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Re: Intel's new rte_memcpy()
- From: Luke Gorrie <luke at snabb dot co>
- To: OndÅej BÃlka <neleai at seznam dot cz>
- Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, éå(åå) <ling dot ml at alibaba-inc dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Mon, 2 Feb 2015 10:00:13 +0100
- Subject: Re: Intel's new rte_memcpy()
- Authentication-results: sourceware.org; auth=none
- References: <CAA2XHbendDcfydewf2nrpPQkSsDWPdEH0SMsnqZAFsLF9q4Fzg at mail dot gmail dot com> <CAMe9rOpELuXQLvHQLLAeZitTTcz-xeg=ROoDm0dHe-fg4m-Jew at mail dot gmail dot com> <20150131184837 dot GA3539 at domone>
On 31 January 2015 at 19:48, OndÅej BÃlka <neleai@seznam.cz> wrote:
>
> On Fri, Jan 30, 2015 at 09:03:50AM -0800, H.J. Lu wrote:
> > On Fri, Jan 30, 2015 at 5:52 AM, Luke Gorrie <luke@snabb.co> wrote:
> > > Should networking application developers adopt Intel's custom
> > > implementation if (like me) they are absolutely dependent on good and
> > > consistent performance of memcpy on all recent hardware (>= Sandy
> > > Bridge) and Linux distributions? (and then -- what to do about
> > > memmove?)
> >
> Definitely not.
Thank you for the detailed feedback!
Questions... :-)
Is there a simple way that I can reproduce these benchmarks? (I am
curious in general and I would also like to run this on the two-socket
Xeon E5 machines that I test with.)
I would like to create relatively portable binaries that don't depend
on recent glibc releases. For this purpose I am tempted to reference
an older memcpy in my symbol table with this trick:
__asm__(".symver memcpy,memcpy@GLIBC_2.2.5");
Is that a reasonable idea? Is it likely to have a significant
performance cost on some platforms? (in practice will this make memcpy
act like memmove?)
Cheers!
-Luke