From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>,
linux-rdma@vger.kernel.org, sagig@dev.mellanox.co.il,
axboe@fb.com, linux-scsi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/9] IB: add a proper completion queue abstraction
Date: Mon, 23 Nov 2015 14:28:22 -0700 [thread overview]
Message-ID: <20151123212822.GE6062@obsidianresearch.com> (raw)
In-Reply-To: <56537F59.4080708@sandisk.com>
On Mon, Nov 23, 2015 at 01:04:25PM -0800, Bart Van Assche wrote:
> Considerable time ago the send queue in the SRP initiator driver was
> modified from signaled to non-signaled to reduce the number of interrupts
> triggered by the SRP initiator driver. The SRP initiator driver polls the
> send queue every time before a SCSI command is sent to the target. I think
> this is a pattern that is also useful for other ULP's so I'm not convinced
> that ib_process_cq_direct() should be deprecated :-)
As I explained, that is a fine idea, but I can't see how SRP is able
to correctly do sendq flow control without spinning on the poll, which
it does not do.
I'm guessing SRP is trying to drive sendq flow control from the recv
side, like NFS was. This is wrong and should not be part of the common
API.
Does that make sense?
Jason
next prev parent reply other threads:[~2015-11-23 21:28 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-13 13:46 add a proper completion queue abstraction Christoph Hellwig
2015-11-13 13:46 ` [PATCH 1/9] move blk_iopoll to limit and make it generally available Christoph Hellwig
[not found] ` <1447422410-20891-2-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-13 15:23 ` Or Gerlitz
[not found] ` <CAJ3xEMgj2ycv61K38ZOowTRbrri_UhQgBcaKT0ZnnMHiBrmL5A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-11-14 7:02 ` Christoph Hellwig
[not found] ` <20151114070200.GA27738-jcswGhMUV9g@public.gmane.org>
2015-11-15 8:48 ` Sagi Grimberg
[not found] ` <564846E9.9070301-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-15 9:04 ` Or Gerlitz
[not found] ` <CAJ3xEMgvttM1D3bePz0CWhZAZ3gCSQsf_qgmq9Ny4gzK5d0bXw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-11-15 13:16 ` Sagi Grimberg
2015-11-15 12:51 ` Christoph Hellwig
2015-11-13 19:19 ` Bart Van Assche
2015-11-14 7:02 ` Christoph Hellwig
2015-11-17 17:16 ` Bart Van Assche
2015-11-17 17:27 ` Bart Van Assche
2015-11-18 13:58 ` Christoph Hellwig
2015-11-13 13:46 ` [PATCH 2/9] IB: add a proper completion queue abstraction Christoph Hellwig
[not found] ` <1447422410-20891-3-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-13 18:25 ` Jason Gunthorpe
[not found] ` <20151113182513.GB21808-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2015-11-13 19:57 ` Bart Van Assche
2015-11-13 22:06 ` Jason Gunthorpe
[not found] ` <20151113220636.GA32133-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2015-11-14 7:13 ` Christoph Hellwig
[not found] ` <20151114071344.GE27738-jcswGhMUV9g@public.gmane.org>
2015-11-23 20:37 ` Jason Gunthorpe
2015-11-23 21:04 ` Bart Van Assche
2015-11-23 21:28 ` Jason Gunthorpe [this message]
2015-11-23 21:54 ` Bart Van Assche
2015-11-23 22:18 ` Jason Gunthorpe
2015-11-23 22:33 ` Bart Van Assche
2015-11-23 23:06 ` Jason Gunthorpe
[not found] ` <B24F4DDE-709A-4D2D-8B26-4E83325DBB1A@asomi.com>
2015-11-24 0:00 ` Jason Gunthorpe
[not found] ` <20151124000011.GA9301-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2015-11-24 0:34 ` Tom Talpey
[not found] ` <5653B0AD.7090402-CLs1Zie5N5HQT0dZR+AlfA@public.gmane.org>
2015-11-24 0:40 ` Jason Gunthorpe
2015-11-24 2:35 ` Caitlin Bestler
[not found] ` <5653CCF0.7050501-DpaxOq6QOWMAvxtiuMwx3w@public.gmane.org>
2015-11-24 7:03 ` Jason Gunthorpe
[not found] ` <20151124070301.GA23597-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2015-11-24 12:52 ` Tom Talpey
2015-11-14 7:08 ` Christoph Hellwig
2015-11-23 20:01 ` Jason Gunthorpe
[not found] ` <20151123200136.GA5640-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2015-11-23 20:57 ` Christoph Hellwig
2015-11-17 17:52 ` Bart Van Assche
[not found] ` <564B697A.2020601-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2015-11-18 7:55 ` Sagi Grimberg
[not found] ` <564C2F01.6020407-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-18 18:20 ` Bart Van Assche
2015-11-20 10:16 ` Christoph Hellwig
2015-11-20 16:50 ` Bart Van Assche
2015-11-22 9:51 ` Sagi Grimberg
2015-11-22 10:13 ` Christoph Hellwig
[not found] ` <20151122101308.GA12189-jcswGhMUV9g@public.gmane.org>
2015-11-22 10:36 ` Sagi Grimberg
[not found] ` <56519A90.5010502-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-22 13:23 ` Christoph Hellwig
[not found] ` <20151122132352.GA14154-jcswGhMUV9g@public.gmane.org>
2015-11-22 14:57 ` Sagi Grimberg
2015-11-22 16:55 ` Bart Van Assche
2015-11-18 14:00 ` Christoph Hellwig
2015-11-15 9:40 ` Sagi Grimberg
[not found] ` <564852F2.5080602-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-15 12:55 ` Christoph Hellwig
[not found] ` <20151115125501.GB2218-jcswGhMUV9g@public.gmane.org>
2015-11-15 13:21 ` Sagi Grimberg
2015-11-13 13:46 ` [PATCH 3/9] IB: add a helper to safely drain a QP Christoph Hellwig
[not found] ` <1447422410-20891-4-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-13 16:16 ` Steve Wise
[not found] ` <56460CC4.3030001-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2015-11-14 7:05 ` Christoph Hellwig
2015-11-18 11:32 ` Sagi Grimberg
[not found] ` <564C61C3.3050307-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-18 14:06 ` Christoph Hellwig
[not found] ` <20151118140645.GI18820-jcswGhMUV9g@public.gmane.org>
2015-11-18 15:21 ` Steve Wise
2015-11-15 9:34 ` Sagi Grimberg
[not found] ` <564851BB.1020004-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-16 16:38 ` Steve Wise
[not found] ` <564A067B.8030504-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2015-11-16 18:30 ` Steve Wise
2015-11-16 18:37 ` Sagi Grimberg
[not found] ` <564A2270.1040004-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-16 19:03 ` Steve Wise
2015-11-17 8:54 ` Sagi Grimberg
2015-11-23 10:28 ` Sagi Grimberg
2015-11-23 10:35 ` Sagi Grimberg
2015-11-23 14:33 ` 'Christoph Hellwig'
[not found] ` <5652EC00.8010705-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
2015-11-23 14:48 ` Steve Wise
2015-11-23 14:44 ` Steve Wise
2015-11-17 17:06 ` Bart Van Assche
[not found] ` <564B5E7D.9030309-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2015-11-18 7:59 ` Sagi Grimberg
[not found] ` <1447422410-20891-1-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-13 13:46 ` [PATCH 4/9] srpt: chain RDMA READ/WRITE requests Christoph Hellwig
2015-11-18 1:17 ` Bart Van Assche
2015-11-18 9:15 ` Sagi Grimberg
2015-11-18 16:32 ` Bart Van Assche
[not found] ` <564CA83B.4060403-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2015-11-20 10:20 ` Christoph Hellwig
[not found] ` <564BD1AF.60200-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2015-11-18 14:06 ` Christoph Hellwig
2015-11-13 13:46 ` [PATCH 5/9] srpt: use the new CQ API Christoph Hellwig
[not found] ` <1447422410-20891-6-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-17 18:22 ` Bart Van Assche
2015-11-17 19:38 ` Bart Van Assche
[not found] ` <564B8248.7050407-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
2015-11-18 14:03 ` Christoph Hellwig
2015-11-13 13:46 ` [PATCH 6/9] srp: " Christoph Hellwig
[not found] ` <1447422410-20891-7-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-17 19:56 ` Bart Van Assche
2015-11-18 14:03 ` Christoph Hellwig
2015-11-13 13:46 ` [PATCH 7/9] IB/iser: Use a dedicated descriptor for login Christoph Hellwig
[not found] ` <1447422410-20891-8-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-15 9:14 ` Or Gerlitz
2015-11-13 13:46 ` [PATCH 8/9] IB/iser: Use helper for container_of Christoph Hellwig
2015-11-13 13:46 ` [PATCH 9/9] IB/iser: Convert to CQ abstraction Christoph Hellwig
[not found] ` <1447422410-20891-10-git-send-email-hch-jcswGhMUV9g@public.gmane.org>
2015-11-15 9:21 ` Or Gerlitz
[not found] <20151124100839.48b52fb35c6f209c51bccbb9807b6df0.f113bf890f.wbe@email24.secureserver.net>
[not found] ` <20151124100839.48b52fb35c6f209c51bccbb9807b6df0.f113bf890f.wbe-wCzC33v8tqnShzhksYgB+AejPw4fNl8p@public.gmane.org>
2015-11-24 17:52 ` [PATCH 2/9] IB: add a proper completion queue abstraction Jason Gunthorpe
[not found] ` <56552132.7090701@asomi.com>
[not found] ` <56552132.7090701-DpaxOq6QOWMAvxtiuMwx3w@public.gmane.org>
2015-11-25 6:21 ` Jason Gunthorpe
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