<div dir="ltr">+sachin.</div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Sep 27, 2016 at 11:23 AM, Raghavendra Gowdappa <span dir="ltr"><<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class=""><br>
<br>
----- Original Message -----<br>
> From: "Ric Wheeler" <<a href="mailto:rwheeler@redhat.com">rwheeler@redhat.com</a>><br>
> To: "Raghavendra Gowdappa" <<a href="mailto:rgowdapp@redhat.com">rgowdapp@redhat.com</a>>, "Saravanakumar Arumugam" <<a href="mailto:sarumuga@redhat.com">sarumuga@redhat.com</a>><br>
> Cc: "Gluster Devel" <<a href="mailto:gluster-devel@gluster.org">gluster-devel@gluster.org</a>>, "Ben Turner" <<a href="mailto:bturner@redhat.com">bturner@redhat.com</a>>, "Ben England"<br>
> <<a href="mailto:bengland@redhat.com">bengland@redhat.com</a>><br>
> Sent: Tuesday, September 27, 2016 10:51:48 AM<br>
> Subject: Re: [Gluster-devel] libgfapi zero copy write - application in samba, nfs-ganesha<br>
><br>
> On 09/27/2016 07:56 AM, Raghavendra Gowdappa wrote:<br>
> > +Manoj, +Ben turner, +Ben England.<br>
> ><br>
> > @Perf-team,<br>
> ><br>
> > Do you think the gains are significant enough, so that smb and nfs-ganesha<br>
> > team can start thinking about consuming this change?<br>
> ><br>
> > regards,<br>
> > Raghavendra<br>
><br>
> This is a large gain but I think that we might see even larger gains (a lot<br>
> depends on how we implement copy offload :)).<br>
<br>
</span>Can you elaborate on what you mean "copy offload"? If it is the way we avoid a copy in gfapi (from application buffer), following is the workflow:<br>
<br>
<commit><br>
<br>
Work flow of zero copy write operation:<br>
------------------------------<wbr>--------<br>
<br>
1) Application requests a buffer of specific size. A new buffer is<br>
allocated from iobuf pool, and this buffer is passed on to application.<br>
Achieved using "glfs_get_buffer"<br>
<br>
2) Application writes into the received buffer, and passes that to<br>
libgfapi, and libgfapi in turn passes the same buffer to underlying<br>
translators. This avoids a memcpy in glfs write<br>
Achieved using "glfs_zero_write"<br>
<br>
3) Once the write operation is complete, Application must take the<br>
responsibilty of freeing the buffer.<br>
Achieved using "glfs_free_buffer"<br>
<br>
</commit><br>
<br>
Do you've any suggestions/improvements on this? I think Shyam mentioned an alternative approach (for zero-copy readv I think), let me look up at that too.<br>
<br>
regards,<br>
Raghavendra<br>
<div class="HOEnZb"><div class="h5"><br>
><br>
> Worth looking at how we can make use of it.<br>
><br>
> thanks!<br>
><br>
> Ric<br>
><br>
> ><br>
> > ----- Original Message -----<br>
> >> From: "Saravanakumar Arumugam" <<a href="mailto:sarumuga@redhat.com">sarumuga@redhat.com</a>><br>
> >> To: "Gluster Devel" <<a href="mailto:gluster-devel@gluster.org">gluster-devel@gluster.org</a>><br>
> >> Sent: Monday, September 26, 2016 7:18:26 PM<br>
> >> Subject: [Gluster-devel] libgfapi zero copy write - application in samba,<br>
> >> nfs-ganesha<br>
> >><br>
> >> Hi,<br>
> >><br>
> >> I have carried out "basic" performance measurement with zero copy write<br>
> >> APIs.<br>
> >> Throughput of zero copy write is 57 MB/sec vs default write 43 MB/sec.<br>
> >> ( I have modified Ben England's gfapi_perf_test.c for this. Attached the<br>
> >> same<br>
> >> for reference )<br>
> >><br>
> >> We would like to hear how samba/ nfs-ganesha who are libgfapi users can<br>
> >> make<br>
> >> use of this.<br>
> >> Please provide your comments. Refer attached results.<br>
> >><br>
> >> Zero copy in write patch: <a href="http://review.gluster.org/#/c/14784/" rel="noreferrer" target="_blank">http://review.gluster.org/#/c/<wbr>14784/</a><br>
> >><br>
> >> Thanks,<br>
> >> Saravana<br>
><br>
><br>
______________________________<wbr>_________________<br>
Gluster-devel mailing list<br>
<a href="mailto:Gluster-devel@gluster.org">Gluster-devel@gluster.org</a><br>
<a href="http://www.gluster.org/mailman/listinfo/gluster-devel" rel="noreferrer" target="_blank">http://www.gluster.org/<wbr>mailman/listinfo/gluster-devel</a><br>
</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature">Raghavendra G<br></div>
</div>