From mboxrd@z Thu Jan 1 00:00:00 1970 From: martin.petersen@oracle.com (Martin K. Petersen) Date: Tue, 22 Aug 2017 22:18:06 -0400 Subject: [PATCH v4 00/14] mpt3sas driver NVMe support: In-Reply-To: <1503322344-5900-1-git-send-email-suganath-prabu.subramani@broadcom.com> (Suganath Prabu S.'s message of "Mon, 21 Aug 2017 19:02:10 +0530") References: <1503322344-5900-1-git-send-email-suganath-prabu.subramani@broadcom.com> Message-ID: Suganath, > mpt3sas: SGL to PRP Translation for I/Os to NVMe devices I'm still confused about this patch. - I don't understand why you go through all these hoops to decide whether to use PRPs or IEEE scatterlists. If the firmware translation is slow, why even bother with the SG format in the first place? Set the max I/O size to match MDTS and you're done. - What's the benefit of using SG for regular I/O commands? - If the unmap translation in firmware is slow, why don't you translate WRITE SAME/w UNMAP set to DSM DEALLOCATE without requiring applications to do encapsulated passthrough? Also make sure you attribute your patches correctly (From: root ). And you don't need that long CC: list. Just send the patch series to linux-scsi at vger.kernel.org. Thanks! -- Martin K. Petersen Oracle Linux Engineering From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH v4 00/14] mpt3sas driver NVMe support: Date: Tue, 22 Aug 2017 22:18:06 -0400 Message-ID: References: <1503322344-5900-1-git-send-email-suganath-prabu.subramani@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1503322344-5900-1-git-send-email-suganath-prabu.subramani@broadcom.com> (Suganath Prabu S.'s message of "Mon, 21 Aug 2017 19:02:10 +0530") Sender: linux-kernel-owner@vger.kernel.org To: Suganath Prabu S Cc: jejb@kernel.org, hch@infradead.org, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, Sathya.Prakash@broadcom.com, kashyap.desai@broadcom.com, linux-kernel@vger.kernel.org, chaitra.basappa@broadcom.com, sreekanth.reddy@broadcom.com, linux-nvme@lists.infradead.org List-Id: linux-scsi@vger.kernel.org Suganath, > mpt3sas: SGL to PRP Translation for I/Os to NVMe devices I'm still confused about this patch. - I don't understand why you go through all these hoops to decide whether to use PRPs or IEEE scatterlists. If the firmware translation is slow, why even bother with the SG format in the first place? Set the max I/O size to match MDTS and you're done. - What's the benefit of using SG for regular I/O commands? - If the unmap translation in firmware is slow, why don't you translate WRITE SAME/w UNMAP set to DSM DEALLOCATE without requiring applications to do encapsulated passthrough? Also make sure you attribute your patches correctly (From: root ). And you don't need that long CC: list. Just send the patch series to linux-scsi@vger.kernel.org. Thanks! -- Martin K. Petersen Oracle Linux Engineering