From: Ming Lei <ming.lei@redhat.com> To: Keith Busch <kbusch@kernel.org> Cc: Sagi Grimberg <sagi@grimberg.me>, Long Li <longli@microsoft.com>, "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>, Jens Axboe <axboe@fb.com>, Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de> Subject: Re: [PATCH 2/2] nvme-pci: poll IO after batch submission for multi-mapping queue Date: Wed, 13 Nov 2019 11:57:48 +0800 Message-ID: <20191113035748.GD28701@ming.t460p> (raw) In-Reply-To: <20191113031702.GA25906@redsun51.ssa.fujisawa.hgst.com> On Wed, Nov 13, 2019 at 12:17:02PM +0900, Keith Busch wrote: > On Wed, Nov 13, 2019 at 11:05:20AM +0800, Ming Lei wrote: > > Threaded irq can't help Azure's performance, because Azure's nvme implementation > > applies aggressive interrupt coalescing. > > This sounds like QD1 latency is really awful if it's coalescing this way. > > Let me restate to ensure I understand how this patch addresses the > high-depth case: by polling during submission, a multi-threaded high > depth workload gets to carve up the number of CQEs handled by spreading > across more CPUs. Real hardware should see fewer completions per > interrupt, Right, cause submission's frequency is high enough. > but we should be able to recreate this issue by enabling > interrupt coalescing on a real NVMe. Yeah, I just tried it, and similar intx/s and throughput can be re-created on one real NVMe. Thanks, Ming _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme
next prev parent reply index Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-08 3:55 [PATCH 0/2] nvme-pci: improve IO performance via poll after batch submission Ming Lei 2019-11-08 3:55 ` [PATCH 1/2] nvme-pci: move sq/cq_poll lock initialization into nvme_init_queue Ming Lei 2019-11-08 4:12 ` Keith Busch 2019-11-08 7:09 ` Ming Lei 2019-11-08 3:55 ` [PATCH 2/2] nvme-pci: poll IO after batch submission for multi-mapping queue Ming Lei 2019-11-11 20:44 ` Christoph Hellwig 2019-11-12 0:33 ` Long Li 2019-11-12 1:35 ` Sagi Grimberg 2019-11-12 2:39 ` Ming Lei 2019-11-12 16:25 ` Hannes Reinecke 2019-11-12 16:49 ` Keith Busch 2019-11-12 17:29 ` Hannes Reinecke 2019-11-13 3:05 ` Ming Lei 2019-11-13 3:17 ` Keith Busch 2019-11-13 3:57 ` Ming Lei [this message] 2019-11-12 21:20 ` Long Li 2019-11-12 21:36 ` Keith Busch 2019-11-13 0:50 ` Long Li 2019-11-13 2:24 ` Ming Lei 2019-11-12 2:07 ` Ming Lei 2019-11-12 1:44 ` Sagi Grimberg 2019-11-12 9:56 ` Ming Lei 2019-11-12 17:35 ` Sagi Grimberg 2019-11-12 21:17 ` Long Li 2019-11-12 23:44 ` Jens Axboe 2019-11-13 2:47 ` Ming Lei 2019-11-12 18:11 ` Nadolski, Edmund 2019-11-13 13:46 ` Ming Lei
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