From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pavel Fedin <p.fedin@samsung.com>
Subject: RE: [PATCH v2 01/15] KVM: arm/arm64: VGIC: don't track used LRs in the
 distributor
Date: Fri, 02 Oct 2015 13:39:26 +0300
Message-ID: <00d701d0fcfe$9cba1d40$d62e57c0$@samsung.com>
References: <1436538111-4294-1-git-send-email-andre.przywara@arm.com>
 <1436538111-4294-2-git-send-email-andre.przywara@arm.com>
 <00cb01d0fcf8$6a906000$3fb12000$@samsung.com> <560E5D2F.1000401@arm.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: 'Marc Zyngier' <Marc.Zyngier@arm.com>, christoffer.dall@linaro.org,
	eric.auger@linaro.org, linux-arm-kernel@lists.infradead.org,
	kvm@vger.kernel.org
To: 'Andre Przywara' <andre.przywara@arm.com>,
	kvmarm@lists.cs.columbia.edu
Return-path: <kvm-owner@vger.kernel.org>
Received: from mailout2.w1.samsung.com ([210.118.77.12]:54306 "EHLO
	mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751535AbbJBKj3 (ORCPT <rfc822;kvm@vger.kernel.org>);
	Fri, 2 Oct 2015 06:39:29 -0400
Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244])
 by mailout2.w1.samsung.com
 (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May  5 2014))
 with ESMTP id <0NVL00LR29LR6450@mailout2.w1.samsung.com> for
 kvm@vger.kernel.org; Fri, 02 Oct 2015 11:39:27 +0100 (BST)
In-reply-to: <560E5D2F.1000401@arm.com>
Content-language: ru
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

 Hello!

> For instance how did you come up with that 16384? LPIs could actually be
> much bigger (in fact the emulation currently support up to 64k).

 Well, read "at least 16384". I actually don't remember the exact value you've put in.

> >  Since the map itself is actually used only for piggy-back optimization, it is possible to
> easily
> > get rid of it using for_each_set_bit(lr, vgic_cpu->lr_used, vgic->nr_lr) iteration instead.
> 
> Can't you use the ELRSR bitmap instead? The idea of lr_used sounds like
> a moot optimization to me.

 I'll take a look. You seem to be right, lr_used became a direct (well, inverted) copy of elrsr
after full elrsr synchronization was introduced long time ago. It's just current code relying on
lr_used everywhere.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia