Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757563Ab0FRIKu (ORCPT ); Fri, 18 Jun 2010 04:10:50 -0400 Received: from hera.kernel.org ([140.211.167.34]:51726 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757243Ab0FRIKs (ORCPT ); Fri, 18 Jun 2010 04:10:48 -0400 Message-ID: <4C1B29BF.7080404@kernel.org> Date: Fri, 18 Jun 2010 10:09:35 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.9) Gecko/20100317 Thunderbird/3.0.4 MIME-Version: 1.0 To: Andrew Morton CC: Andy Walls , Daniel Walker , mingo@elte.hu, linux-kernel@vger.kernel.org, jeff@garzik.org, rusty@rustcorp.com.au, cl@linux-foundation.org, dhowells@redhat.com, arjan@linux.intel.com, johannes@sipsolutions.net, oleg@redhat.com, axboe@kernel.dk Subject: Re: Overview of concurrency managed workqueue References: <1276551467-21246-1-git-send-email-tj@kernel.org> <4C17C598.7070303@kernel.org> <1276631037.6432.9.camel@c-dwalke-linux.qualcomm.com> <4C18BF40.40607@kernel.org> <1276694825.9309.12.camel@m0nster> <4C18D1FD.9060804@kernel.org> <1276695665.9309.17.camel@m0nster> <4C18D574.1040903@kernel.org> <1276697146.9309.27.camel@m0nster> <1276776066.2461.15.camel@localhost> <20100617161619.d3ebd73d.akpm@linux-foundation.org> <4C1B1D3F.8030509@kernel.org> <20100618003127.10d9e6c8.akpm@linux-foundation.org> In-Reply-To: <20100618003127.10d9e6c8.akpm@linux-foundation.org> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 18 Jun 2010 08:09:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1158 Lines: 28 Hello, On 06/18/2010 09:31 AM, Andrew Morton wrote: > On Fri, 18 Jun 2010 09:16:15 +0200 Tejun Heo wrote: > Nope. Consider a simple byte-at-a-time rx handler. The ISR grabs the > byte, stashes it away, bangs on the hardware a bit then signals > userspace to promptly start processing that byte. Very simple, > legitimate and a valid thing to do. > > Also the "interrupt" code might be running from a timer handler. Or it > might just be in process context, buried in a forest of locks and wants > to punt further processing into a separate process. Sure, there'll be cases which would be better served that way but things which fit neither the traditional interrupt handler nor the threaded one are in very small minority. I think having niche solutions for those niche problems would be far better than trying to engineer generic async mechanism to serve all of them. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/