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[46.139.12.213]) by smtp.gmail.com with ESMTPSA id a17sm3601485wmg.40.2019.04.19.05.49.46 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 19 Apr 2019 05:49:47 -0700 (PDT) Date: Fri, 19 Apr 2019 14:49:44 +0200 From: Ingo Molnar To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , linux-kernel@vger.kernel.org, x86@kernel.org, Davidlohr Bueso , Linus Torvalds , Tim Chen , huang ying Subject: Re: [PATCH v5 00/18] locking/rwsem: Rwsem rearchitecture part 2 Message-ID: <20190419124944.GA44010@gmail.com> References: <20190418234628.3675-1-longman@redhat.com> <8f1adff7-3bd4-7d35-1a0d-698662bfa2b8@redhat.com> <20190419075055.GA6795@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190419075055.GA6795@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar wrote: > > * Waiman Long wrote: > > > On 04/18/2019 07:46 PM, Waiman Long wrote: > > > v5: > > > - Drop v4 patch 1 as it is merged into tip's locking/core branch. > > > - Integrate the 2 followup patches into the series. The first > > > follow-up patch is broken into 2 pieces. The first piece comes in > > > before the "Enable readers spinning on writer" and the 2nd piece > > > is merged into the "Enable time-based spinning on reader-owned > > > rwsem" patch. The 2nd followup patch is added after that. > > > - Add a new patch to make all wake_up_q() calls after dropping > > > wait_lock as suggested by PeterZ. > > > - Incorporate numerouos suggestions by PeterZ and Davidlohr. > > > > This patchset is still being reviewed by Peter . The purpose of this > > series is mainly to sync up the version that Peter has and the ones that > > I am working on incorporating his feedback. Further changes may still be > > needed. > > > > I run an overall performance test on this new patchset and present the > > data in this cover letter. However, I haven't run performance tests for > > individual patches. So the performance data listed in some of the > > patches may be stale. > > Just for those who'd like to follow the scope of changes, find below the > v4->v5 interdiff. v5 is now included in tip:WIP.locking/core, and also > merged into tip:master. (But not propagated towards linux-next yet.) Hm, I'm experiencing early boot hangs with v5, on defconfig-ish x86-64 kernels: [ 0.153940] rcu: Hierarchical RCU implementation. [ 0.154289] rcu: RCU restricting CPUs from NR_CPUS=128 to nr_cpu_ids=17. [ 0.154829] rcu: RCU calculated value of scheduler-enlistment delay is 100 jiffies. [ 0.155390] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=17 I bisected it back to the v5 version of this patch: 2fd5f60fa4c3: locking/rwsem: Merge owner into count on x86-64 I'm moving -tip back to -v4 meanwhile. Thanks, Ingo