From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [patch 00/11] convert slotslock to SRCU Date: Wed, 23 Dec 2009 14:37:02 +0200 Message-ID: <4B320EEE.9020506@redhat.com> References: <20091223113833.742662117@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34461 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751172AbZLWMhE (ORCPT ); Wed, 23 Dec 2009 07:37:04 -0500 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nBNCb4lN026258 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 23 Dec 2009 07:37:04 -0500 In-Reply-To: <20091223113833.742662117@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/23/2009 01:38 PM, Marcelo Tosatti wrote: > Now that synchronize_srcu_expedited is in the tree, we can continue the > convertion of slots_lock to SRCU. > > Okay, looks pretty good. The only issue I see is where to put srcu_read_lock()s: - outer scope (more reuse for archs, less places to forget) - inner scope (tighter code) There is now a mix of the two. > Results: > up: > > vmcall 6.1% improvement > > smp 2: > > > vmcall 9.3% improvement > Pretty impressive, all this from removing an uncontended semaphore. -- error compiling committee.c: too many arguments to function