From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rpBP46mTzzDqpR for ; Tue, 12 Jul 2016 03:07:52 +1000 (AEST) Subject: Re: [PATCH V2 3/5] kvm/ppc/book3s_hv: Implement halt polling in the kvm_hv kernel module To: David Matlack , Suraj Jitindar Singh References: <1468220912-22828-1-git-send-email-sjitindarsingh@gmail.com> <1468220912-22828-3-git-send-email-sjitindarsingh@gmail.com> Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, mpe@ellerman.id.au, paulus@samba.org, benh@kernel.crashing.org, kvm list , agraf@suse.com, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= From: Paolo Bonzini Message-ID: <78e920ba-b596-5475-ff30-0dd2c23d97b6@redhat.com> Date: Mon, 11 Jul 2016 19:07:45 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 11/07/2016 18:57, David Matlack wrote: > On Mon, Jul 11, 2016 at 12:08 AM, Suraj Jitindar Singh > wrote: > > This patch introduces new halt polling functionality into the kvm_hv kernel > > module. When a vcore is idle it will poll for some period of time before > > scheduling itself out. > > Is there any way to reuse the existing halt-polling code? Having two > copies risks them diverging over time. s/risks/guarantees/ :( Unfortunately, handling of the hardware threads in KVM PPC is a mess, and I don't think it's possible to remove the duplication. Paolo