From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann Droneaud Subject: Re: [PATCH v3] IB/ipoib: Scatter-Gather support in connected mode Date: Mon, 11 May 2015 13:40:07 +0200 Message-ID: <1431344407.25060.29.camel@opteya.com> References: <1431338642-22812-1-git-send-email-yuval.shaia@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1431338642-22812-1-git-send-email-yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yuval Shaia Cc: john.sobecki-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, christian-x8YiTEMPTCFhl2p70BpVqQ@public.gmane.org, dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org Hi, Le lundi 11 mai 2015 =C3=A0 03:04 -0700, Yuval Shaia a =C3=A9crit : > By default, IPoIB-CM driver uses 64k MTU. Larger MTU gives better per= formance. > This MTU plus overhead puts the memory allocation for IP based packet= s at 32 > 4k pages (order 5), which have to be contiguous. > When the system memory under pressure, it was observed that allocatin= g 128k > contiguous physical memory is difficult and causes serious errors (su= ch as > system becomes unusable). >=20 > This enhancement resolve the issue by removing the physically contigu= ous memory > requirement using Scatter/Gather feature that exists in Linux stack. >=20 > With this fix Scatter-Gather will be supported also in connected mode= =2E >=20 > This change reverts the some of the change made in commit > e112373fd6aa280bd2cbc0d5cc3809115325a1be > ("IPoIB/cm: Reduce connected mode TX object size)". >=20 > The ability to use SG in IPoIB CM is possible because the coupling > between NETIF_F_SG and NETIF_F_CSUM was removed in commit > ec5f061564238892005257c83565a0b58ec79295 > ("net: Kill link between CSUM and SG features.") >=20 > Signed-off-by: Yuval Shaia > --- > v2: Enhance commit log message >=20 > I'd like to thank John Sobecki and > Christian Marie for helping me with reviewing t= his patch. > I will be glad if you can ACK it. >=20 > v3: Add an empty line to start a new paragraph and use 12 hex-digits = identifier Thanks, but you don't have to use the full commit identifier, 12 characters were enough. Anyway, you haven't addressed the comments embedded in the patch in my reply [1] to your v2 patch. [1] http://marc.info/?i=3D1431335754.25060.26.camel-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org http://mid.gmane.org/1431335754.25060.26.camel-RlY5vtjFyJ3QT0dZR+AlfA@public.gmane.org Regards. --=20 Yann Droneaud OPTEYA -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html