Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932614AbXAaDth (ORCPT ); Tue, 30 Jan 2007 22:49:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932694AbXAaDth (ORCPT ); Tue, 30 Jan 2007 22:49:37 -0500 Received: from gateway-1237.mvista.com ([63.81.120.158]:1683 "EHLO localhost.localdomain" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932783AbXAaDtf (ORCPT ); Tue, 30 Jan 2007 22:49:35 -0500 Message-Id: <20070131033803.909323479@mvista.com> References: <20070131033710.420168478@mvista.com> User-Agent: quilt/0.46.mv-1 Date: Tue, 30 Jan 2007 19:37:13 -0800 From: Daniel Walker To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, johnstul@us.ibm.com, tglx@linutronix.de, mingo@elte.hu Subject: [PATCH 03/23] clocksource: drop clocksource-remove-the-update-callback.patch Content-Disposition: inline; filename=drop-clocksource-remove-the-update-callback.patch Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5634 Lines: 181 Drop. Signed-Off-By: Daniel Walker --- arch/i386/kernel/tsc.c | 51 +++++++++++++++++++++++++++++--------------- include/linux/clocksource.h | 11 ++++++--- kernel/timer.c | 3 ++ 3 files changed, 45 insertions(+), 20 deletions(-) Index: linux-2.6.19/arch/i386/kernel/tsc.c =================================================================== --- linux-2.6.19.orig/arch/i386/kernel/tsc.c +++ linux-2.6.19/arch/i386/kernel/tsc.c @@ -60,6 +60,12 @@ static inline int check_tsc_unstable(voi return tsc_unstable; } +void mark_tsc_unstable(void) +{ + tsc_unstable = 1; +} +EXPORT_SYMBOL_GPL(mark_tsc_unstable); + /* Accellerators for sched_clock() * convert from cycles(64bits) => nanoseconds (64bits) * basic equation: @@ -289,6 +295,7 @@ core_initcall(cpufreq_tsc); /* clock source code */ static unsigned long current_tsc_khz = 0; +static int tsc_update_callback(void); static cycle_t read_tsc(void) { @@ -306,28 +313,38 @@ static struct clocksource clocksource_ts .mask = CLOCKSOURCE_MASK(64), .mult = 0, /* to be set */ .shift = 22, + .update_callback = tsc_update_callback, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, }; -void mark_tsc_unstable(void) +static int tsc_update_callback(void) { - if (!tsc_unstable) { - tsc_unstable = 1; - /* Can be called before registration */ - if (clocksource_tsc.mult) - clocksource_change_rating(&clocksource_tsc, 0); - else - clocksource_tsc.rating = 0; + int change = 0; + + /* check to see if we should switch to the safe clocksource: */ + if (clocksource_tsc.rating != 0 && check_tsc_unstable()) { + clocksource_tsc.rating = 0; + clocksource_reselect(); + change = 1; + } + + /* only update if tsc_khz has changed: */ + if (current_tsc_khz != tsc_khz) { + current_tsc_khz = tsc_khz; + clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, + clocksource_tsc.shift); + change = 1; } + + return change; } -EXPORT_SYMBOL_GPL(mark_tsc_unstable); static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d) { printk(KERN_NOTICE "%s detected: marking TSC unstable.\n", d->ident); - tsc_unstable = 1; + mark_tsc_unstable(); return 0; } @@ -399,12 +416,11 @@ __cpuinit int unsynchronized_tsc(void) * Intel systems are normally all synchronized. * Exceptions must mark TSC as unstable: */ - if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) { - /* assume multi socket systems are not synchronized: */ - if (num_possible_cpus() > 1) - tsc_unstable = 1; - } - return tsc_unstable; + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) + return 0; + + /* assume multi socket systems are not synchronized: */ + return num_possible_cpus() > 1; } /* @@ -433,7 +449,8 @@ static int __init init_tsc_clocksource(v /* check blacklist */ dmi_check_system(bad_tsc_dmi_table); - unsynchronized_tsc(); + if (unsynchronized_tsc()) /* mark unstable if unsynced */ + mark_tsc_unstable(); check_geode_tsc_reliable(); current_tsc_khz = tsc_khz; clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, Index: linux-2.6.19/include/linux/clocksource.h =================================================================== --- linux-2.6.19.orig/include/linux/clocksource.h +++ linux-2.6.19/include/linux/clocksource.h @@ -44,6 +44,7 @@ typedef u64 cycle_t; * subtraction of non 64 bit counters * @mult: cycle to nanosecond multiplier * @shift: cycle to nanosecond divisor (power of two) + * @update_callback: called when safe to alter clocksource values * @flags: flags describing special properties * @vread: vsyscall based read * @cycle_interval: Used internally by timekeeping core, please ignore. @@ -57,6 +58,7 @@ struct clocksource { cycle_t mask; u32 mult; u32 shift; + int (*update_callback)(void); unsigned long flags; cycle_t (*vread)(void); @@ -184,9 +186,9 @@ static inline void clocksource_calculate /* used to install a new clocksource */ -extern int clocksource_register(struct clocksource*); -extern struct clocksource* clocksource_get_next(void); -extern void clocksource_change_rating(struct clocksource *cs, int rating); +int clocksource_register(struct clocksource*); +void clocksource_reselect(void); +struct clocksource* clocksource_get_next(void); #ifdef CONFIG_GENERIC_TIME_VSYSCALL extern void update_vsyscall(struct timespec *ts, struct clocksource *c); @@ -196,4 +198,7 @@ static inline void update_vsyscall(struc } #endif +#define clocksource_reselect() clocksource_change_rating(&clocksource_tsc, clocksource_tsc.rating) +extern void clocksource_change_rating(struct clocksource *cs, int rating); + #endif /* _LINUX_CLOCKSOURCE_H */ Index: linux-2.6.19/kernel/timer.c =================================================================== --- linux-2.6.19.orig/kernel/timer.c +++ linux-2.6.19/kernel/timer.c @@ -893,6 +893,8 @@ static int change_clocksource(void) printk(KERN_INFO "Time: %s clocksource has been installed.\n", clock->name); return 1; + } else if (clock->update_callback) { + return clock->update_callback(); } return 0; } @@ -959,6 +961,7 @@ void __init timekeeping_init(void) write_sequnlock_irqrestore(&xtime_lock, flags); } + /* flag for if timekeeping is suspended */ static int timekeeping_suspended; /* time in seconds when suspend began */ -- - 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/