From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
linux-scsi@vger.kernel.org,
Sathya Prakash <Sathya.Prakash@broadcom.com>,
Kashyap Desai <kashyap.desai@broadcom.com>,
linux-kernel@vger.kernel.org,
Chaitra Basappa <chaitra.basappa@broadcom.com>,
Sreekanth Reddy <sreekanth.reddy@broadcom.com>,
linux-nvme@lists.infradead.org
Subject: Re: [PATCH v4 00/14] mpt3sas driver NVMe support:
Date: Thu, 31 Aug 2017 23:22:44 -0400 [thread overview]
Message-ID: <yq13787w1a3.fsf@oracle.com> (raw)
In-Reply-To: <CA+RiK67f59U5Ss_Z2=veBRODtBSp1-4VTbosLkHkgaxY9XA6hQ@mail.gmail.com> (Suganath Prabu Subramani's message of "Thu, 31 Aug 2017 10:28:06 +0530")
Hi Suganath,
> Let me explain - NVME device fast path is possible in two ways. IEEE
> SGL and PRP SGL. Due to h/w constraint we choose IEEE SGL only for
> smaller IO size. Both above is true h/w Fast Path and no firmware
> involvement.
> Agree with you. We are planning to see if we can keep only simple Fast
> Path using only PRP.
That would be great, thank you!
> Currently there is no performance issue for UNMAP translation in FW.
Good!
>> And yet patch 4 circumvents that statement by adding support for
>> encapsulated commands to bypass the FW translation...
>
> This path is not due to performance reason. User wants to interact
> with NVME drive in native NVME command for management.
Patch 4 states:
"This encapsulated NVMe command is used by applications to send direct
NVMe commands to NVMe drives or for handling unmap where the translation
at controller/firmware level is having performance issues."
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2017-09-01 3:23 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-21 13:32 [PATCH v4 00/14] mpt3sas driver NVMe support: Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 01/14] mpt3sas: Update MPI Header Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 02/14] mpt3sas: Add nvme device support in slave alloc, target alloc and probe Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 03/14] mpt3sas: SGL to PRP Translation for I/Os to NVMe devices Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 04/14] mpt3sas: Added support for nvme encapsulated request message Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 05/14] mpt3sas: API 's to support NVMe drive addition to SML Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 06/14] mpt3sas: API's to remove nvme drive from sml Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 07/14] mpt3sas: Handle NVMe PCIe device related events generated from firmware Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 08/14] mpt3sas: Set NVMe device queue depth as 128 Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 09/14] mpt3sas: scan and add nvme device after controller reset Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 10/14] mpt3as: Add-Task-management-debug-info-for-NVMe-drives Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 11/14] mpt3sas: NVMe drive support for BTDHMAPPING ioctl command and log info Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 12/14] mpt3sas: Fix nvme drives checking for tlr Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 13/14] mpt3sas: Update mpt3sas driver version Suganath Prabu S
2017-08-21 13:32 ` [PATCH v4 14/14] mpt3sas: Fix sparse warning Suganath Prabu S
2017-08-23 2:18 ` [PATCH v4 00/14] mpt3sas driver NVMe support: Martin K. Petersen
2017-08-30 12:30 ` Suganath Prabu Subramani
2017-08-31 3:05 ` Martin K. Petersen
2017-08-31 4:58 ` Suganath Prabu Subramani
2017-09-01 3:22 ` Martin K. Petersen [this message]
2017-09-01 8:39 ` Suganath Prabu Subramani
2017-09-13 7:15 ` Suganath Prabu Subramani
2017-09-15 1:07 ` Martin K. Petersen
2017-09-18 10:39 ` Suganath Prabu Subramani
2017-09-25 20:22 ` Martin K. Petersen
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