Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756074AbZCYRwq (ORCPT ); Wed, 25 Mar 2009 13:52:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755266AbZCYRwi (ORCPT ); Wed, 25 Mar 2009 13:52:38 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:51049 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754534AbZCYRwh (ORCPT ); Wed, 25 Mar 2009 13:52:37 -0400 Date: Wed, 25 Mar 2009 13:52:33 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Chetan.Loke@Emulex.Com cc: peterz@infradead.org, mingo@elte.hu, mathieu.desnoyers@polymtl.ca, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, ltt-dev@lists.casi.polymtl.ca, fweisbec@gmail.com, jbaron@redhat.com, tglx@linutronix.de, rmk+lkml@arm.linux.org.uk, mhiramat@redhat.com, fche@redhat.com, haoki@redhat.com, t-nishiie@np.css.fujitsu.com, eduard.munteanu@linux360.ro Subject: RE: [patch 3/9] LTTng instrumentation tasklets In-Reply-To: Message-ID: References: <20090324155625.420966314@polymtl.ca> <20090324160148.238795468@polymtl.ca> <20090324175621.GE31117@elte.hu> <1237990678.7972.1094.camel@twins> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1996 Lines: 53 On Wed, 25 Mar 2009, Chetan.Loke@Emulex.Com wrote: > > > > -----Original Message----- > > From: Peter Zijlstra [mailto:peterz@infradead.org] > > Sent: Wednesday, March 25, 2009 10:18 AM > > To: Loke,Chetan > > Cc: mingo@elte.hu; mathieu.desnoyers@polymtl.ca; > > akpm@linux-foundation.org; linux-kernel@vger.kernel.org; > > ltt-dev@lists.casi.polymtl.ca; fweisbec@gmail.com; > > jbaron@redhat.com; tglx@linutronix.de; > > rmk+lkml@arm.linux.org.uk; mhiramat@redhat.com; > > fche@redhat.com; haoki@redhat.com; > > t-nishiie@np.css.fujitsu.com; rostedt@goodmis.org; > > eduard.munteanu@linux360.ro > > Subject: RE: [patch 3/9] LTTng instrumentation tasklets > > > > On Wed, 2009-03-25 at 06:52 -0700, Chetan.Loke@Emulex.Com wrote: > > > Quick question. I understand this is unrelated to this patch. So I > > > apologize in advance. > > > Ingo - you mentioned "tasklets are a legacy mechanism". Is there a > > > plan to phase them out ? Let me draw a small picture as to what's > > > bothering me. > > > > > > With the SR-IOV support if there are 'N' virtual functions > > then there > > > will be 'N' driver instances(actually N+1, 1 for the PF). If that > > > driver drains the responses in the interrupt context then all such > > > VF-instances could virtually block everyone else(because > > SR-IOV guys > > > might also have MSI-X enabled). > > > So now all such drivers should alter their Rx path.Driver's > > can queue > > > tasklets and can also get the performance they want. > > > > > > Any suggestions? > > > > Threaded interrupts? > > > > If we truly need to address performance and scalability for the SCSI-subsystem then we need something lightweight. Threaded interrupts are actually quite light. -- Steve -- 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/