From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paul Mackerras <paulus@ozlabs.org>
Date: Mon, 20 Jun 2016 05:25:13 +0000
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>
List-Id: <kvm-ppc.vger.kernel.org>
References: <1463381898.19947.6.camel@TP420>
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To: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: kvm-ppc@vger.kernel.org, PowerPC email list <linuxppc-dev@lists.ozlabs.org>, agraf@suse.com, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Michael Ellerman <mpe@ellerman.id.au>

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.