From: "Steve Wise" <swise@opengridcomputing.com>
To: "'Sagi Grimberg'" <sagi@grimberg.me>, <linux-nvme@lists.infradead.org>
Cc: <linux-block@vger.kernel.org>, <linux-rdma@vger.kernel.org>,
"'Christoph Hellwig'" <hch@lst.de>,
"'Keith Busch'" <keith.busch@intel.com>
Subject: RE: [PATCH RFC 0/4] restore polling to nvme-rdma
Date: Wed, 12 Dec 2018 10:37:59 -0600 [thread overview]
Message-ID: <02a201d49239$0b00f3f0$2102dbd0$@opengridcomputing.com> (raw)
In-Reply-To: <20181211233652.9705-1-sagi@grimberg.me>
Hey Sagi,
> Subject: [PATCH RFC 0/4] restore polling to nvme-rdma
>
> Add an additional queue mapping for polling queues that will
> host polling for latency critical I/O.
>
> One caveat is that we don't want these queues to be pure polling
> as we don't want to bother with polling for the initial nvmf connect
> I/O. Hence, introduce ib_change_cq_ctx that will modify the cq polling
> context from SOFTIRQ to DIRECT. Note that this function is not safe
> with inflight I/O so the caller must make sure not to call it without
> having all I/O quiesced (we also relax the ib_cq_completion_direct warning
> as we have a scenario that this can happen).
Is there no way to handle this in the core? Maybe have the polling context
transition to DIRECT when the queue becomes empty and before re-arming the
CQ? So ib_change_cq_ctx() would be called to indicate the change should
happen when it is safe to do so.
Just a thought..
next prev parent reply other threads:[~2018-12-12 16:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 23:36 [PATCH RFC 0/4] restore polling to nvme-rdma Sagi Grimberg
2018-12-11 23:36 ` [PATCH RFC 1/4] nvme-fabrics: allow user to pass in nr_poll_queues Sagi Grimberg
2018-12-11 23:36 ` [PATCH RFC 2/4] rdma: introduce ib_change_cq_ctx Sagi Grimberg
2018-12-11 23:36 ` [PATCH RFC 3/4] nvme-rdma: implement polling queue map Sagi Grimberg
2018-12-11 23:36 ` [PATCH RFC 4/4] nvme-multipath: disable polling for underlying namespace request queue Sagi Grimberg
2018-12-12 7:11 ` Christoph Hellwig
2018-12-12 7:19 ` Sagi Grimberg
2018-12-12 7:21 ` Christoph Hellwig
2018-12-12 7:29 ` Sagi Grimberg
2018-12-12 7:37 ` Christoph Hellwig
2018-12-11 23:36 ` [PATCH RFC nvme-cli 5/4] fabrics: pass in number of polling queues Sagi Grimberg
2018-12-12 0:27 ` Sagi Grimberg
2018-12-12 7:07 ` [PATCH RFC 0/4] restore polling to nvme-rdma Christoph Hellwig
2018-12-12 7:16 ` Sagi Grimberg
2018-12-12 8:09 ` Christoph Hellwig
2018-12-12 8:53 ` Sagi Grimberg
2018-12-12 14:05 ` Christoph Hellwig
2018-12-12 18:23 ` Sagi Grimberg
2018-12-12 16:37 ` Steve Wise [this message]
2018-12-12 18:05 ` Sagi Grimberg
2018-12-12 18:10 ` Steve Wise
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