Messages in this thread | | | Date | Wed, 25 Mar 2009 13:52:33 -0400 (EDT) | From | Steven Rostedt <> | Subject | RE: [patch 3/9] LTTng instrumentation tasklets |
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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
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