From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53915) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xuizu-0007rx-8O for qemu-devel@nongnu.org; Sat, 29 Nov 2014 09:27:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xuizj-000748-6l for qemu-devel@nongnu.org; Sat, 29 Nov 2014 09:27:42 -0500 Received: from mail-wi0-x229.google.com ([2a00:1450:400c:c05::229]:62317) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xuizi-00073x-W3 for qemu-devel@nongnu.org; Sat, 29 Nov 2014 09:27:31 -0500 Received: by mail-wi0-f169.google.com with SMTP id r20so22878090wiv.4 for ; Sat, 29 Nov 2014 06:27:30 -0800 (PST) Sender: Paolo Bonzini Message-ID: <5479D7CE.8060200@redhat.com> Date: Sat, 29 Nov 2014 15:27:26 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1417183941-26329-1-git-send-email-pbonzini@redhat.com> <1417183941-26329-8-git-send-email-pbonzini@redhat.com> <5478E0A5.6060405@kamp.de> In-Reply-To: <5478E0A5.6060405@kamp.de> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 7/7] coroutine: try harder not to delete coroutines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven , qemu-devel@nongnu.org Cc: kwolf@redhat.com, ming.lei@canonical.com, stefanha@redhat.com On 28/11/2014 21:52, Peter Lieven wrote: > > master: > Run operation 40000000 iterations 13.612604 s, 2938K operations/s, 340ns per coroutine > > this series up to patch 6: > Run operation 40000000 iterations 10.428382 s, 3835K operations/s, 260ns per coroutine > > this series up to patch 7: > Run operation 40000000 iterations 9.112539 s, 4389K operations/s, 227ns per coroutine > > So this confirms the +33% Paolo sees up to Patch 5. But I have yet fully understood the > +15% that this Patch gains. No atomic operations once the release pool gets full. We're talking of 800 clock cycles here, and one atomic operation costs 50 cycles. 100 clock cycles out of 800 = 15% speedup (8/7 = 1.14). Paolo