From: Marc Sune <marc.sune@bisdn.de>
To: dev@dpdk.org
Subject: Re: [dpdk-dev] TX performance regression caused by the mbuf cachline split
Date: Tue, 12 May 2015 02:38:33 +0200 [thread overview]
Message-ID: <55514B89.5090100@bisdn.de> (raw)
In-Reply-To: <55514927.6090704@bisdn.de>
On 12/05/15 02:28, Marc Sune wrote:
>
>
> On 12/05/15 01:18, Paul Emmerich wrote:
>> Found a really simple solution that almost restores the original
>> performance: just add a prefetch on alloc. For some reason, I assumed
>> that this was already done since the troublesome commit I
>> investigated mentioned something about prefetching... I guess the
>> commit referred to the hardware prefetcher in the CPU.
>>
>> Adding an explicit prefetch command in the mbuf alloc function gives
>> a throughput of 12.7/10.35 Mpps in my benchmark with the
>> simple/full-featured tx path.
>>
>> DPDK 1.7.1 was at 14.1/10.7 Mpps. I guess I can live with that, since
>> I'm primarily interested in the full-featured path and the drop from
>> 10.7 to ~10.4 was due to another change.
>
> Maybe a stupid question;
>
> Does the performance of v1.7.1 also improve if you backport this patch
> to it?
Self answered... split was done in 1.8, so it is indeed stupid.
Marc
>
> Marc
>
>>
>> Patch: https://github.com/dpdk-org/dpdk/pull/2
>> I also sent an email to the mailing list.
>>
>> I also think that the rx-path could also benefit from prefetching
>> somewhere.
>>
>>
>> Paul
>>
>
next prev parent reply other threads:[~2015-05-12 0:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-11 0:14 Paul Emmerich
2015-05-11 9:13 ` Luke Gorrie
2015-05-11 10:16 ` Paul Emmerich
2015-05-11 22:32 ` Paul Emmerich
2015-05-11 23:18 ` Paul Emmerich
2015-05-12 0:28 ` Marc Sune
2015-05-12 0:38 ` Marc Sune [this message]
2015-05-13 9:03 ` Ananyev, Konstantin
2016-02-15 19:15 ` Paul Emmerich
2016-02-19 12:31 ` Olivier MATZ
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