From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757324AbeEJNrn (ORCPT ); Thu, 10 May 2018 09:47:43 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:50134 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757098AbeEJNr3 (ORCPT ); Thu, 10 May 2018 09:47:29 -0400 Date: Thu, 10 May 2018 09:49:21 -0400 From: Johannes Weiner To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org, cgroups@vger.kernel.org, Ingo Molnar , Andrew Morton , Tejun Heo , Balbir Singh , Mike Galbraith , Oliver Yang , Shakeel Butt , xxx xxx , Taras Kondratiuk , Daniel Walker , Vinayak Menon , Ruslan Ruslichenko , kernel-team@fb.com Subject: Re: [PATCH 6/7] psi: pressure stall information for CPU, memory, and IO Message-ID: <20180510134921.GC19348@cmpxchg.org> References: <20180507210135.1823-1-hannes@cmpxchg.org> <20180507210135.1823-7-hannes@cmpxchg.org> <20180509095938.GJ12217@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180509095938.GJ12217@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 09, 2018 at 11:59:38AM +0200, Peter Zijlstra wrote: > On Mon, May 07, 2018 at 05:01:34PM -0400, Johannes Weiner wrote: > > diff --git a/include/linux/psi_types.h b/include/linux/psi_types.h > > new file mode 100644 > > index 000000000000..b22b0ffc729d > > --- /dev/null > > +++ b/include/linux/psi_types.h > > @@ -0,0 +1,84 @@ > > +#ifndef _LINUX_PSI_TYPES_H > > +#define _LINUX_PSI_TYPES_H > > + > > +#include > > + > > +#ifdef CONFIG_PSI > > + > > +/* Tracked task states */ > > +enum psi_task_count { > > + NR_RUNNING, > > + NR_IOWAIT, > > + NR_MEMSTALL, > > + NR_PSI_TASK_COUNTS, > > +}; > > + > > +/* Task state bitmasks */ > > +#define TSK_RUNNING (1 << NR_RUNNING) > > +#define TSK_IOWAIT (1 << NR_IOWAIT) > > +#define TSK_MEMSTALL (1 << NR_MEMSTALL) > > + > > +/* Resources that workloads could be stalled on */ > > +enum psi_res { > > + PSI_CPU, > > + PSI_MEM, > > + PSI_IO, > > + NR_PSI_RESOURCES, > > +}; > > + > > +/* Pressure states for a group of tasks */ > > +enum psi_state { > > + PSI_NONE, /* No stalled tasks */ > > + PSI_SOME, /* Stalled tasks & working tasks */ > > + PSI_FULL, /* Stalled tasks & no working tasks */ > > + NR_PSI_STATES, > > +}; > > + > > +struct psi_resource { > > + /* Current pressure state for this resource */ > > + enum psi_state state; > > + > > + /* Start of current state (cpu_clock) */ > > + u64 state_start; > > + > > + /* Time sampling buckets for pressure states (ns) */ > > + u64 times[NR_PSI_STATES - 1]; > > Fails to explain why no FULL. It's NONE that's excluded. I'll add a comment. > > +struct psi_group_cpu { > > + /* States of the tasks belonging to this group */ > > + unsigned int tasks[NR_PSI_TASK_COUNTS]; > > + > > AFAICT there's a hole here, that would fit the @nonidle member. Which > also avoids the later hole generated by it. Good spot, I'll reshuffle this accordingly. > > + /* Per-resource pressure tracking in this group */ > > + struct psi_resource res[NR_PSI_RESOURCES]; > > + > > + /* There are runnable or D-state tasks */ > > + bool nonidle; > > Mandatory complaint about using _Bool in composites goes here. int it is. Thanks