From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [Qemu-devel] [PATCH v2] posix-aio-compat: fix latency issues Date: Tue, 23 Aug 2011 16:10:17 +0200 Message-ID: <4E53B4C9.3070906@siemens.com> References: <1313294689-21572-1-git-send-email-avi@redhat.com> <4E5291DF.1070603@siemens.com> <4E539FA9.3010507@codemonkey.ws> <4E53A4E4.1090807@siemens.com> <4E53B2D8.7080608@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Kevin Wolf , Stefan Hajnoczi , Avi Kivity , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" To: Anthony Liguori Return-path: Received: from david.siemens.de ([192.35.17.14]:25146 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755589Ab1HWOK0 (ORCPT ); Tue, 23 Aug 2011 10:10:26 -0400 In-Reply-To: <4E53B2D8.7080608@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: On 2011-08-23 16:02, Anthony Liguori wrote: > On 08/23/2011 08:02 AM, Jan Kiszka wrote: >> On 2011-08-23 14:40, Anthony Liguori wrote: >>> You should be able to just use an eventfd or pipe. >>> >>> Better yet, we should look at using GThreadPool to replace posix-aio-compat. >> >> When interacting with the thread pool is part of some time-critical path >> (easily possible with a real-time Linux guest), general-purpose >> implementations like what glib offers are typically out of the game. >> They do not provide sufficient customizability, specifically control >> over their internal synchronization and allocation policies. That >> applies to the other rather primitive glib threading and locking >> services as well. > > We can certainly enhance glib. glib is a cross platform library. I Do you want to carry forked glib bits in QEMU? > don't see a compelling reason to invent a new cross platform library > just for QEMU especially if the justification is future features, not > current features. Tweaking affinity of aio threads is already a current requirement. And we already have a working threading and locking system. One that is growing beyond glib's level of support quickly (think of RCU). Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux