From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x241.google.com (mail-pg0-x241.google.com [IPv6:2607:f8b0:400e:c05::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3w1b9L4dD2zDq7h for ; Mon, 10 Apr 2017 13:23:02 +1000 (AEST) Received: by mail-pg0-x241.google.com with SMTP id 81so23999753pgh.3 for ; Sun, 09 Apr 2017 20:23:02 -0700 (PDT) Date: Mon, 10 Apr 2017 13:22:45 +1000 From: Nicholas Piggin To: Benjamin Herrenschmidt Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras Subject: Re: [PATCH 1/5] powerpc/pseries: do not use msgsndp doorbells on POWER9 guests Message-ID: <20170410132245.16802599@roar.ozlabs.ibm.com> In-Reply-To: <1491725015.4166.188.camel@kernel.crashing.org> References: <20170407125602.31146-1-npiggin@gmail.com> <20170407125602.31146-2-npiggin@gmail.com> <1491725015.4166.188.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sun, 09 Apr 2017 18:03:35 +1000 Benjamin Herrenschmidt wrote: > On Fri, 2017-04-07 at 22:55 +1000, Nicholas Piggin wrote: > > POWER9 hypervisors will not necessarily run guest threads together on > > the same core at the same time, so msgsndp should not be used. > > Maybe we shouldn't advertise doorbells at all ? Possibly not. I don't know if there is a good way to switch it off in the guest from the host with device tree currently. Might be better to clear it early in the guest rather than test it here though? Thanks, Nick