Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932068AbVIGINO (ORCPT ); Wed, 7 Sep 2005 04:13:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932076AbVIGINO (ORCPT ); Wed, 7 Sep 2005 04:13:14 -0400 Received: from ylpvm12-ext.prodigy.net ([207.115.57.43]:60593 "EHLO ylpvm12.prodigy.net") by vger.kernel.org with ESMTP id S932068AbVIGINN (ORCPT ); Wed, 7 Sep 2005 04:13:13 -0400 X-ORBL: [67.117.73.34] Date: Wed, 7 Sep 2005 11:13:04 +0300 From: Tony Lindgren To: Nishanth Aravamudan Cc: Srivatsa Vaddagiri , Con Kolivas , linux-kernel@vger.kernel.org, akpm@osdl.org, ck list , rmk+lkml@arm.linux.org.uk Subject: Re: [PATCH 1/3] dynticks - implement no idle hz for x86 Message-ID: <20050907081303.GC5804@atomide.com> References: <200509031801.09069.kernel@kolivas.org> <20050903090650.B26998@flint.arm.linux.org.uk> <200509031814.49666.kernel@kolivas.org> <20050904201054.GA4495@us.ibm.com> <20050904212616.B11265@flint.arm.linux.org.uk> <20050905053225.GA4294@in.ibm.com> <20050905054813.GC25856@us.ibm.com> <20050905063229.GB4294@in.ibm.com> <20050905064416.GD25856@us.ibm.com> <20050906205112.GA3038@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050906205112.GA3038@us.ibm.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2243 Lines: 63 * Nishanth Aravamudan [050906 23:55]: ... > Sigh, later than I had hoped, but here is what I have hashed out so far. > Does it seem like a step in the right direction? Rather hand-wavy, but I > think it's mostly correct ;) Some comments below. > - include/linux/intsource.h > with definitions in kernel/intsource.c > > #define DYN_TICK_ENABLED (1 << 1) > #define DYN_TICK_SUITABLE (1 << 0) > > #define DYN_TICK_MIN_SKIP 2 > > /* Abstraction of an interrupt source > * @state: current state > * @max_skip: current maximum number of ticks to skip > * @arch_init: initialization routine > * @arch_enable_dyn_tick: called via sysfs to enable interrupt skipping > * @arch_disable_dyn_tick: called via sysfs to disable interrupt > * skipping > * @arch_set_all_cpus_idle: last cpu to go idle calls this, which should > * disable any timesource (e.g. PIT on x86) > * @arch_recover_time: handler for returning from skipped ticks and keeping > * time consistent > */ > struct interrupt_source { > unsigned int state; > unsigned long max_skip; > int (*arch_init) (void); > void (*arch_enable_dyn_tick) (void); > void (*arch_disable_dyn_tick) (void); > unsigned long (*arch_reprogram) (unsigned long); /* return number of ticks skipped */ > unsigned long (*arch_recover_time) (int, void *, struct pt_regs *); /* handler in arm */ > /* following empty in UP */ > void (*arch_set_all_cpus_idle) (int); > spinlock_t lock; > }; I would still call the struct dyntick, have CONFIG_DYNTICK, and then have CONFIG_NO_IDLE_HZ and possibly CONFIG_SUBJIFFIE_TIMER register to use it like I said in my earlier mail. Would that solve the issues you have with the naming? > /* return number of ticks skipped, potentially for accounting purposes? */ > extern unsigned long reprogram_interrupt(void); The number of ticks skipped can be potentially used in idle loops to select which ACPI C state to go to depending on the estimated length of sleep. Regards, Tony - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/