From 6ce51c431019310ca03371355a4366c4649fa349 Mon Sep 17 00:00:00 2001 From: Luis Henriques Date: Wed, 1 Apr 2009 18:06:35 +0100 Subject: genirq: do not execute DEBUG_SHIRQ when irq setup failed When requesting an IRQ, the DEBUG_SHIRQ code executes a fake IRQ just to make sure the driver is ready to receive an IRQ immediately. The problem was that this fake IRQ was being executed even if interrupt line failed to be allocated by __setup_irq. Signed-off-by: Luis Henriques LKML-Reference: <20090401170635.GA4392@hades.domain.com> Signed-off-by: Thomas Gleixner [ fixed bug pointed out by a warning reported by Stephen Rothwell ] Cc: Stephen Rothwell Signed-off-by: Ingo Molnar --- kernel/irq/manage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 1516ab77355c..8c68d5b95d48 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -768,7 +768,7 @@ int request_irq(unsigned int irq, irq_handler_t handler, kfree(action); #ifdef CONFIG_DEBUG_SHIRQ - if (irqflags & IRQF_SHARED) { + if (!retval && (irqflags & IRQF_SHARED)) { /* * It's a shared IRQ -- the driver ought to be prepared for it * to happen immediately, so let's make sure.... -- cgit v1.2.3 From a092ff0f90cae22b2ac8028ecd2c6f6c1a9e4601 Mon Sep 17 00:00:00 2001 From: john stultz Date: Fri, 2 Oct 2009 16:17:53 -0700 Subject: time: Implement logarithmic time accumulation Accumulating one tick at a time works well unless we're using NOHZ. Then it can be an issue, since we may have to run through the loop a few thousand times, which can increase timer interrupt caused latency. The current solution was to accumulate in half-second intervals with NOHZ. This kept the number of loops down, however it did slightly change how we make NTP adjustments. While not an issue with NTPd users, as NTPd makes adjustments over a longer period of time, other adjtimex() users have noticed the half-second granularity with which we can apply frequency changes to the clock. For instance, if a application tries to apply a 100ppm frequency correction for 20ms to correct a 2us offset, with NOHZ they either get no correction, or a 50us correction. Now, there will always be some granularity error for applying frequency corrections. However with users sensitive to this error have seen a 50-500x increase with NOHZ compared to running without NOHZ. So I figured I'd try another approach then just simply increasing the interval. My approach is to consume the time interval logarithmically. This reduces the number of times through the loop needed keeping latency down, while still preserving the original granularity error for adjtimex() changes. Further, this change allows us to remove the xtime_cache code (patch to follow), as xtime is always within one tick of the current time, instead of the half-second updates it saw before. An earlier version of this patch has been shipping to x86 users in the RedHat MRG releases for awhile without issue, but I've reworked this version to be even more careful about avoiding possible overflows if the shift value gets too large. Signed-off-by: John Stultz Acked-by: Thomas Gleixner Reviewed-by: John Kacur Cc: Clark Williams Cc: Martin Schwidefsky Cc: Andrew Morton LKML-Reference: <1254525473.7741.88.camel@localhost.localdomain> Signed-off-by: Ingo Molnar --- kernel/time/timekeeping.c | 85 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 60 insertions(+), 25 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index fb0f46fa1ecd..5fdd78e0858a 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -721,6 +721,51 @@ static void timekeeping_adjust(s64 offset) timekeeper.ntp_error_shift; } + +/** + * logarithmic_accumulation - shifted accumulation of cycles + * + * This functions accumulates a shifted interval of cycles into + * into a shifted interval nanoseconds. Allows for O(log) accumulation + * loop. + * + * Returns the unconsumed cycles. + */ +static cycle_t logarithmic_accumulation(cycle_t offset, int shift) +{ + u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; + + /* If the offset is smaller then a shifted interval, do nothing */ + if (offset < timekeeper.cycle_interval<cycle_last += timekeeper.cycle_interval << shift; + + timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; + while (timekeeper.xtime_nsec >= nsecps) { + timekeeper.xtime_nsec -= nsecps; + xtime.tv_sec++; + second_overflow(); + } + + /* Accumulate into raw time */ + raw_time.tv_nsec += timekeeper.raw_interval << shift;; + while (raw_time.tv_nsec >= NSEC_PER_SEC) { + raw_time.tv_nsec -= NSEC_PER_SEC; + raw_time.tv_sec++; + } + + /* Accumulate error between NTP and clock interval */ + timekeeper.ntp_error += tick_length << shift; + timekeeper.ntp_error -= timekeeper.xtime_interval << + (timekeeper.ntp_error_shift + shift); + + return offset; +} + + /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -731,6 +776,7 @@ void update_wall_time(void) struct clocksource *clock; cycle_t offset; u64 nsecs; + int shift = 0, maxshift; /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) @@ -744,33 +790,22 @@ void update_wall_time(void) #endif timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; - /* normally this loop will run just once, however in the - * case of lost or late ticks, it will accumulate correctly. + /* + * With NO_HZ we may have to accumulate many cycle_intervals + * (think "ticks") worth of time at once. To do this efficiently, + * we calculate the largest doubling multiple of cycle_intervals + * that is smaller then the offset. We then accumulate that + * chunk in one go, and then try to consume the next smaller + * doubled multiple. */ + shift = ilog2(offset) - ilog2(timekeeper.cycle_interval); + shift = max(0, shift); + /* Bound shift to one less then what overflows tick_length */ + maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1; + shift = min(shift, maxshift); while (offset >= timekeeper.cycle_interval) { - u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; - - /* accumulate one interval */ - offset -= timekeeper.cycle_interval; - clock->cycle_last += timekeeper.cycle_interval; - - timekeeper.xtime_nsec += timekeeper.xtime_interval; - if (timekeeper.xtime_nsec >= nsecps) { - timekeeper.xtime_nsec -= nsecps; - xtime.tv_sec++; - second_overflow(); - } - - raw_time.tv_nsec += timekeeper.raw_interval; - if (raw_time.tv_nsec >= NSEC_PER_SEC) { - raw_time.tv_nsec -= NSEC_PER_SEC; - raw_time.tv_sec++; - } - - /* accumulate error between NTP and clock interval */ - timekeeper.ntp_error += tick_length; - timekeeper.ntp_error -= timekeeper.xtime_interval << - timekeeper.ntp_error_shift; + offset = logarithmic_accumulation(offset, shift); + shift--; } /* correct the clock when NTP error is too big */ -- cgit v1.2.3 From 7bc7d637452383d56ba4368d4336b0dde1bb476d Mon Sep 17 00:00:00 2001 From: john stultz Date: Fri, 2 Oct 2009 16:24:15 -0700 Subject: time: Remove xtime_cache With the prior logarithmic time accumulation patch, xtime will now always be within one "tick" of the current time, instead of possibly half a second off. This removes the need for the xtime_cache value, which always stored the time at the last interrupt, so this patch cleans that up removing the xtime_cache related code. This is a bit simpler, but still could use some wider testing. Signed-off-by: John Stultz Acked-by: Thomas Gleixner Reviewed-by: John Kacur Cc: Clark Williams Cc: Martin Schwidefsky Cc: Andrew Morton LKML-Reference: <1254525855.7741.95.camel@localhost.localdomain> Signed-off-by: Ingo Molnar --- kernel/time.c | 1 - kernel/time/timekeeping.c | 27 ++++----------------------- 2 files changed, 4 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/time.c b/kernel/time.c index 2e2e469a7fec..2ef4fe2079b6 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -136,7 +136,6 @@ static inline void warp_clock(void) write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; - update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set(); } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 5fdd78e0858a..96b3f0dfa5dc 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -164,13 +164,6 @@ struct timespec raw_time; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; -static struct timespec xtime_cache __attribute__ ((aligned (16))); -void update_xtime_cache(u64 nsec) -{ - xtime_cache = xtime; - timespec_add_ns(&xtime_cache, nsec); -} - /* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { @@ -331,8 +324,6 @@ int do_settimeofday(struct timespec *tv) xtime = *tv; - update_xtime_cache(0); - timekeeper.ntp_error = 0; ntp_clear(); @@ -547,7 +538,6 @@ void __init timekeeping_init(void) } set_normalized_timespec(&wall_to_monotonic, -boot.tv_sec, -boot.tv_nsec); - update_xtime_cache(0); total_sleep_time.tv_sec = 0; total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -581,7 +571,6 @@ static int timekeeping_resume(struct sys_device *dev) wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); total_sleep_time = timespec_add_safe(total_sleep_time, ts); } - update_xtime_cache(0); /* re-base the last cycle value */ timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); timekeeper.ntp_error = 0; @@ -721,7 +710,6 @@ static void timekeeping_adjust(s64 offset) timekeeper.ntp_error_shift; } - /** * logarithmic_accumulation - shifted accumulation of cycles * @@ -765,7 +753,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) return offset; } - /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -775,7 +762,6 @@ void update_wall_time(void) { struct clocksource *clock; cycle_t offset; - u64 nsecs; int shift = 0, maxshift; /* Make sure we're fully resumed: */ @@ -841,9 +827,6 @@ void update_wall_time(void) timekeeper.ntp_error += timekeeper.xtime_nsec << timekeeper.ntp_error_shift; - nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift); - update_xtime_cache(nsecs); - /* check to see if there is a new clocksource to use */ update_vsyscall(&xtime, timekeeper.clock); } @@ -880,13 +863,13 @@ void monotonic_to_bootbased(struct timespec *ts) unsigned long get_seconds(void) { - return xtime_cache.tv_sec; + return xtime.tv_sec; } EXPORT_SYMBOL(get_seconds); struct timespec __current_kernel_time(void) { - return xtime_cache; + return xtime; } struct timespec current_kernel_time(void) @@ -896,8 +879,7 @@ struct timespec current_kernel_time(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; } while (read_seqretry(&xtime_lock, seq)); return now; @@ -911,8 +893,7 @@ struct timespec get_monotonic_coarse(void) do { seq = read_seqbegin(&xtime_lock); - - now = xtime_cache; + now = xtime; mono = wall_to_monotonic; } while (read_seqretry(&xtime_lock, seq)); -- cgit v1.2.3 From e6fe07a014c7a3466dcd1a387a9ac04d84c2703c Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Thu, 6 Aug 2009 13:22:40 -0600 Subject: pm_qos: remove BKL pm_qos_power_open got its lock_kernel() calls from the open() pushdown. A look at the code shows that the only global resources accessed are pm_qos_array and "name". pm_qos_array doesn't change (things pointed to therein do change, but they are atomics and/or are protected by pm_qos_lock). Accesses to "name" are totally unprotected with or without the BKL; that will be fixed shortly. The BKL is not helpful here; take it out. Signed-off-by: Jonathan Corbet LKML-Reference: <20091010153349.071381158@linutronix.de> Acked-by: Mark Gross Reviewed-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner --- kernel/pm_qos_params.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index dfdec524d1b7..d96b83ed21cb 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -29,7 +29,6 @@ #include #include -#include #include #include #include @@ -352,20 +351,15 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) int ret; long pm_qos_class; - lock_kernel(); pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { filp->private_data = (void *)pm_qos_class; sprintf(name, "process_%d", current->pid); ret = pm_qos_add_requirement(pm_qos_class, name, PM_QOS_DEFAULT_VALUE); - if (ret >= 0) { - unlock_kernel(); + if (ret >= 0) return 0; - } } - unlock_kernel(); - return -EPERM; } -- cgit v1.2.3 From 1a6deaea3584fd7af1cad492b1fe0867060b45db Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Thu, 6 Aug 2009 13:35:44 -0600 Subject: pm_qos: clean up racy global "name" variable "name" is a poor name for a file-global variable. It was used in three different functions, with no mutual exclusion. But it's just a tiny, temporary string; let's just move it onto the stack in the functions that need it. Also use snprintf() just in case. Signed-off-by: Jonathan Corbet LKML-Reference: <20091010153349.113570550@linutronix.de> Acked-by: Mark Gross Reviewed-by: Frederic Weisbecker Signed-off-by: Thomas Gleixner --- kernel/pm_qos_params.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index d96b83ed21cb..3db49b9ca374 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -343,18 +343,18 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) } EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); -#define PID_NAME_LEN sizeof("process_1234567890") -static char name[PID_NAME_LEN]; +#define PID_NAME_LEN 32 static int pm_qos_power_open(struct inode *inode, struct file *filp) { int ret; long pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { filp->private_data = (void *)pm_qos_class; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); ret = pm_qos_add_requirement(pm_qos_class, name, PM_QOS_DEFAULT_VALUE); if (ret >= 0) @@ -366,9 +366,10 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) static int pm_qos_power_release(struct inode *inode, struct file *filp) { int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_remove_requirement(pm_qos_class, name); return 0; @@ -379,13 +380,14 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, { s32 value; int pm_qos_class; + char name[PID_NAME_LEN]; pm_qos_class = (long)filp->private_data; if (count != sizeof(s32)) return -EINVAL; if (copy_from_user(&value, buf, sizeof(s32))) return -EFAULT; - sprintf(name, "process_%d", current->pid); + snprintf(name, PID_NAME_LEN, "process_%d", current->pid); pm_qos_update_requirement(pm_qos_class, name, value); return sizeof(s32); -- cgit v1.2.3 From 6f15fa50087c8317e353145319466afbeb27a75d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 9 Oct 2009 20:31:33 +0200 Subject: sys: Remove BKL from sys_reboot Serialization of sys_reboot can be done local. The BKL is not protecting anything else. LKML-Reference: <20091010153349.405590702@linutronix.de> Signed-off-by: Thomas Gleixner --- kernel/sys.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/sys.c b/kernel/sys.c index 255475d163e0..22ea9553c3bc 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -8,7 +8,6 @@ #include #include #include -#include #include #include #include @@ -349,6 +348,9 @@ void kernel_power_off(void) machine_power_off(); } EXPORT_SYMBOL_GPL(kernel_power_off); + +static DEFINE_MUTEX(reboot_mutex); + /* * Reboot system call: for obvious reasons only root may call it, * and even root needs to set up some magic numbers in the registers @@ -381,7 +383,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) cmd = LINUX_REBOOT_CMD_HALT; - lock_kernel(); + mutex_lock(&reboot_mutex); switch (cmd) { case LINUX_REBOOT_CMD_RESTART: kernel_restart(NULL); @@ -397,20 +399,18 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, case LINUX_REBOOT_CMD_HALT: kernel_halt(); - unlock_kernel(); do_exit(0); panic("cannot halt"); case LINUX_REBOOT_CMD_POWER_OFF: kernel_power_off(); - unlock_kernel(); do_exit(0); break; case LINUX_REBOOT_CMD_RESTART2: if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { - unlock_kernel(); - return -EFAULT; + ret = -EFAULT; + break; } buffer[sizeof(buffer) - 1] = '\0'; @@ -433,7 +433,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, ret = -EINVAL; break; } - unlock_kernel(); + mutex_unlock(&reboot_mutex); return ret; } -- cgit v1.2.3 From eed3b9cf3fe3fcc7a50238dfcab63a63914e8f42 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 29 Sep 2009 14:25:15 +0200 Subject: nohz: Reuse ktime in sub-functions of tick_check_idle. On a system with NOHZ=y tick_check_idle calls tick_nohz_stop_idle and tick_nohz_update_jiffies. Given the right conditions (ts->idle_active and/or ts->tick_stopped) both function get a time stamp with ktime_get. The same time stamp can be reused if both function require one. On s390 this change has the additional benefit that gcc inlines the tick_nohz_stop_idle function into tick_check_idle. The number of instructions to execute tick_check_idle drops from 225 to 144 (without the ktime_get optimization it is 367 vs 215 instructions). before: 0) | tick_check_idle() { 0) | tick_nohz_stop_idle() { 0) | ktime_get() { 0) | read_tod_clock() { 0) 0.601 us | } 0) 1.765 us | } 0) 3.047 us | } 0) | ktime_get() { 0) | read_tod_clock() { 0) 0.570 us | } 0) 1.727 us | } 0) | tick_do_update_jiffies64() { 0) 0.609 us | } 0) 8.055 us | } after: 0) | tick_check_idle() { 0) | ktime_get() { 0) | read_tod_clock() { 0) 0.617 us | } 0) 1.773 us | } 0) | tick_do_update_jiffies64() { 0) 0.593 us | } 0) 4.477 us | } Signed-off-by: Martin Schwidefsky Cc: john stultz LKML-Reference: <20090929122533.206589318@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.c | 62 ++++++++++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index e0f59a21c061..7378e2c71ca6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -134,18 +134,13 @@ __setup("nohz=", setup_tick_nohz); * value. We do this unconditionally on any cpu, as we don't know whether the * cpu, which has the update task assigned is in a long sleep. */ -static void tick_nohz_update_jiffies(void) +static void tick_nohz_update_jiffies(ktime_t now) { int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); unsigned long flags; - ktime_t now; - - if (!ts->tick_stopped) - return; cpumask_clear_cpu(cpu, nohz_cpu_mask); - now = ktime_get(); ts->idle_waketime = now; local_irq_save(flags); @@ -155,20 +150,17 @@ static void tick_nohz_update_jiffies(void) touch_softlockup_watchdog(); } -static void tick_nohz_stop_idle(int cpu) +static void tick_nohz_stop_idle(int cpu, ktime_t now) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t delta; - if (ts->idle_active) { - ktime_t now, delta; - now = ktime_get(); - delta = ktime_sub(now, ts->idle_entrytime); - ts->idle_lastupdate = now; - ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); - ts->idle_active = 0; + delta = ktime_sub(now, ts->idle_entrytime); + ts->idle_lastupdate = now; + ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + ts->idle_active = 0; - sched_clock_idle_wakeup_event(0); - } + sched_clock_idle_wakeup_event(0); } static ktime_t tick_nohz_start_idle(struct tick_sched *ts) @@ -431,7 +423,11 @@ void tick_nohz_restart_sched_tick(void) ktime_t now; local_irq_disable(); - tick_nohz_stop_idle(cpu); + if (ts->idle_active || (ts->inidle && ts->tick_stopped)) + now = ktime_get(); + + if (ts->idle_active) + tick_nohz_stop_idle(cpu, now); if (!ts->inidle || !ts->tick_stopped) { ts->inidle = 0; @@ -445,7 +441,6 @@ void tick_nohz_restart_sched_tick(void) /* Update jiffies first */ select_nohz_load_balancer(0); - now = ktime_get(); tick_do_update_jiffies64(now); cpumask_clear_cpu(cpu, nohz_cpu_mask); @@ -579,22 +574,18 @@ static void tick_nohz_switch_to_nohz(void) * timer and do not touch the other magic bits which need to be done * when idle is left. */ -static void tick_nohz_kick_tick(int cpu) +static void tick_nohz_kick_tick(int cpu, ktime_t now) { #if 0 /* Switch back to 2.6.27 behaviour */ struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); - ktime_t delta, now; - - if (!ts->tick_stopped) - return; + ktime_t delta; /* * Do not touch the tick device, when the next expiry is either * already reached or less/equal than the tick period. */ - now = ktime_get(); delta = ktime_sub(hrtimer_get_expires(&ts->sched_timer), now); if (delta.tv64 <= tick_period.tv64) return; @@ -603,9 +594,26 @@ static void tick_nohz_kick_tick(int cpu) #endif } +static inline void tick_check_nohz(int cpu) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t now; + + if (!ts->idle_active && !ts->tick_stopped) + return; + now = ktime_get(); + if (ts->idle_active) + tick_nohz_stop_idle(cpu, now); + if (ts->tick_stopped) { + tick_nohz_update_jiffies(now); + tick_nohz_kick_tick(cpu, now); + } +} + #else static inline void tick_nohz_switch_to_nohz(void) { } +static inline void tick_check_nohz(int cpu) { } #endif /* NO_HZ */ @@ -615,11 +623,7 @@ static inline void tick_nohz_switch_to_nohz(void) { } void tick_check_idle(int cpu) { tick_check_oneshot_broadcast(cpu); -#ifdef CONFIG_NO_HZ - tick_nohz_stop_idle(cpu); - tick_nohz_update_jiffies(); - tick_nohz_kick_tick(cpu); -#endif + tick_check_nohz(cpu); } /* -- cgit v1.2.3 From 3c5d92a0cfb5103c0d5ab74d4ae6373d3af38148 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 29 Sep 2009 14:25:16 +0200 Subject: nohz: Introduce arch_needs_cpu Allow the architecture to request a normal jiffy tick when the system goes idle and tick_nohz_stop_sched_tick is called . On s390 the hook is used to prevent the system going fully idle if there has been an interrupt other than a clock comparator interrupt since the last wakeup. On s390 the HiperSockets response time for 1 connection ping-pong goes down from 42 to 34 microseconds. The CPU cost decreases by 27%. Signed-off-by: Martin Schwidefsky LKML-Reference: <20090929122533.402715150@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/tick-sched.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7378e2c71ca6..3840f6dff7eb 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -264,12 +264,15 @@ void tick_nohz_stop_sched_tick(int inidle) last_jiffies = jiffies; } while (read_seqretry(&xtime_lock, seq)); - /* Get the next timer wheel timer */ - next_jiffies = get_next_timer_interrupt(last_jiffies); - delta_jiffies = next_jiffies - last_jiffies; - - if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu)) + if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) || + arch_needs_cpu(cpu)) { + next_jiffies = last_jiffies + 1; delta_jiffies = 1; + } else { + /* Get the next timer wheel timer */ + next_jiffies = get_next_timer_interrupt(last_jiffies); + delta_jiffies = next_jiffies - last_jiffies; + } /* * Do not stop the tick, if we are only one off * or if the cpu is required for rcu -- cgit v1.2.3 From b71a8eb0fa64ec6d00175f479e3ef851703568af Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Tue, 6 Oct 2009 12:42:51 +0200 Subject: tree-wide: fix typos "selct" + "slect" -> "select" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch was generated by git grep -E -i -l 's(le|el)ct' | xargs -r perl -p -i -e 's/([Ss])(le|el)ct/$1elect/ with only skipping net/netfilter/xt_SECMARK.c and include/linux/netfilter/xt_SECMARK.h which have a struct member called selctx. Signed-off-by: Uwe Kleine-König Signed-off-by: Jiri Kosina --- kernel/time/clocksource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 5e18c6ab2c6a..c403567f78c0 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -580,7 +580,7 @@ sysfs_show_current_clocksources(struct sys_device *dev, * @count: length of buffer * * Takes input from sysfs interface for manually overriding the default - * clocksource selction. + * clocksource selection. */ static ssize_t sysfs_override_clocksource(struct sys_device *dev, struct sysdev_attribute *attr, -- cgit v1.2.3 From 23af368e9a904f59256c27d371ce223d6cee0430 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 11 Nov 2009 14:05:25 +0000 Subject: clockevents: Use u32 for mult and shift factors The mult and shift factors of clock events differ in their data type from those of clock sources for no reason. u32 is sufficient for both. shift is always <= 32 and mult is limited to 2^32-1 to avoid 64bit multiplication overflows in the conversion. Preparatory patch for a generic mult/shift factor calculation function. Signed-off-by: Thomas Gleixner Tested-by: Mikael Pettersson Acked-by: Ralf Baechle Acked-by: Linus Walleij Cc: John Stultz LKML-Reference: <20091111134229.725664788@linutronix.de> --- kernel/time/timer_list.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index 1b5b7aa2fdfd..fa00da108a14 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -206,8 +206,8 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) SEQ_printf(m, "%s\n", dev->name); SEQ_printf(m, " max_delta_ns: %lu\n", dev->max_delta_ns); SEQ_printf(m, " min_delta_ns: %lu\n", dev->min_delta_ns); - SEQ_printf(m, " mult: %lu\n", dev->mult); - SEQ_printf(m, " shift: %d\n", dev->shift); + SEQ_printf(m, " mult: %u\n", dev->mult); + SEQ_printf(m, " shift: %u\n", dev->shift); SEQ_printf(m, " mode: %d\n", dev->mode); SEQ_printf(m, " next_event: %Ld nsecs\n", (unsigned long long) ktime_to_ns(dev->next_event)); -- cgit v1.2.3 From 7d2f944a2b836c69a9d260a0a5f0d1720d57fdff Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 11 Nov 2009 14:05:29 +0000 Subject: clocksource: Provide a generic mult/shift factor calculation MIPS has two functions to calculcate the mult/shift factors for clock sources and clock events at run time. ARM needs such functions as well. Implement a function which calculates the mult/shift factors based on the frequencies to which and from which is converted. The function also has a parameter to specify the minimum conversion range in seconds. This range is guaranteed not to produce a 64bit overflow when a value is multiplied with the calculated mult factor. The larger the conversion range the less becomes the conversion accuracy. Provide two inline wrappers which handle clock events and clock sources. For clock events the "from" frequency is nano seconds per second which corresponds to 1GHz and "to" is the device frequency. For clock sources "from" is the device frequency and "to" is nano seconds per second. Signed-off-by: Thomas Gleixner Tested-by: Mikael Pettersson Acked-by: Ralf Baechle Acked-by: Linus Walleij Cc: John Stultz LKML-Reference: <20091111134229.766673305@linutronix.de> --- kernel/time/clocksource.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 5e18c6ab2c6a..407c0894ef37 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -107,6 +107,59 @@ u64 timecounter_cyc2time(struct timecounter *tc, } EXPORT_SYMBOL(timecounter_cyc2time); +/** + * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks + * @mult: pointer to mult variable + * @shift: pointer to shift variable + * @from: frequency to convert from + * @to: frequency to convert to + * @minsec: guaranteed runtime conversion range in seconds + * + * The function evaluates the shift/mult pair for the scaled math + * operations of clocksources and clockevents. + * + * @to and @from are frequency values in HZ. For clock sources @to is + * NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock + * event @to is the counter frequency and @from is NSEC_PER_SEC. + * + * The @minsec conversion range argument controls the time frame in + * seconds which must be covered by the runtime conversion with the + * calculated mult and shift factors. This guarantees that no 64bit + * overflow happens when the input value of the conversion is + * multiplied with the calculated mult factor. Larger ranges may + * reduce the conversion accuracy by chosing smaller mult and shift + * factors. + */ +void +clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec) +{ + u64 tmp; + u32 sft, sftacc= 32; + + /* + * Calculate the shift factor which is limiting the conversion + * range: + */ + tmp = ((u64)minsec * from) >> 32; + while (tmp) { + tmp >>=1; + sftacc--; + } + + /* + * Find the conversion shift/mult pair which has the best + * accuracy and fits the maxsec conversion range: + */ + for (sft = 32; sft > 0; sft--) { + tmp = (u64) to << sft; + do_div(tmp, from); + if ((tmp >> sftacc) == 0) + break; + } + *mult = tmp; + *shift = sft; +} + /*[Clocksource internal variables]--------- * curr_clocksource: * currently selected clocksource. -- cgit v1.2.3 From 529eaccd900a59724619b4a6ef6579fd518d5218 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 13 Nov 2009 14:32:19 +0100 Subject: nohz: Type cast printk argument On some archs local_softirq_pending() has a data type of unsigned long on others its unsigned int. Type cast it to (unsigned int) in the printk to avoid the compiler warning. Signed-off-by: Thomas Gleixner LKML-Reference: --- kernel/time/tick-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3840f6dff7eb..c65ba0faa98f 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -250,7 +250,7 @@ void tick_nohz_stop_sched_tick(int inidle) if (ratelimit < 10) { printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", - local_softirq_pending()); + (unsigned int) local_softirq_pending()); ratelimit++; } goto end; -- cgit v1.2.3 From 98962465ed9e6ea99c38e0af63fe1dcb5a79dc25 Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Tue, 18 Aug 2009 12:45:10 -0500 Subject: nohz: Prevent clocksource wrapping during idle The dynamic tick allows the kernel to sleep for periods longer than a single tick, but it does not limit the sleep time currently. In the worst case the kernel could sleep longer than the wrap around time of the time keeping clock source which would result in losing track of time. Prevent this by limiting it to the safe maximum sleep time of the current time keeping clock source. The value is calculated when the clock source is registered. [ tglx: simplified the code a bit and massaged the commit msg ] Signed-off-by: Jon Hunter Cc: John Stultz LKML-Reference: <1250617512-23567-2-git-send-email-jon-hunter@ti.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 44 +++++++++++++++++++++++++++++++++++++++ kernel/time/tick-sched.c | 52 ++++++++++++++++++++++++++++++++++------------- kernel/time/timekeeping.c | 11 ++++++++++ 3 files changed, 93 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 407c0894ef37..b65b242f04dd 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -468,6 +468,47 @@ void clocksource_touch_watchdog(void) #ifdef CONFIG_GENERIC_TIME +/** + * clocksource_max_deferment - Returns max time the clocksource can be deferred + * @cs: Pointer to clocksource + * + */ +static u64 clocksource_max_deferment(struct clocksource *cs) +{ + u64 max_nsecs, max_cycles; + + /* + * Calculate the maximum number of cycles that we can pass to the + * cyc2ns function without overflowing a 64-bit signed result. The + * maximum number of cycles is equal to ULLONG_MAX/cs->mult which + * is equivalent to the below. + * max_cycles < (2^63)/cs->mult + * max_cycles < 2^(log2((2^63)/cs->mult)) + * max_cycles < 2^(log2(2^63) - log2(cs->mult)) + * max_cycles < 2^(63 - log2(cs->mult)) + * max_cycles < 1 << (63 - log2(cs->mult)) + * Please note that we add 1 to the result of the log2 to account for + * any rounding errors, ensure the above inequality is satisfied and + * no overflow will occur. + */ + max_cycles = 1ULL << (63 - (ilog2(cs->mult) + 1)); + + /* + * The actual maximum number of cycles we can defer the clocksource is + * determined by the minimum of max_cycles and cs->mask. + */ + max_cycles = min_t(u64, max_cycles, (u64) cs->mask); + max_nsecs = clocksource_cyc2ns(max_cycles, cs->mult, cs->shift); + + /* + * To ensure that the clocksource does not wrap whilst we are idle, + * limit the time the clocksource can be deferred by 12.5%. Please + * note a margin of 12.5% is used because this can be computed with + * a shift, versus say 10% which would require division. + */ + return max_nsecs - (max_nsecs >> 5); +} + /** * clocksource_select - Select the best clocksource available * @@ -564,6 +605,9 @@ static void clocksource_enqueue(struct clocksource *cs) */ int clocksource_register(struct clocksource *cs) { + /* calculate max idle time permitted for this clocksource */ + cs->max_idle_ns = clocksource_max_deferment(cs); + mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); clocksource_select(); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c65ba0faa98f..a80b4644fe6b 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -208,6 +208,7 @@ void tick_nohz_stop_sched_tick(int inidle) struct tick_sched *ts; ktime_t last_update, expires, now; struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; + u64 time_delta; int cpu; local_irq_save(flags); @@ -262,6 +263,17 @@ void tick_nohz_stop_sched_tick(int inidle) seq = read_seqbegin(&xtime_lock); last_update = last_jiffies_update; last_jiffies = jiffies; + + /* + * On SMP we really should only care for the CPU which + * has the do_timer duty assigned. All other CPUs can + * sleep as long as they want. + */ + if (cpu == tick_do_timer_cpu || + tick_do_timer_cpu == TICK_DO_TIMER_NONE) + time_delta = timekeeping_max_deferment(); + else + time_delta = KTIME_MAX; } while (read_seqretry(&xtime_lock, seq)); if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) || @@ -284,11 +296,26 @@ void tick_nohz_stop_sched_tick(int inidle) if ((long)delta_jiffies >= 1) { /* - * calculate the expiry time for the next timer wheel - * timer - */ - expires = ktime_add_ns(last_update, tick_period.tv64 * - delta_jiffies); + * calculate the expiry time for the next timer wheel + * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals + * that there is no timer pending or at least extremely + * far into the future (12 days for HZ=1000). In this + * case we set the expiry to the end of time. + */ + if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) { + /* + * Calculate the time delta for the next timer event. + * If the time delta exceeds the maximum time delta + * permitted by the current clocksource then adjust + * the time delta accordingly to ensure the + * clocksource does not wrap. + */ + time_delta = min_t(u64, time_delta, + tick_period.tv64 * delta_jiffies); + expires = ktime_add_ns(last_update, time_delta); + } else { + expires.tv64 = KTIME_MAX; + } /* * If this cpu is the one which updates jiffies, then @@ -332,22 +359,19 @@ void tick_nohz_stop_sched_tick(int inidle) ts->idle_sleeps++; + /* Mark expires */ + ts->idle_expires = expires; + /* - * delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that - * there is no timer pending or at least extremly far - * into the future (12 days for HZ=1000). In this case - * we simply stop the tick timer: + * If the expiration time == KTIME_MAX, then + * in this case we simply stop the tick timer. */ - if (unlikely(delta_jiffies >= NEXT_TIMER_MAX_DELTA)) { - ts->idle_expires.tv64 = KTIME_MAX; + if (unlikely(expires.tv64 == KTIME_MAX)) { if (ts->nohz_mode == NOHZ_MODE_HIGHRES) hrtimer_cancel(&ts->sched_timer); goto out; } - /* Mark expiries */ - ts->idle_expires = expires; - if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { hrtimer_start(&ts->sched_timer, expires, HRTIMER_MODE_ABS_PINNED); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 96b3f0dfa5dc..5d4d4239a0aa 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -477,6 +477,17 @@ int timekeeping_valid_for_hres(void) return ret; } +/** + * timekeeping_max_deferment - Returns max time the clocksource can be deferred + * + * Caller must observe xtime_lock via read_seqbegin/read_seqretry to + * ensure that the clocksource does not change! + */ +u64 timekeeping_max_deferment(void) +{ + return timekeeper.clock->max_idle_ns; +} + /** * read_persistent_clock - Return time from the persistent clock. * -- cgit v1.2.3 From 27185016b806d5a1181ff501cae120582b2b27dd Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 12 Nov 2009 22:12:06 +0100 Subject: nohz: Track last do_timer() cpu The previous patch which limits the sleep time to the maximum deferment time of the time keeping clocksource has some limitations on SMP machines: if all CPUs are idle then for all CPUs the maximum sleep time is limited. Solve this by keeping track of which cpu had the do_timer() duty assigned last and limit the sleep time only for this cpu. Signed-off-by: Thomas Gleixner LKML-Reference: Cc: Jon Hunter Cc: John Stultz --- kernel/time/tick-sched.c | 52 ++++++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 24 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index a80b4644fe6b..df133bc29f89 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -263,17 +263,7 @@ void tick_nohz_stop_sched_tick(int inidle) seq = read_seqbegin(&xtime_lock); last_update = last_jiffies_update; last_jiffies = jiffies; - - /* - * On SMP we really should only care for the CPU which - * has the do_timer duty assigned. All other CPUs can - * sleep as long as they want. - */ - if (cpu == tick_do_timer_cpu || - tick_do_timer_cpu == TICK_DO_TIMER_NONE) - time_delta = timekeeping_max_deferment(); - else - time_delta = KTIME_MAX; + time_delta = timekeeping_max_deferment(); } while (read_seqretry(&xtime_lock, seq)); if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) || @@ -295,6 +285,29 @@ void tick_nohz_stop_sched_tick(int inidle) /* Schedule the tick, if we are at least one jiffie off */ if ((long)delta_jiffies >= 1) { + /* + * If this cpu is the one which updates jiffies, then + * give up the assignment and let it be taken by the + * cpu which runs the tick timer next, which might be + * this cpu as well. If we don't drop this here the + * jiffies might be stale and do_timer() never + * invoked. Keep track of the fact that it was the one + * which had the do_timer() duty last. If this cpu is + * the one which had the do_timer() duty last, we + * limit the sleep time to the timekeeping + * max_deferement value which we retrieved + * above. Otherwise we can sleep as long as we want. + */ + if (cpu == tick_do_timer_cpu) { + tick_do_timer_cpu = TICK_DO_TIMER_NONE; + ts->do_timer_last = 1; + } else if (tick_do_timer_cpu != TICK_DO_TIMER_NONE) { + time_delta = KTIME_MAX; + ts->do_timer_last = 0; + } else if (!ts->do_timer_last) { + time_delta = KTIME_MAX; + } + /* * calculate the expiry time for the next timer wheel * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals @@ -312,21 +325,12 @@ void tick_nohz_stop_sched_tick(int inidle) */ time_delta = min_t(u64, time_delta, tick_period.tv64 * delta_jiffies); - expires = ktime_add_ns(last_update, time_delta); - } else { - expires.tv64 = KTIME_MAX; } - /* - * If this cpu is the one which updates jiffies, then - * give up the assignment and let it be taken by the - * cpu which runs the tick timer next, which might be - * this cpu as well. If we don't drop this here the - * jiffies might be stale and do_timer() never - * invoked. - */ - if (cpu == tick_do_timer_cpu) - tick_do_timer_cpu = TICK_DO_TIMER_NONE; + if (time_delta < KTIME_MAX) + expires = ktime_add_ns(last_update, time_delta); + else + expires.tv64 = KTIME_MAX; if (delta_jiffies > 1) cpumask_set_cpu(cpu, nohz_cpu_mask); -- cgit v1.2.3 From 97813f2fe77804a4464564c75ba8d8826377feea Mon Sep 17 00:00:00 2001 From: Jon Hunter Date: Tue, 18 Aug 2009 12:45:11 -0500 Subject: nohz: Allow 32-bit machines to sleep for more than 2.15 seconds In the dynamic tick code, "max_delta_ns" (member of the "clock_event_device" structure) represents the maximum sleep time that can occur between timer events in nanoseconds. The variable, "max_delta_ns", is defined as an unsigned long which is a 32-bit integer for 32-bit machines and a 64-bit integer for 64-bit machines (if -m64 option is used for gcc). The value of max_delta_ns is set by calling the function "clockevent_delta2ns()" which returns a maximum value of LONG_MAX. For a 32-bit machine LONG_MAX is equal to 0x7fffffff and in nanoseconds this equates to ~2.15 seconds. Hence, the maximum sleep time for a 32-bit machine is ~2.15 seconds, where as for a 64-bit machine it will be many years. This patch changes the type of max_delta_ns to be "u64" instead of "unsigned long" so that this variable is a 64-bit type for both 32-bit and 64-bit machines. It also changes the maximum value returned by clockevent_delta2ns() to KTIME_MAX. Hence this allows a 32-bit machine to sleep for longer than ~2.15 seconds. Please note that this patch also changes "min_delta_ns" to be "u64" too and although this is unnecessary, it makes the patch simpler as it avoids to fixup all callers of clockevent_delta2ns(). [ tglx: changed "unsigned long long" to u64 as we use this data type through out the time code ] Signed-off-by: Jon Hunter Cc: John Stultz LKML-Reference: <1250617512-23567-3-git-send-email-jon-hunter@ti.com> Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 3 ++- kernel/time/clockevents.c | 11 +++++------ kernel/time/tick-oneshot.c | 4 ++-- kernel/time/timer_list.c | 6 ++++-- 4 files changed, 13 insertions(+), 11 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 6d7020490f94..c215b74cd953 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1240,7 +1240,8 @@ hrtimer_interrupt_hanging(struct clock_event_device *dev, force_clock_reprogram = 1; dev->min_delta_ns = (unsigned long)try_time.tv64 * 3; printk(KERN_WARNING "hrtimer: interrupt too slow, " - "forcing clock min delta to %lu ns\n", dev->min_delta_ns); + "forcing clock min delta to %llu ns\n", + (unsigned long long) dev->min_delta_ns); } /* * High resolution timer interrupt diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 620b58abdc32..05e8aeedcdf3 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -37,10 +37,9 @@ static DEFINE_SPINLOCK(clockevents_lock); * * Math helper, returns latch value converted to nanoseconds (bound checked) */ -unsigned long clockevent_delta2ns(unsigned long latch, - struct clock_event_device *evt) +u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt) { - u64 clc = ((u64) latch << evt->shift); + u64 clc = (u64) latch << evt->shift; if (unlikely(!evt->mult)) { evt->mult = 1; @@ -50,10 +49,10 @@ unsigned long clockevent_delta2ns(unsigned long latch, do_div(clc, evt->mult); if (clc < 1000) clc = 1000; - if (clc > LONG_MAX) - clc = LONG_MAX; + if (clc > KTIME_MAX) + clc = KTIME_MAX; - return (unsigned long) clc; + return clc; } EXPORT_SYMBOL_GPL(clockevent_delta2ns); diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c index a96c0e2b89cf..0a8a213016f0 100644 --- a/kernel/time/tick-oneshot.c +++ b/kernel/time/tick-oneshot.c @@ -50,9 +50,9 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires, dev->min_delta_ns += dev->min_delta_ns >> 1; printk(KERN_WARNING - "CE: %s increasing min_delta_ns to %lu nsec\n", + "CE: %s increasing min_delta_ns to %llu nsec\n", dev->name ? dev->name : "?", - dev->min_delta_ns << 1); + (unsigned long long) dev->min_delta_ns << 1); i = 0; } diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index fa00da108a14..665c76edbf17 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -204,8 +204,10 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) return; } SEQ_printf(m, "%s\n", dev->name); - SEQ_printf(m, " max_delta_ns: %lu\n", dev->max_delta_ns); - SEQ_printf(m, " min_delta_ns: %lu\n", dev->min_delta_ns); + SEQ_printf(m, " max_delta_ns: %llu\n", + (unsigned long long) dev->max_delta_ns); + SEQ_printf(m, " min_delta_ns: %llu\n", + (unsigned long long) dev->min_delta_ns); SEQ_printf(m, " mult: %u\n", dev->mult); SEQ_printf(m, " shift: %u\n", dev->shift); SEQ_printf(m, " mode: %d\n", dev->mode); -- cgit v1.2.3 From a362c638bdf052bf424bce7645d39b101090f6ba Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 14 Nov 2009 00:26:34 +0100 Subject: clocksource/events: Fix fallout of generic code changes powerpc grew a new warning due to the type change of clockevent->mult. The architectures which use parts of the generic time keeping infrastructure tripped over my wrong assumption that clocksource_register is only used when GENERIC_TIME=y. I should have looked and also I should have known better. These renitent Gaul villages are racking my nerves. Some serious deprecating is due. Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index b65b242f04dd..72a2dcbd8b48 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -466,8 +466,6 @@ void clocksource_touch_watchdog(void) clocksource_resume_watchdog(); } -#ifdef CONFIG_GENERIC_TIME - /** * clocksource_max_deferment - Returns max time the clocksource can be deferred * @cs: Pointer to clocksource @@ -509,6 +507,8 @@ static u64 clocksource_max_deferment(struct clocksource *cs) return max_nsecs - (max_nsecs >> 5); } +#ifdef CONFIG_GENERIC_TIME + /** * clocksource_select - Select the best clocksource available * -- cgit v1.2.3 From dc186ad741c12ae9ecac8b89e317ef706fdaf8f6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 16 Nov 2009 01:09:48 +0900 Subject: workqueue: Add debugobjects support Add debugobject support to track the life time of work_structs. While at it, remove duplicate definition of INIT_DELAYED_WORK_ON_STACK(). Signed-off-by: Thomas Gleixner Signed-off-by: Tejun Heo --- kernel/workqueue.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 128 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 12328147132c..ddad63fbb61b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -68,6 +68,116 @@ struct workqueue_struct { #endif }; +#ifdef CONFIG_DEBUG_OBJECTS_WORK + +static struct debug_obj_descr work_debug_descr; + +/* + * fixup_init is called when: + * - an active object is initialized + */ +static int work_fixup_init(void *addr, enum debug_obj_state state) +{ + struct work_struct *work = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + cancel_work_sync(work); + debug_object_init(work, &work_debug_descr); + return 1; + default: + return 0; + } +} + +/* + * fixup_activate is called when: + * - an active object is activated + * - an unknown object is activated (might be a statically initialized object) + */ +static int work_fixup_activate(void *addr, enum debug_obj_state state) +{ + struct work_struct *work = addr; + + switch (state) { + + case ODEBUG_STATE_NOTAVAILABLE: + /* + * This is not really a fixup. The work struct was + * statically initialized. We just make sure that it + * is tracked in the object tracker. + */ + if (test_bit(WORK_STRUCT_STATIC, work_data_bits(work))) { + debug_object_init(work, &work_debug_descr); + debug_object_activate(work, &work_debug_descr); + return 0; + } + WARN_ON_ONCE(1); + return 0; + + case ODEBUG_STATE_ACTIVE: + WARN_ON(1); + + default: + return 0; + } +} + +/* + * fixup_free is called when: + * - an active object is freed + */ +static int work_fixup_free(void *addr, enum debug_obj_state state) +{ + struct work_struct *work = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + cancel_work_sync(work); + debug_object_free(work, &work_debug_descr); + return 1; + default: + return 0; + } +} + +static struct debug_obj_descr work_debug_descr = { + .name = "work_struct", + .fixup_init = work_fixup_init, + .fixup_activate = work_fixup_activate, + .fixup_free = work_fixup_free, +}; + +static inline void debug_work_activate(struct work_struct *work) +{ + debug_object_activate(work, &work_debug_descr); +} + +static inline void debug_work_deactivate(struct work_struct *work) +{ + debug_object_deactivate(work, &work_debug_descr); +} + +void __init_work(struct work_struct *work, int onstack) +{ + if (onstack) + debug_object_init_on_stack(work, &work_debug_descr); + else + debug_object_init(work, &work_debug_descr); +} +EXPORT_SYMBOL_GPL(__init_work); + +void destroy_work_on_stack(struct work_struct *work) +{ + debug_object_free(work, &work_debug_descr); +} +EXPORT_SYMBOL_GPL(destroy_work_on_stack); + +#else +static inline void debug_work_activate(struct work_struct *work) { } +static inline void debug_work_deactivate(struct work_struct *work) { } +#endif + /* Serializes the accesses to the list of workqueues. */ static DEFINE_SPINLOCK(workqueue_lock); static LIST_HEAD(workqueues); @@ -145,6 +255,7 @@ static void __queue_work(struct cpu_workqueue_struct *cwq, { unsigned long flags; + debug_work_activate(work); spin_lock_irqsave(&cwq->lock, flags); insert_work(cwq, work, &cwq->worklist); spin_unlock_irqrestore(&cwq->lock, flags); @@ -280,6 +391,7 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq) struct lockdep_map lockdep_map = work->lockdep_map; #endif trace_workqueue_execution(cwq->thread, work); + debug_work_deactivate(work); cwq->current_work = work; list_del_init(cwq->worklist.next); spin_unlock_irq(&cwq->lock); @@ -350,11 +462,18 @@ static void wq_barrier_func(struct work_struct *work) static void insert_wq_barrier(struct cpu_workqueue_struct *cwq, struct wq_barrier *barr, struct list_head *head) { - INIT_WORK(&barr->work, wq_barrier_func); + /* + * debugobject calls are safe here even with cwq->lock locked + * as we know for sure that this will not trigger any of the + * checks and call back into the fixup functions where we + * might deadlock. + */ + INIT_WORK_ON_STACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING, work_data_bits(&barr->work)); init_completion(&barr->done); + debug_work_activate(&barr->work); insert_work(cwq, &barr->work, head); } @@ -372,8 +491,10 @@ static int flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) } spin_unlock_irq(&cwq->lock); - if (active) + if (active) { wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); + } return active; } @@ -451,6 +572,7 @@ out: return 0; wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); return 1; } EXPORT_SYMBOL_GPL(flush_work); @@ -485,6 +607,7 @@ static int try_to_grab_pending(struct work_struct *work) */ smp_rmb(); if (cwq == get_wq_data(work)) { + debug_work_deactivate(work); list_del_init(&work->entry); ret = 1; } @@ -507,8 +630,10 @@ static void wait_on_cpu_work(struct cpu_workqueue_struct *cwq, } spin_unlock_irq(&cwq->lock); - if (unlikely(running)) + if (unlikely(running)) { wait_for_completion(&barr.done); + destroy_work_on_stack(&barr.work); + } } static void wait_on_work(struct work_struct *work) -- cgit v1.2.3 From 0696b711e4be45fa104c12329f617beb29c03f78 Mon Sep 17 00:00:00 2001 From: Lin Ming Date: Tue, 17 Nov 2009 13:49:50 +0800 Subject: timekeeping: Fix clock_gettime vsyscall time warp Since commit 0a544198 "timekeeping: Move NTP adjusted clock multiplier to struct timekeeper" the clock multiplier of vsyscall is updated with the unmodified clock multiplier of the clock source and not with the NTP adjusted multiplier of the timekeeper. This causes user space observerable time warps: new CLOCK-warp maximum: 120 nsecs, 00000025c337c537 -> 00000025c337c4bf Add a new argument "mult" to update_vsyscall() and hand in the timekeeping internal NTP adjusted multiplier. Signed-off-by: Lin Ming Cc: "Zhang Yanmin" Cc: Martin Schwidefsky Cc: Benjamin Herrenschmidt Cc: Tony Luck LKML-Reference: <1258436990.17765.83.camel@minggr.sh.intel.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c3a4e2907eaa..2a6d3e3e2c3e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -177,7 +177,7 @@ void timekeeping_leap_insert(int leapsecond) { xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; - update_vsyscall(&xtime, timekeeper.clock); + update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); } #ifdef CONFIG_GENERIC_TIME @@ -337,7 +337,7 @@ int do_settimeofday(struct timespec *tv) timekeeper.ntp_error = 0; ntp_clear(); - update_vsyscall(&xtime, timekeeper.clock); + update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -811,7 +811,7 @@ void update_wall_time(void) update_xtime_cache(nsecs); /* check to see if there is a new clocksource to use */ - update_vsyscall(&xtime, timekeeper.clock); + update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult); } /** -- cgit v1.2.3 From 8e1a928a2ed7e8d5cad97c8e985294b4caedd168 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Fri, 16 Oct 2009 18:19:01 -0400 Subject: clockevents: Add missing include to pacify sparse Include "tick-internal.h" in order to pick up the extern function prototype for clockevents_shutdown(). This quiets the following sparse build noise: warning: symbol 'clockevents_shutdown' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten LKML-Reference: Reviewed-by: Yong Zhang Cc: johnstul@us.ibm.com Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/time/clockevents.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 05e8aeedcdf3..20a8920029ee 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -20,6 +20,8 @@ #include #include +#include "tick-internal.h" + /* The registered clock event devices */ static LIST_HEAD(clockevent_devices); static LIST_HEAD(clockevents_released); -- cgit v1.2.3 From ba5ea951d0b5e5896180e21fe07f228d2b3b0e63 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 17 Nov 2009 14:14:13 -0800 Subject: posix-cpu-timers: optimize and document timer_create callback We have already new_timer initialized to all-zeros hence in function initializations are not needed. Document function expectation about new_timer argument as well. Signed-off-by: Stanislaw Gruszka Cc: johnstul@us.ibm.com Cc: Oleg Nesterov Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/posix-cpu-timers.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 5c9dc228747b..438ff4523513 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -384,7 +384,8 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) /* * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. - * This is called from sys_timer_create with the new timer already locked. + * This is called from sys_timer_create() and do_cpu_nanosleep() with the + * new timer already all-zeros initialized. */ int posix_cpu_timer_create(struct k_itimer *new_timer) { @@ -396,8 +397,6 @@ int posix_cpu_timer_create(struct k_itimer *new_timer) return -EINVAL; INIT_LIST_HEAD(&new_timer->it.cpu.entry); - new_timer->it.cpu.incr.sched = 0; - new_timer->it.cpu.expires.sched = 0; read_lock(&tasklist_lock); if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { -- cgit v1.2.3 From 8747d793fc5c4d3e4decd41d55f6dc24498dd5f5 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 17 Nov 2009 14:14:12 -0800 Subject: itimers: Fix racy writes to cpu_itimer fields incr_error and error fields of struct cpu_itimer are used when calculating next timer tick in check_cpu_itimers() and should not be modified without tsk->sighand->siglock taken. Signed-off-by: Stanislaw Gruszka LKML-Reference: <1253802903-979-1-git-send-email-sgruszka@redhat.com> Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Oleg Nesterov Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/itimer.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/itimer.c b/kernel/itimer.c index b03451ede528..d802883153da 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -146,6 +146,7 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, { cputime_t cval, nval, cinterval, ninterval; s64 ns_ninterval, ns_nval; + u32 error, incr_error; struct cpu_itimer *it = &tsk->signal->it[clock_id]; nval = timeval_to_cputime(&value->it_value); @@ -153,8 +154,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, ninterval = timeval_to_cputime(&value->it_interval); ns_ninterval = timeval_to_ns(&value->it_interval); - it->incr_error = cputime_sub_ns(ninterval, ns_ninterval); - it->error = cputime_sub_ns(nval, ns_nval); + error = cputime_sub_ns(nval, ns_nval); + incr_error = cputime_sub_ns(ninterval, ns_ninterval); spin_lock_irq(&tsk->sighand->siglock); @@ -168,6 +169,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, } it->expires = nval; it->incr = ninterval; + it->error = error; + it->incr_error = incr_error; trace_itimer_state(clock_id == CPUCLOCK_VIRT ? ITIMER_VIRTUAL : ITIMER_PROF, value, nval); -- cgit v1.2.3 From feae3203d711db0a9965300ee6d592257fdaae4f Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 17 Nov 2009 18:22:13 -0600 Subject: timers, init: Limit the number of per cpu calibration bootup messages Limit the number of per cpu calibration messages by only printing out results for the first cpu to boot. Also, don't print "CPUx is down" as this is expected, and we don't need 4096 reminders... ;-) Signed-off-by: Mike Travis Cc: Heiko Carstens Cc: Roland Dreier Cc: Randy Dunlap Cc: Tejun Heo Cc: Andi Kleen Cc: Greg Kroah-Hartman Cc: Yinghai Lu Cc: David Rientjes Cc: Steven Rostedt Cc: Rusty Russell Cc: Hidetoshi Seto Cc: Jack Steiner Cc: Frederic Weisbecker LKML-Reference: <20091118002219.889552000@alcatraz.americas.sgi.com> Signed-off-by: Ingo Molnar --- kernel/cpu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index 6ba0f1ecb212..7c4e2713df0a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -392,10 +392,9 @@ int disable_nonboot_cpus(void) if (cpu == first_cpu) continue; error = _cpu_down(cpu, 1); - if (!error) { + if (!error) cpumask_set_cpu(cpu, frozen_cpus); - printk("CPU%d is down\n", cpu); - } else { + else { printk(KERN_ERR "Error taking CPU%d down: %d\n", cpu, error); break; -- cgit v1.2.3 From 1786bf009f18f722afbb62143c8541e7e60a4e92 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 30 Nov 2009 12:54:51 +0200 Subject: core: Clean up user return notifers use of per_cpu Instead of using per_cpu(..., raw_smp_processor_id()), use __get_cpu_var(...). Signed-off-by: Avi Kivity LKML-Reference: <1259578491-4589-1-git-send-email-avi@redhat.com> Signed-off-by: Ingo Molnar --- kernel/user-return-notifier.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/user-return-notifier.c b/kernel/user-return-notifier.c index 03e2d6fd9b18..eb27fd3430a2 100644 --- a/kernel/user-return-notifier.c +++ b/kernel/user-return-notifier.c @@ -6,8 +6,6 @@ static DEFINE_PER_CPU(struct hlist_head, return_notifier_list); -#define URN_LIST_HEAD per_cpu(return_notifier_list, raw_smp_processor_id()) - /* * Request a notification when the current cpu returns to userspace. Must be * called in atomic context. The notifier will also be called in atomic @@ -16,7 +14,7 @@ static DEFINE_PER_CPU(struct hlist_head, return_notifier_list); void user_return_notifier_register(struct user_return_notifier *urn) { set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY); - hlist_add_head(&urn->link, &URN_LIST_HEAD); + hlist_add_head(&urn->link, &__get_cpu_var(return_notifier_list)); } EXPORT_SYMBOL_GPL(user_return_notifier_register); @@ -27,7 +25,7 @@ EXPORT_SYMBOL_GPL(user_return_notifier_register); void user_return_notifier_unregister(struct user_return_notifier *urn) { hlist_del(&urn->link); - if (hlist_empty(&URN_LIST_HEAD)) + if (hlist_empty(&__get_cpu_var(return_notifier_list))) clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY); } EXPORT_SYMBOL_GPL(user_return_notifier_unregister); -- cgit v1.2.3 From fb3d38b9904888aa8e36d88b2388dc70934b2169 Mon Sep 17 00:00:00 2001 From: Liuweni Date: Mon, 2 Nov 2009 15:55:03 +0100 Subject: fix kerneldoc for set_irq_msi() Signed-off-by: Liuweni Signed-off-by: Jiri Kosina --- kernel/irq/chip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index c1660194d115..ae70e93b29b5 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -166,11 +166,11 @@ int set_irq_data(unsigned int irq, void *data) EXPORT_SYMBOL(set_irq_data); /** - * set_irq_data - set irq type data for an irq + * set_irq_msi - set irq type data for an irq * @irq: Interrupt number * @entry: Pointer to MSI descriptor data * - * Set the hardware irq controller data for an irq + * Set the MSI descriptor entry for an irq */ int set_irq_msi(unsigned int irq, struct msi_desc *entry) { -- cgit v1.2.3 From fbfecd3712f917ca210a55c157233d88b785896b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 28 Oct 2009 20:11:04 +0100 Subject: tree-wide: fix typos "couter" -> "counter" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch was generated by git grep -E -i -l 'couter' | xargs -r perl -p -i -e 's/couter/counter/' Signed-off-by: Uwe Kleine-König Signed-off-by: Jiri Kosina --- kernel/irq/spurious.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 114e704760fe..abd4fb77f8ce 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -230,7 +230,7 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc, /* * If we are seeing only the odd spurious IRQ caused by * bus asynchronicity then don't eventually trigger an error, - * otherwise the couter becomes a doomsday timer for otherwise + * otherwise the counter becomes a doomsday timer for otherwise * working systems */ if (time_after(jiffies, desc->last_unhandled + HZ/10)) -- cgit v1.2.3 From af901ca181d92aac3a7dc265144a9081a86d8f39 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Goddard=20Rosa?= Date: Sat, 14 Nov 2009 13:09:05 -0200 Subject: tree-wide: fix assorted typos all over the place MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa Signed-off-by: Jiri Kosina --- kernel/perf_event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 7f29643c8985..759a629cc4bc 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -419,7 +419,7 @@ static void perf_event_remove_from_context(struct perf_event *event) if (!task) { /* * Per cpu events are removed via an smp call and - * the removal is always sucessful. + * the removal is always successful. */ smp_call_function_single(event->cpu, __perf_event_remove_from_context, @@ -827,7 +827,7 @@ perf_install_in_context(struct perf_event_context *ctx, if (!task) { /* * Per cpu events are installed via an smp call and - * the install is always sucessful. + * the install is always successful. */ smp_call_function_single(cpu, __perf_install_in_context, event, 1); -- cgit v1.2.3