From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Lalancette Subject: Re: [UNTESTED] KVM: do not call kvm_set_irq from irq disabled section Date: Fri, 23 Apr 2010 09:02:06 -0400 Message-ID: <4BD19A4E.2020402@redhat.com> References: <201004211548.12824.sheng.yang@intel.com> <20100421155840.GA22052@amt.cnet> <20100421171227.GB10744@redhat.com> <20100421173734.GA27425@amt.cnet> <20100421175848.GB2455@redhat.com> <20100421182911.GA28343@amt.cnet> <20100421183839.GC2455@redhat.com> <20100422164038.GA1117@amt.cnet> <20100422181130.GD2455@redhat.com> <20100422194030.GA4616@amt.cnet> <20100422195514.GE2455@redhat.com> <4BD17F0D.5070201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Marcelo Tosatti , "Yang, Sheng" , kvm , "bonenkamp@gmx.de" , Chris Wright To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43965 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754606Ab0DWNEH (ORCPT ); Fri, 23 Apr 2010 09:04:07 -0400 In-Reply-To: <4BD17F0D.5070201@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 04/23/2010 07:05 AM, Avi Kivity wrote: > On 04/22/2010 10:55 PM, Gleb Natapov wrote: >> >> >>>> What about converting PIC/IOAPIC mutexes into spinlocks? >>>> >>> Works for me, but on large guests the spinning will be noticeable. >>> I believe. >>> >> For interrupts going through IOPIC, but we know this is not scalable >> anyway. >> > > Yes. We also wanted to convert the ioapic/pic to spinlocks so we could > queue the interrupt from the PIT directly instead of using > KVM_REQ_PENDING_TIMER which keeps confusing me. Chris Lalancette posted > a patchset for this a while back but it was never completed. Yeah, I'm sorry I never completed it. It turns out that with the HPET changes that went in around the time I was looking at it, that set of patches wasn't really required to fix the problem I was seeing with kdump. That being said, if it's useful to somebody, I can repost the patches (though they are woefully out-of-date now). Let me know if you want to see them again. -- Chris Lalancette