache, more packets at each stage Jesper Dangaard Brouer
2016-01-15 13:32 ` Hannes Frederic Sowa
2016-01-15 14:17 ` Jesper Dangaard Brouer
2016-01-15 13:36 ` David Laight
2016-01-15 14:00 ` Jesper Dangaard Brouer [this message]
2016-01-15 14:38 ` Felix Fietkau
2016-01-18 11:54 ` Jesper Dangaard Brouer
2016-01-18 17:01 ` Eric Dumazet
2016-01-25 0:08 ` Florian Fainelli
2016-01-15 20:47 ` David Miller
2016-01-18 10:27 ` Jesper Dangaard Brouer
2016-01-18 16:24 ` David Miller
2016-01-20 22:20 ` Or Gerlitz
2016-01-20 23:02 ` Eric Dumazet
2016-01-20 23:27 ` Tom Herbert
2016-01-21 11:27 ` Jesper Dangaard Brouer
2016-01-21 12:49 ` Or Gerlitz
2016-01-21 13:57 ` Jesper Dangaard Brouer
2016-01-21 18:56 ` David Miller
2016-01-21 22:45 ` Or Gerlitz
2016-01-21 22:59 ` David Miller
2016-01-21 16:38 ` Eric Dumazet
2016-01-21 18:54 ` David Miller
2016-01-24 14:28 ` Jesper Dangaard Brouer
2016-01-24 14:44 ` Michael S. Tsirkin
2016-01-24 17:28 ` John Fastabend
2016-01-25 13:15 ` Bypass at packet-page level (Was: Optimizing instruction-cache, more packets at each stage) Jesper Dangaard Brouer
2016-01-25 17:09 ` Tom Herbert
2016-01-25 17:50 ` John Fastabend
2016-01-25 21:32 ` Tom Herbert
2016-01-25 21:58 ` John Fastabend
2016-01-25 22:10 ` Jesper Dangaard Brouer
2016-01-27 20:47 ` Jesper Dangaard Brouer
2016-01-27 21:56 ` Alexei Starovoitov
2016-01-28 9:52 ` Jesper Dangaard Brouer
2016-01-28 12:54 ` Eric Dumazet
2016-01-28 13:25 ` Eric Dumazet
2016-01-28 16:43 ` Tom Herbert
2016-01-28 2:50 ` Tom Herbert
2016-01-28 9:25 ` Jesper Dangaard Brouer
2016-01-28 12:45 ` Eric Dumazet
2016-01-28 16:37 ` Tom Herbert
2016-01-28 16:43 ` Eric Dumazet
2016-01-28 17:04 ` Jesper Dangaard Brouer
2016-01-24 20:09 ` Optimizing instruction-cache, more packets at each stage Tom Herbert
2016-01-24 21:41 ` John Fastabend
2016-01-24 23:50 ` Tom Herbert
2016-01-21 12:23 ` Jesper Dangaard Brouer
2016-01-21 16:38 ` Tom Herbert
2016-01-21 17:48 ` Eric Dumazet
2016-01-22 12:33 ` Jesper Dangaard Brouer
2016-01-22 14:33 ` Eric Dumazet
2016-01-22 17:07 ` Tom Herbert
2016-01-22 17:17 ` Jesper Dangaard Brouer
2016-02-02 16:13 ` Or Gerlitz
2016-02-02 16:37 ` Eric Dumazet
2016-01-18 16:53 ` Eric Dumazet
2016-01-18 17:36 ` Tom Herbert
2016-01-18 17:49 ` Jesper Dangaard Brouer
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