From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:54398 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755400AbeEIJ7s (ORCPT ); Wed, 9 May 2018 05:59:48 -0400 Date: Wed, 9 May 2018 11:59:38 +0200 From: Peter Zijlstra To: Johannes Weiner 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: <20180509095938.GJ12217@hirez.programming.kicks-ass.net> References: <20180507210135.1823-1-hannes@cmpxchg.org> <20180507210135.1823-7-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180507210135.1823-7-hannes@cmpxchg.org> Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org 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. > +}; > + > +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. > + /* 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. > + /* Start of current non-idle state (cpu_clock) */ > + u64 nonidle_start; > + > + /* Time sampling bucket for non-idle state (ns) */ > + u64 nonidle_time; > +}; > + > +struct psi_group { > + struct psi_group_cpu *cpus; > + > + struct delayed_work clock_work; > + unsigned long period_expires; > + > + u64 some[NR_PSI_RESOURCES]; > + u64 full[NR_PSI_RESOURCES]; > + > + unsigned long avg_some[NR_PSI_RESOURCES][3]; > + unsigned long avg_full[NR_PSI_RESOURCES][3]; > +};