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From: keith.busch@intel.com (Keith Busch)
Subject: bad IOPS when running multiple btest/fio in parallel
Date: Fri, 12 Oct 2018 08:39:21 -0600	[thread overview]
Message-ID: <20181012143921.GA15177@localhost.localdomain> (raw)
In-Reply-To: <1539319463418.78556@marvell.com>

On Fri, Oct 12, 2018@04:44:22AM +0000, Yao Lin wrote:
> Today I changed to a much simpler setup and the same issue persists.
> 
> Directly connect 2 PCs (identical hardware) with a pair of 100G rNICs. Create a null block device on the target PC and configure it as the NVMeOF target. So, there is no switch or SSD in this setup. And this is a single FIO, not the 4 FIO in parallel I mentioned earlier.
> 
> Start fio test against that null block device from the host, the best IOPS is 1550K. That's the best IOPS after I try out many different QD, # of job, and CPU affinity setting. Run the same fio test on the target, I get 2250K IOPS (it jumps to 3650K when I increased the number of threads). ?
> 
> So it seems to me that Linux NVMe stack is quite good and can support 100Gb/s + throughput. But the same can not be said of the NVMeOF stack. Any tuning possible?

You're sure it's the software stack? Need to check your CPU utilization to
see if that's a possibility.

  reply	other threads:[~2018-10-12 14:39 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-12  4:44 bad IOPS when running multiple btest/fio in parallel Yao Lin
2018-10-12 14:39 ` Keith Busch [this message]
2018-10-12 15:37   ` [EXT] " Yao Lin
2018-10-12 15:49 ` Bart Van Assche
2018-10-12 16:02   ` [EXT] " Yao Lin
2018-10-15  7:50     ` Sagi Grimberg
  -- strict thread matches above, loose matches on Subject: below --
2018-10-10 21:52 Yao Lin
2018-10-15  7:55 ` Sagi Grimberg

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