From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [v3 12/15] vmx: posted-interrupt handling when vCPU is blocked Date: Wed, 08 Jul 2015 11:48:04 +0100 Message-ID: <559D1C04020000780008E1BC@mail.emea.novell.com> References: <1435123109-10481-1-git-send-email-feng.wu@intel.com> <1435123109-10481-13-git-send-email-feng.wu@intel.com> <55917B35.2070706@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Feng Wu Cc: Kevin Tian , "keir@xen.org" , "george.dunlap@eu.citrix.com" , Andrew Cooper , "xen-devel@lists.xen.org" , Yang Z Zhang List-Id: xen-devel@lists.xenproject.org >>> On 08.07.15 at 12:36, wrote: >> From: Andrew Cooper [mailto:andrew.cooper3@citrix.com] >> Sent: Tuesday, June 30, 2015 1:07 AM >> On 24/06/15 06:18, Feng Wu wrote: >> > @@ -148,11 +161,19 @@ static int vmx_vcpu_initialise(struct vcpu *v) >> > if ( v->vcpu_id == 0 ) >> > v->arch.user_regs.eax = 1; >> > >> > + tasklet_init( >> > + &v->arch.hvm_vmx.pi_vcpu_wakeup_tasklet, >> > + pi_vcpu_wakeup_tasklet_handler, >> > + (unsigned long)v); >> >> c/s f6dd295 indicates that the global tasklet lock causes a bottleneck >> when injecting interrupts, and replaced a tasklet with a softirq to fix >> the scalability issue. >> >> I would expect exactly the bottleneck to exist here. > > I am still considering this comments. Jan, what is your opinion about this? "My opinion" here is that I expect you to respond to Andrew. Jan