From: Robert Sanford <rsanford@prolexic.com>
To: Dmitry Vyal <dmitryvyal@gmail.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] How to fight forwarding performance regression on large mempool sizes.
Date: Fri, 20 Sep 2013 10:41:08 -0400 [thread overview]
Message-ID: <CAFmpvUOdxajdkiOR3B8FW8M-C_zxwXjmaYX2YCzA88_njtB1uw@mail.gmail.com> (raw)
In-Reply-To: <523BEFA3.4070209@gmail.com>
It might be interesting to see that start/end address of the 256K-item (256
* 1024 * 2240 = 560 MB) mbuf memory pool. Maybe it's the first size that
straddles two 1GB pages.
Perhaps you should try a tool that reports cache misses, TLB misses, and
related statistics. I don't know much about this area, yet, but this looks
like a good starting place:
http://software.intel.com/en-us/articles/intel-performance-counter-monitor-a-better-way-to-measure-cpu-utilization
--
Regards,
Robert
On Fri, Sep 20, 2013 at 2:48 AM, Dmitry Vyal <dmitryvyal@gmail.com> wrote:
> On 09/19/2013 11:39 PM, Robert Sanford wrote:
>
>> Hi Dmitry,
>>
>> The biggest drop-off seems to be from size 128K to 256K. Are you using
>> 1GB huge pages already (rather than 2MB)?
>>
>> I would think that it would not use over 1GB until you ask for 512K mbufs
>> or more.
>>
>>
> Hi Robert,
>
> Yes, I've been using 1GB pages for a while. My L3 cache is 20MB and mbufs
> are 2240 bytes of size. So something strange indeed happens then we move
> from ~200MB to ~400MB. Any ideas?
>
> Regards,
> Dmitry
>
>
next prev parent reply other threads:[~2013-09-20 14:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-19 7:50 Dmitry Vyal
2013-09-19 19:39 ` Robert Sanford
2013-09-19 19:43 ` Venkatesan, Venky
2013-09-20 6:50 ` Dmitry Vyal
2013-09-20 6:48 ` Dmitry Vyal
2013-09-20 14:41 ` Robert Sanford [this message]
2013-09-20 15:34 ` Robert Sanford
2013-09-22 19:03 ` Dmitry Vyal
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