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From: Eelco Chaudron <echaudro@redhat.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: dev@dpdk.org, jingjing.wu@intel.com
Subject: Re: [dpdk-dev] [PATCH] app/testpmd: adds mlockall() to fix pages
Date: Thu, 14 Sep 2017 09:22:38 +0200	[thread overview]
Message-ID: <2ff0680b-b73f-fd1f-9f41-caa38a13bcde@redhat.com> (raw)
In-Reply-To: <4147502.SWF1kaKTU5@xps>

On 13/09/17 11:39, Thomas Monjalon wrote:
> 12/09/2017 15:08, Eelco Chaudron:
>> Call the mlockall() function, to attempt to lock all of its process
>> memory into physical RAM, and preventing the kernel from paging any
>> of its memory to disk.
>>
>> When using testpmd for performance testing, depending on the code path
>> taken, we see a couple of page faults in a row. These faults effect
>> the overall drop-rate of testpmd. On Linux the mlockall() call will
>> prefault all the pages of testpmd (and the DPDK libraries if linked
>> dynamically), even without LD_BIND_NOW.
> Does it work on FreeBSD?
I do not have a FreeBSD setup, but from the documentation I've read the 
call is supported by FreeBSD.
If some one has a working setup, please give this patch a quick try.
> Is there any drawback?
> Do we need to add an option for it?
The only drawback I can think of is that with this change memory 
phyiscal memory is consumed as pages are pre-loaded.
For testpmd (just loaded not doing anything) this is 2MB vs 35MB of 
memory used. I do not think this yields an extra option.

  reply	other threads:[~2017-09-14  7:22 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-12 13:08 Eelco Chaudron
2017-09-12 14:50 ` Aaron Conole
2017-09-12 20:14   ` Thomas Monjalon
2017-09-12 20:29     ` Aaron Conole
2017-09-12 22:13       ` Thomas Monjalon
2017-09-13  8:55         ` Eelco Chaudron
2017-09-13 12:28         ` Aaron Conole
2017-09-13  9:15 ` Maxime Coquelin
2017-09-13  9:39 ` Thomas Monjalon
2017-09-14  7:22   ` Eelco Chaudron [this message]
2017-09-19  7:28     ` Olivier MATZ
2017-09-21 12:24       ` Eelco Chaudron
2017-09-25  7:53         ` Olivier MATZ
2017-09-29  7:59           ` Eelco Chaudron
2017-09-29  8:07 ` Sergio Gonzalez Monroy
2017-09-29  8:15   ` Eelco Chaudron
2017-09-29  9:27     ` Sergio Gonzalez Monroy

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