Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763861AbZCYRhx (ORCPT ); Wed, 25 Mar 2009 13:37:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763678AbZCYRh3 (ORCPT ); Wed, 25 Mar 2009 13:37:29 -0400 Received: from emulex.emulex.com ([138.239.112.1]:63374 "EHLO emulex.emulex.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763700AbZCYRh1 convert rfc822-to-8bit (ORCPT ); Wed, 25 Mar 2009 13:37:27 -0400 From: Chetan.Loke@Emulex.Com To: CC: , , , , , , , , , , , , , , Date: Wed, 25 Mar 2009 10:37:20 -0700 Subject: RE: [patch 3/9] LTTng instrumentation tasklets Thread-Topic: [patch 3/9] LTTng instrumentation tasklets Thread-Index: AcmtVIuhXSFJkV1OQxOJCrZQf+Wq0gAG4Wmw Message-ID: References: <20090324155625.420966314@polymtl.ca> <20090324160148.238795468@polymtl.ca> <20090324175621.GE31117@elte.hu> <1237990678.7972.1094.camel@twins> In-Reply-To: <1237990678.7972.1094.camel@twins> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginalArrivalTime: 25 Mar 2009 17:37:23.0490 (UTC) FILETIME=[5B34D020:01C9AD70] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1804 Lines: 44 > -----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.-- 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/