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From: swise@opengridcomputing.com (Steve Wise)
Subject: [PATCH RFC 0/2] 8K Inline Support
Date: Wed, 9 May 2018 08:38:05 -0700	[thread overview]
Message-ID: <cover.1525880285.git.swise@opengridcomputing.com> (raw)

For small nvmf write IO over the rdma transport, it is advantagous to
make use of inline mode to avoid the latency of the target issuing an
rdma read to fetch the data.  Currently inline is used for <= 4K writes.
8K, though, requires the rdma read.  For iWARP transports additional
latency is incurred because the target mr of the read must be registered
with remote write access.  By allowing 2 pages worth of inline payload,
I see a reduction in 8K nvmf write latency of anywhere from 2-7 usecs
depending on the RDMA transport..

Is this a worthwhile change?  I think it is.  Please comment!

Thanks,

Steve

Steve Wise (2):
  nvme-rdma: Support 8K inline
  nvmet-rdma: Support 8K inline

 drivers/nvme/host/rdma.c   | 21 +++++++++++++++------
 drivers/nvme/target/rdma.c |  4 ++--
 2 files changed, 17 insertions(+), 8 deletions(-)

-- 
1.8.3.1

             reply	other threads:[~2018-05-09 15:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-09 15:38 Steve Wise [this message]
2018-05-09 14:31 ` [PATCH RFC 1/2] nvme-rdma: Support 8K inline Steve Wise
2018-05-09 16:55   ` Parav Pandit
2018-05-09 19:28     ` Steve Wise
2018-05-11  6:48   ` Christoph Hellwig
2018-05-14 18:33     ` Steve Wise
2018-05-09 14:34 ` [PATCH RFC 2/2] nvmet-rdma: " Steve Wise
2018-05-14 10:16   ` Max Gurtovoy
2018-05-14 14:58     ` Steve Wise
2018-05-09 18:46 ` [PATCH RFC 0/2] 8K Inline Support Steve Wise
2018-05-11  6:19 ` Christoph Hellwig

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