From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: [PATCH v2 0/4] arbitrary sg lists support Date: Thu, 20 Apr 2017 14:30:46 +0300 Message-ID: References: <1492098977-5231-1-git-send-email-maxg@mellanox.com> <1492101079.5176.9.camel@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1492101079.5176.9.camel-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bart Van Assche , "hch-jcswGhMUV9g@public.gmane.org" , "maxg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org" , "keith.busch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" Cc: "vladimirk-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org" List-Id: linux-rdma@vger.kernel.org >> This patch adds an arbitrary sg list support to NVMEoF host for >> capable devices (such as RDMA CX4/CX5 HCAs). >> During the review we decided to add an helper function to ib_core >> that will be used by ULPs in order to avoid code duplication. > > Hello Max, > > A question that is not related to the ULP drivers touched by this patch series: > some time ago registration of sg-lists with gaps was disabled in the SRP > initiator because arbitrary sg-lists triggered CQE dumps in combination with the > mlx5 driver. Does this mean that this issue has been resolved? If so, what mlx5 > driver and/or firmware version are needed to reenable arbitrary sg-list support > in the SRP initiator? I'm concerned about the fact that the SRP issue wasn't resolved. There might be a bug hiding there. Max, Leon, my recollection was that the error syndrome you saw with SRP described "too much sgls for a single mr". If this is true, then I still think we need a different device capability for it. I'm even thinking we need to remove gaps support from iSER until this is addressed. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: sagi@grimberg.me (Sagi Grimberg) Date: Thu, 20 Apr 2017 14:30:46 +0300 Subject: [PATCH v2 0/4] arbitrary sg lists support In-Reply-To: <1492101079.5176.9.camel@sandisk.com> References: <1492098977-5231-1-git-send-email-maxg@mellanox.com> <1492101079.5176.9.camel@sandisk.com> Message-ID: >> This patch adds an arbitrary sg list support to NVMEoF host for >> capable devices (such as RDMA CX4/CX5 HCAs). >> During the review we decided to add an helper function to ib_core >> that will be used by ULPs in order to avoid code duplication. > > Hello Max, > > A question that is not related to the ULP drivers touched by this patch series: > some time ago registration of sg-lists with gaps was disabled in the SRP > initiator because arbitrary sg-lists triggered CQE dumps in combination with the > mlx5 driver. Does this mean that this issue has been resolved? If so, what mlx5 > driver and/or firmware version are needed to reenable arbitrary sg-list support > in the SRP initiator? I'm concerned about the fact that the SRP issue wasn't resolved. There might be a bug hiding there. Max, Leon, my recollection was that the error syndrome you saw with SRP described "too much sgls for a single mr". If this is true, then I still think we need a different device capability for it. I'm even thinking we need to remove gaps support from iSER until this is addressed.