From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rXzrV1PN1zDqCX for ; Mon, 20 Jun 2016 15:27:22 +1000 (AEST) Date: Mon, 20 Jun 2016 15:25:13 +1000 From: Paul Mackerras To: Li Zhong Cc: kvm-ppc@vger.kernel.org, PowerPC email list , agraf@suse.com, Benjamin Herrenschmidt , Michael Ellerman Subject: Re: [RFC PATCH 1/2] KVM: PPC: divide the ics lock into smaller ones for each irq Message-ID: <20160620052513.GB29366@fergus.ozlabs.ibm.com> References: <1463381898.19947.6.camel@TP420> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1463381898.19947.6.camel@TP420> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, May 16, 2016 at 02:58:18PM +0800, Li Zhong wrote: > This patch tries to use smaller locks for each irq in the ics, instead > of a lock at the ics level, to provide better scalability. This looks like a worth-while thing to do. Do you have any performance measurements to justify the change? This will increase the size of struct kvmppc_ics by 4kB, so it would be useful to show the performance increase that justifies it. Also, when you resend the patch, please make the patch description more definite - say "With this patch, we use" rather than "this patch tries to use", for instance. Regards, Paul.