From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@infradead.org (Christoph Hellwig) Date: Wed, 16 May 2018 23:50:49 -0700 Subject: [PATCH] nvme: remove cq check after submission In-Reply-To: <20180516212010.GC20223@localhost.localdomain> References: <20180516212010.GC20223@localhost.localdomain> Message-ID: <20180517065049.GA30079@infradead.org> On Wed, May 16, 2018@03:20:10PM -0600, Keith Busch wrote: > On Wed, May 16, 2018@01:58:08PM -0600, Jens Axboe wrote: > > We always check the completion queue after submitting, but in my testing > > this isn't a win even on DRAM/xpoint devices. In some cases it's > > actually worse. Kill it. > > Right, this was on my todo list. Agreed it's not helping anything. > Applied to nvme-4.18. While I agree in general didn't we have a case where this caused a regression last time it came up? Not that I'd complain if it goes away.. But more importantly we could split q_lock into a sq_lock and cq_lock now, which might bring real benefits.