High-res-timers part 1 (core) take 6
Subsystems (2)
PATCH 1/2 High-res-timers part 1 (core) take 6
This patch supplies the core changes to implement high resolution timers. Mostly it changes the timer list from the multi stage hash (or cascade) list to a single stage hash list. This change makes it easy to configure the list size for those who are concerned with performance. It also eliminates the "time out" for the cascade operation every 512 jiffies, thus eliminating possibly long preemption times.
It also adds a sub jiffie word to the timer structure to allow timers to exist between jiffies. However, to support the sub jiffie timers, work needs to be done in the platform code for each arch. The platform work for the i386 arch follows in part 2. To prevent requests from nonexistent code for sub jiffies stuff, these parts of this patch are disabled with the IF_HIGH_RES() macro which depends on CONFIG_HIGH_RES_TIMERS which will be defined for each platform as they supply the needed code.
Some of Ingo's timer code has been optimized to drop stuff not needed if the system is not SMP.
With this patch applied, the system should boot and run much as it does prior to the patch. This patch depends on the POSIX clocks & timers patch in that it assumes the changes that patch made to timer.c to remove timer_t. This dependency can be removed if needed.
Patch is against 2.5.43-bk1
Signature · 5 lines
George Anzinger [email protected] High-res-timers: http://sourceforge.net/projects/high-res-timers/ Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml
include/asm-i386/signal.h +9 -0
@@ -243,6 +243,15 @@#ifdef FOLD_NANO_SLEEP_INTO_CLOCK_NANO_SLEEP + +#ifndef _STRUCT_TIMESPEC +#define _STRUCT_TIMESPEC +struct timespec { +time_t tv_sec;/* seconds */ +long tv_nsec;/* nanoseconds */ +}; +#endif /* _STRUCT_TIMESPEC */ + extern long do_clock_nanosleep(struct pt_regs *regs, clockid_t which_clock, int flags,
include/linux/hrtime.h +156 -0
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include/linux/signal.h +29 -0
@@ -219,6 +219,35 @@ }extern long do_sigpending (void *,unsigned long ); +/* +* We would like the asm/signal.h code to define these so that the using +* function can call do_signal(). In loo of that, we define a genaric +* version that pretends that do_signal() was called and delivered a signal. +* To see how this is used, see nano_sleep() in timer.c and the i386 version +* in asm_i386/signal.h. +*/ +#ifndef PT_REGS_ENTRY +#define PT_REGS_ENTRY (type,name,p1_type,p1, p2_type,p2) \ +type name(p1_type p1,p2_type p2)\ +{ +#endif +#ifndef _do_signal +#define _do_signal () 1 +#endif +#ifndef NANOSLEEP_ENTRY +#define NANOSLEEP_ENTRY (a) asmlinkage long sys_nanosleep( struct timespec* rqtp, \ + struct timespec * rmtp) \ +{ a +#endif +#ifndef CLOCK_NANOSLEEP_ENTRY +#define CLOCK_NANOSLEEP_ENTRY (a) asmlinkage long sys_clock_nanosleep( \ + clockid_t which_clock, \ + int flags, \ + const struct timespec *rqtp, \ + struct timespec *rmtp) \ +{ a + +#endif #ifndef HAVE_ARCH_GET_SIGNAL_TO_DELIVER struct pt_regs ;
include/linux/time.h +22 -9
@@ -1,7 +1,7 @@#ifndef _LINUX_TIME_H#define _LINUX_TIME_H -#include <asm/param.h> +#include <linux/param.h> #include <linux/types.h> #ifndef _STRUCT_TIMESPEC
@@ -51,6 +51,19 @@#define NSEC_PER_USEC (1000L)#endif +/* Parameters used to convert the timespec values */ +#ifndef USEC_PER_SEC +#define USEC_PER_SEC (1000000L) +#endif + +#ifndef NSEC_PER_SEC +#define NSEC_PER_SEC (1000000000L) +#endif + +#ifndef NSEC_PER_USEC +#define NSEC_PER_USEC (1000L) +#endif +static __inline__unsigned long timespec_to_jiffies (struct timespec *value) {
@@ -59,16 +72,16 @@if (sec >= (MAX_JIFFY_OFFSET /HZ ))return MAX_JIFFY_OFFSET ; - nsec +=1000000000L /HZ -1 ; - nsec /=1000000000L /HZ ; + nsec +=NSEC_PER_SEC /HZ -1 ; + nsec /=NSEC_PER_SEC /HZ ;return HZ * sec + nsec; }static __inline__void -jiffies_to_timespec (unsigned long jiffies,struct timespec *value) +jiffies_to_timespec (unsigned long _jiffies,struct timespec *value) { - value->tv_nsec = (jiffies %HZ ) * (1000000000L /HZ ); - value->tv_sec = jiffies /HZ ; + value->tv_nsec = (_jiffies %HZ ) * (NSEC_PER_SEC /HZ ); + value->tv_sec = _jiffies /HZ ; }/* Same for "timeval" */
@@ -155,9 +168,9 @@#define ITIMER_VIRTUAL 1#define ITIMER_PROF 2 -struct itimerspec { -struct timespec it_interval;/* timer period */ -struct timespec it_value;/* timer expiration */ +struct itimerspec { +struct timespec it_interval;/* timer period */ +struct timespec it_value;/* timer expiration */ };struct itimerval {
include/linux/timer.h +2 -0
@@ -14,6 +14,7 @@unsigned long data;struct tvec_t_base_s *base; +long sub_expires; };/***
@@ -46,6 +47,7 @@extern void add_timer (struct timer_list * timer);extern int del_timer (struct timer_list * timer);extern int mod_timer (struct timer_list *timer,unsigned long expires); +extern void update_real_wall_time (void );#if CONFIG_SMP extern int del_timer_sync (struct timer_list * timer);
init/Config.in +21 -0
@@ -9,6 +9,27 @@ bool 'System V IPC' CONFIG_SYSVIPC bool 'BSD Process Accounting' CONFIG_BSD_PROCESS_ACCT bool 'Sysctl support' CONFIG_SYSCTL +choice 'Size of timer list?' \ + "512 CONFIG_TIMERLIST_512 \ + 1024 CONFIG_TIMERLIST_1k \ + 2048 CONFIG_TIMERLIST_2k \ + 4096 CONFIG_TIMERLIST_4k \ + 8192 CONFIG_TIMERLIST_8k" 512 +if [ "$CONFIG_TIMERLIST_512" = "y" ]; then + define_int CONFIG_NEW_TIMER_LISTSIZE 512 +fi +if [ "$CONFIG_TIMERLIST_1k" = "y" ]; then + define_int CONFIG_NEW_TIMER_LISTSIZE 1024 +fi +if [ "$CONFIG_TIMERLIST_2k" = "y" ]; then + define_int CONFIG_NEW_TIMER_LISTSIZE 2048 +fi +if [ "$CONFIG_TIMERLIST_4k" = "y" ]; then + define_int CONFIG_NEW_TIMER_LISTSIZE 4096 +fi +if [ "$CONFIG_TIMERLIST_8k" = "y" ]; then + define_int CONFIG_NEW_TIMER_LISTSIZE 8192 +fi int 'System wide maximum number of POSIX timers' CONFIG_MAX_POSIX_TIMERS 3000 endmenu
kernel/ksyms.c +2 -0
@@ -54,6 +54,7 @@#include <linux/smp_lock.h> #include <linux/dnotify.h> #include <asm/checksum.h> +#include <linux/hrtime.h> #if defined(CONFIG_PROC_FS )#include <linux/proc_fs.h>
@@ -483,6 +484,7 @@#endif EXPORT_SYMBOL (jiffies);EXPORT_SYMBOL (jiffies_64); +EXPORT_SYMBOL (timer_conversion_bits);EXPORT_SYMBOL (xtime);EXPORT_SYMBOL (do_gettimeofday);EXPORT_SYMBOL (do_settimeofday);
kernel/timer.c +372 -161
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