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From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>,
	Max Gurtuvoy <maxg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Subject: Re: [PATCH v2 1/3] nvme-rdma: don't suppress send completions
Date: Thu, 9 Nov 2017 10:18:58 +0100	[thread overview]
Message-ID: <20171109091858.GA16966@lst.de> (raw)
In-Reply-To: <20171108100616.26605-2-sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>

On Wed, Nov 08, 2017 at 12:06:14PM +0200, Sagi Grimberg wrote:
> The entire completions suppress mechanism is currently
> broken because the HCA might retry a send operation
> (due to dropped ack) after the nvme transaction has completed.
> 
> In order to handle this, we signal all send completions (besides
> async event which is not racing anything).

Oh well, so much for all these unsignalled completion optimizations..

So in which cases do unsignalled completions work at all?  Seems like
we need to fix up a lot of other ULPs as well.

Looks fine:

Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>

> -	 */
> -	if (nvme_rdma_queue_sig_limit(queue) || flush)
> -		wr.send_flags |= IB_SEND_SIGNALED;
> +	wr.send_flags = IB_SEND_SIGNALED;

But..  Is there any benefit in just setting IB_SIGNAL_ALL_WR on the QP?
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  parent reply	other threads:[~2017-11-09  9:18 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-08 10:06 [PATCH v2 0/3] Fix request completion holes Sagi Grimberg
     [not found] ` <20171108100616.26605-1-sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-08 10:06   ` [PATCH v2 1/3] nvme-rdma: don't suppress send completions Sagi Grimberg
     [not found]     ` <20171108100616.26605-2-sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-09  9:18       ` Christoph Hellwig [this message]
     [not found]         ` <20171109091858.GA16966-jcswGhMUV9g@public.gmane.org>
2017-11-09 11:08           ` Sagi Grimberg
     [not found]             ` <921c4331-9456-3783-423a-9c5c5e405131-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20  8:18               ` Christoph Hellwig
     [not found]                 ` <20171120081809.GB27552-jcswGhMUV9g@public.gmane.org>
2017-11-20  8:33                   ` Sagi Grimberg
     [not found]                     ` <4ac0bc2e-498b-0fc1-4e30-7ff76bd036f1-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20  9:32                       ` Christoph Hellwig
2017-11-08 10:06   ` [PATCH v2 2/3] nvme-rdma: don't complete requests before a send work request has completed Sagi Grimberg
     [not found]     ` <20171108100616.26605-3-sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-09  9:21       ` Christoph Hellwig
     [not found]         ` <20171109092110.GB16966-jcswGhMUV9g@public.gmane.org>
2017-11-09 11:14           ` Sagi Grimberg
     [not found]             ` <0f368bc9-2e9f-4008-316c-46b85661a274-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20  8:31               ` Christoph Hellwig
     [not found]                 ` <20171120083130.GC27552-jcswGhMUV9g@public.gmane.org>
2017-11-20  8:37                   ` Sagi Grimberg
     [not found]                     ` <384d8a51-aa2f-5954-c9fd-a0c88d7e5364-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20  8:41                       ` Christoph Hellwig
     [not found]                         ` <20171120084102.GA28456-jcswGhMUV9g@public.gmane.org>
2017-11-20  9:04                           ` Sagi Grimberg
2017-11-20  9:28                           ` Sagi Grimberg
     [not found]                             ` <58bdc9c0-f98e-9d9f-f81e-fbed572f922e-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20 10:49                               ` Christoph Hellwig
     [not found]                                 ` <20171120104921.GA31309-jcswGhMUV9g@public.gmane.org>
2017-11-20 11:12                                   ` Sagi Grimberg
     [not found]                                     ` <df9c9545-7c00-328b-9f98-535d8e889715-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-20 11:16                                       ` Christoph Hellwig
2017-11-08 10:06   ` [PATCH v2 3/3] nvme-rdma: wait for local invalidation before completing a request Sagi Grimberg
     [not found]     ` <20171108100616.26605-4-sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-09  9:39       ` Christoph Hellwig
2017-11-13 22:10   ` [PATCH v2 0/3] Fix request completion holes Doug Ledford
     [not found]     ` <1510611044.3735.49.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-11-16 15:39       ` Sagi Grimberg
     [not found]         ` <e89f72c6-12ce-c149-c81e-f3adb43a8e9e-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2017-11-16 15:58           ` Doug Ledford
2017-11-20  7:37           ` Christoph Hellwig
     [not found]             ` <20171120073755.GA2236-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2017-11-20  8:33               ` Sagi Grimberg

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