From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: performance counters Date: Fri, 16 Mar 2007 08:17:46 +0000 Message-ID: <45FA60BA.76E4.0078.0@novell.com> References: <45F9683D.76E4.0078.0@novell.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.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org >>> Keir Fraser 15.03.07 16:03 >>> >On 15/3/07 14:37, "Jan Beulich" wrote: > >>> at least on architectures where we know the resulting incorrectness is not >>> 'too bad' (that includes x86). Some of the shared counters are on hot paths. >>> Alternatively we could make *all* counters per-cpu, even histogram counter >>> arrays. >> >> To me that would seem like the better alternative than dropping atomicity. > >It has the added benefit of avoiding cacheline bouncing. > >It just needs someone to implement this improvement. ;-) I'll take care of this, but it may take me a few days to get to it. But I also think there's no need for rush here. Jan