From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 0/7] Intel IOMMU scalability improvements Date: Mon, 4 Jan 2016 18:35:10 +0100 Message-ID: <20160104173510.GT18805@8bytes.org> References: <20151228161421.GA27829@cs.technion.ac.il> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20151228161421.GA27829-FrESSTt7Abv7r6psnUbsSmZHpeb/A1Y/@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Adam Morrison Cc: serebrin-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, dan-FrESSTt7Abv7r6psnUbsSmZHpeb/A1Y/@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, omer-FrESSTt7Abv7r6psnUbsSmZHpeb/A1Y/@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi Adam, On Mon, Dec 28, 2015 at 06:14:21PM +0200, Adam Morrison wrote: > This patchset improves the scalability of the Intel IOMMU code by > resolving two spinlock bottlenecks, yielding up to ~10x performance > improvement and approaching iommu=off performance. > > For example, here's the throughput obtained by 16 memcached instances > running on a 16-core Sandy Bridge system, accessed using memslap on > another machine that has iommu=off, using the default memslap config > (64-byte keys, 1024-byte values, and 10%/90% SET/GET ops): > > stock iommu=off: > 1,088,996 memcached transactions/sec (=100%, median of 10 runs). > stock iommu=on: > 123,760 memcached transactions/sec (=11%). > [perf: 43.56% 0.86% memcached [kernel.kallsyms] [k] _raw_spin_lock_irqsave] > patched iommu=on: > 1,067,586 memcached transactions/sec (=98%). > [perf: 0.75% 0.75% memcached [kernel.kallsyms] [k] _raw_spin_lock_irqsave] > Thanks for the patches, the results look pretty impressive. I'll have a closer look at your changes this week. Joerg