Messages in this thread Patch in this message | | | Date | Tue, 28 Feb 2012 11:53:00 +0100 | From | Stephan Bärwolf <> | Subject | [PATCH] nitro: make multiplier scaleable, change "nitro_hzmultiplicator" into "nitro_hz_permille" |
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This patch extends the conventional "nitro_hzmultiplicator" into a permille-base. So now it is possible also to scale down HZ. (For example half HZ would be possible with nitro_hz_permille=500, a quarter nitro_hz_permille=250 ...etc...) As always, jiffies_64 increases with HZ frequency.
The new proc-file is called "nitro_hz_permille" The new config-option is called "CONFIG_SCHED_NITRO_HZBOOST_PERMILLE"
Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de> --- kernel/Kconfig.sched | 17 +++++++++-------- kernel/sysctl.c | 12 ++++++------ kernel/time/tick-common.c | 14 +++++++------- kernel/time/tick-internal.h | 19 ++++++++++++++----- 4 files changed, 36 insertions(+), 26 deletions(-)
diff --git a/kernel/Kconfig.sched b/kernel/Kconfig.sched index 27e5518..a066434 100644 --- a/kernel/Kconfig.sched +++ b/kernel/Kconfig.sched @@ -176,23 +176,24 @@ config SCHED_NITRO_HZBOOST_USERSPAC accessable from userspace via procfs. The responsible file will be called /proc/sys/kernel/nitro_hzmultiplicator
-config SCHED_NITRO_HZBOOST_MULTIPLICATOR - int "Multiply the HZ frequency value" - range 1 100 - default 1 +config SCHED_NITRO_HZBOOST_PERMILLE + int "Skale the HZ frequency value (per mille)" + range 1 100000 + default 1000 depends on (SCHED_NITRO_HZBOOST && X86_64 && SCHED_HRTICK) help Normally the scheduler code (scheduler_tick()) ticks with "HZ" frequency. With this frequency also "jiffies_64" is increased and is used by timerelated kernelcode. - This Option increases the schedulers tickerfrequency by multiplying - this multiplicator with HZ. However the jiffies_64 is STILL updated - with HZ-frequency and all the jiffy-based timecode is working further on. + This Option skales the schedulers tickerfrequency by multiplying + this per-mille value with HZ (and divides everything by 1000). + However the jiffies_64 is STILL updated with HZ-frequency and all the + jiffy-based timecode is working further on.
Asyncron ns-time-based code will take advantage from this option and scheduling will become finer and more interactive.
- WARNING: !! THIS OPTION WILL INCREASE YOUR "INTERRUPTS PER SECOND" FOR + WARNING: !! THIS OPTION MAY INCREASE YOUR "INTERRUPTS PER SECOND" FOR EACH ONLINE CPU. THIS WILL ALSO INCREASE YOUR SYSTEMOVERHEAD !! endmenu
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6c95dfe..f8cec40 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -253,8 +253,8 @@ static struct ctl_table root_table[] = {
#ifdef CONFIG_SCHED_NITRO_HZBOOST_USERSPAC #include "time/tick-internal.h" -static int min_tick_period_HZmultiplicator = 1; -static int max_tick_period_HZmultiplicator = 100; +static int min_tick_period_HZscalepermille = 1; +static int max_tick_period_HZscalepermille = 100000; #endif #ifdef CONFIG_SCHED_DEBUG static int min_sched_granularity_ns = 100000; /* 100 usecs */ @@ -280,13 +280,13 @@ static struct ctl_table kern_table[] = { }, #ifdef CONFIG_SCHED_NITRO_HZBOOST_USERSPAC { - .procname = "nitro_hzmultiplicator", - .data = &sysctl_tick_period_HZmultiplicator, + .procname = "nitro_hz_permille", + .data = &sysctl_tick_period_HZscalepermille, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = tick_change_periodmultiplicator_handler, - .extra1 = &min_tick_period_HZmultiplicator, - .extra2 = &max_tick_period_HZmultiplicator, + .extra1 = &min_tick_period_HZscalepermille, + .extra2 = &max_tick_period_HZscalepermille, }, #endif #ifdef CONFIG_SCHED_DEBUG diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 1c62de8..a0176e245 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -170,7 +170,7 @@ static void tick_setup_device(struct tick_device *td, tick_next_period = ktime_get(); #ifdef CONFIG_SCHED_NITRO_HZBOOST tick_HZbaseperiod = ktime_set(0, NSEC_PER_SEC / HZ); - tick_change_periodmultiplicator(CONFIG_SCHED_NITRO_HZBOOST_MULTIPLICATOR); + tick_change_periodmultiplicator(CONFIG_SCHED_NITRO_HZBOOST_PERMILLE); #else tick_period = ktime_set(0, NSEC_PER_SEC / HZ); #endif @@ -427,8 +427,8 @@ void __init tick_init(void) }
#ifdef CONFIG_SCHED_NITRO_HZBOOST_USERSPAC -unsigned int sysctl_tick_period_HZmultiplicator = ((unsigned long)CONFIG_SCHED_NITRO_HZBOOST_MULTIPLICATOR); -static unsigned int __last_HZmultiplicator = ((unsigned long)CONFIG_SCHED_NITRO_HZBOOST_MULTIPLICATOR); +unsigned int sysctl_tick_period_HZscalepermille = ((unsigned long)CONFIG_SCHED_NITRO_HZBOOST_PERMILLE); +static unsigned int __last_HZscalepermille = ((unsigned long)CONFIG_SCHED_NITRO_HZBOOST_PERMILLE);
int tick_change_periodmultiplicator_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, @@ -439,11 +439,11 @@ int tick_change_periodmultiplicator_handler(struct ctl_table *table, int write, if (ret || !write) return ret;
- if (sysctl_tick_period_HZmultiplicator > 0) - if (__last_HZmultiplicator != sysctl_tick_period_HZmultiplicator) { + if (sysctl_tick_period_HZscalepermille > 0) + if (__last_HZscalepermille != sysctl_tick_period_HZscalepermille) { write_seqlock(&xtime_lock); - tick_change_periodmultiplicator(sysctl_tick_period_HZmultiplicator); - __last_HZmultiplicator = sysctl_tick_period_HZmultiplicator; + tick_change_periodmultiplicator(sysctl_tick_period_HZscalepermille); + __last_HZscalepermille = sysctl_tick_period_HZscalepermille; write_sequnlock(&xtime_lock); }
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index eb60d32..26a1bda 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -17,19 +17,28 @@ extern int tick_do_timer_cpu __read_mostly; #ifdef CONFIG_SCHED_NITRO_HZBOOST extern ktime_t tick_HZbaseperiod; #ifdef CONFIG_SCHED_NITRO_HZBOOST_USERSPAC -extern unsigned int sysctl_tick_period_HZmultiplicator; +extern unsigned int sysctl_tick_period_HZscalepermille; extern int tick_change_periodmultiplicator_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); #endif /* * proper locking has to be taken care outside + * + * scalepermille better be not zero! + * */ -static inline void tick_change_periodmultiplicator(const unsigned long long multiplicator) +static inline void tick_change_periodmultiplicator(const unsigned long long scalepermille) { - printk( KERN_NOTICE "changing nitro hzboost multiplicator, new frequency: %llu x %lluHz\n", multiplicator, (unsigned long long)HZ); - tick_period = ktime_set(0, NSEC_PER_SEC / (HZ*multiplicator)); - printk( KERN_NOTICE "scheduler nitro-patchset v1.0 Ilmenau 2012, by Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>\n"); + unsigned long long __nanoseconds = (((unsigned long long)NSEC_PER_SEC) * 1000ULL) / scalepermille; + unsigned int i,j; + + i = scalepermille / 1000; + j = scalepermille % 1000; + + printk( KERN_NOTICE "changing nitro hzboost multiplicator, new frequency: %u.%03u x %lluHz\n", i, j, (unsigned long long)HZ); + tick_period = ktime_set(0, __nanoseconds / ((unsigned long long)HZ)); + printk( KERN_NOTICE "scheduler nitro-patchset v1.0.1 Ilmenau 2012, by Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de>\n"); } #endif
-- 1.7.3.4
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