On Mon, Sep 9, 2013 at 11:51 PM, Markus Stockhausen <stockhau...@collogia.de> wrote: >> Von: Wendy Cheng [s.wendy.ch...@gmail.com] >> Gesendet: Montag, 9. September 2013 22:03 >> An: Markus Stockhausen >> Cc: linux-rdma@vger.kernel.org >> Betreff: Re: Strange NFS client ACK behaviour >> >> On Sun, Sep 8, 2013 at 11:24 AM, Markus Stockhausen >> <stockhau...@collogia.de> wrote: >> >> >> > we observed a performance drop in our IPoIB NFS backup >> >> > infrastructure since we switched to machines with newer >> >> > kernels. >> > >> >> Not sure how your backup infrastructure works but the symptoms seem to >> match with this discussion: >> http://www.spinics.net/lists/linux-nfs/msg38980.html >> >> If you know how to recompile nfs kmod, Trond's patch does worth a try. >> Or open an Ubuntu support ticket, let them build you a test kmod. >> >> -- Wendy > > Thanks for pointing into that direction. From my understanding this > patch goes into the NFS client side. I built a patched module for my > Fedora 19 client (3.10 kernel). Nevertheless the behaviour ist still > the same. If I get the patch right it is about forked childs that > access a page of a mmapped file round robin and the kernel issues > tons of write requests to the file. > > My case is only about ACK transmissions for a single writer. > > Markus >
So you have to go back to the drawing board :(. Have you tried to profile it ? http://oprofile.sourceforge.net/about/ -- Wendy -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
