From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f182.google.com (mail-ie0-f182.google.com [209.85.223.182]) by kanga.kvack.org (Postfix) with ESMTP id 58C496B0032 for ; Fri, 24 Apr 2015 10:04:14 -0400 (EDT) Received: by iecrt8 with SMTP id rt8so84084578iec.0 for ; Fri, 24 Apr 2015 07:04:14 -0700 (PDT) Received: from resqmta-ch2-10v.sys.comcast.net (resqmta-ch2-10v.sys.comcast.net. [2001:558:fe21:29:69:252:207:42]) by mx.google.com with ESMTPS id 5si9790783icu.79.2015.04.24.07.04.13 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 24 Apr 2015 07:04:13 -0700 (PDT) Date: Fri, 24 Apr 2015 09:04:13 -0500 (CDT) From: Christoph Lameter Subject: Re: Interacting with coherent memory on external devices In-Reply-To: <20150423154229.GA2399@gmail.com> Message-ID: References: <20150421214445.GA29093@linux.vnet.ibm.com> <20150422000538.GB6046@gmail.com> <20150422131832.GU5561@linux.vnet.ibm.com> <20150422170737.GB4062@gmail.com> <1429756592.4915.23.camel@kernel.crashing.org> <20150423154229.GA2399@gmail.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Jerome Glisse Cc: Benjamin Herrenschmidt , "Paul E. McKenney" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jglisse@redhat.com, mgorman@suse.de, aarcange@redhat.com, riel@redhat.com, airlied@redhat.com, aneesh.kumar@linux.vnet.ibm.com, Cameron Buschardt , Mark Hairgrove , Geoffrey Gerfin , John McKenna , akpm@linux-foundation.org On Thu, 23 Apr 2015, Jerome Glisse wrote: > The numa code we have today for CPU case exist because it does make > a difference but you keep trying to restrict GPU user to a workload > that is specific. Go talk to people doing physic, biology, data > mining, CAD most of them do not care about latency. They have not > hard deadline to meet with their computation. They just want things > to compute as fast as possible and programming to be as easy as it > can get. I started working on the latency issues a long time ago because performance of those labs was restricted by OS processing. A noted problem was SLABs scanning of its objects every 2 seconds which caused pretty significant performance regressions due to the delay of the computation in individual threads. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org