From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH v3 0/6] powerpc: queued spinlocks and rwlocks Date: Thu, 9 Jul 2020 10:31:13 +0200 Message-ID: <20200709083113.GI597537@hirez.programming.kicks-ass.net> References: <20200706043540.1563616-1-npiggin@gmail.com> <24f75d2c-60cd-2766-4aab-1a3b1c80646e@redhat.com> <1594101082.hfq9x5yact.astroid@bobo.none> <20200708084106.GE597537@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Waiman Long Cc: linux-arch@vger.kernel.org, Will Deacon , Boqun Feng , linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, virtualization@lists.linux-foundation.org, Ingo Molnar , Nicholas Piggin , Anton Blanchard , linuxppc-dev@lists.ozlabs.org List-Id: virtualization@lists.linuxfoundation.org On Wed, Jul 08, 2020 at 07:54:34PM -0400, Waiman Long wrote: > On 7/8/20 4:41 AM, Peter Zijlstra wrote: > > On Tue, Jul 07, 2020 at 03:57:06PM +1000, Nicholas Piggin wrote: > > > Yes, powerpc could certainly get more performance out of the slow > > > paths, and then there are a few parameters to tune. > > Can you clarify? The slow path is already in use on ARM64 which is weak, > > so I doubt there's superfluous serialization present. And Will spend a > > fair amount of time on making that thing guarantee forward progressm, so > > there just isn't too much room to play. > > > > > We don't have a good alternate patching for function calls yet, but > > > that would be something to do for native vs pv. > > Going by your jump_label implementation, support for static_call should > > be fairly straight forward too, no? > > > > https://lkml.kernel.org/r/20200624153024.794671356@infradead.org > > > Speaking of static_call, I am also looking forward to it. Do you have an > idea when that will be merged? 0day had one crash on the last round, I think Steve send a fix for that last night and I'll go look at it. That said, the last posting got 0 feedback, so either everybody is really happy with it, or not interested. So let us know in the thread, with some review feedback. Once I get through enough of the inbox to actually find the fix and test it, I'll also update the thread, and maybe threaten to merge it if everybody stays silent :-)