Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 11 Nov 2001 16:15:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 11 Nov 2001 16:15:31 -0500 Received: from cc361913-a.flrtn1.occa.home.com ([24.0.193.171]:13449 "EHLO mirai.cx") by vger.kernel.org with ESMTP id ; Sun, 11 Nov 2001 16:15:24 -0500 Message-ID: <3BEEEA57.87D3F769@pobox.com> Date: Sun, 11 Nov 2001 13:15:03 -0800 From: J Sloan Organization: J S Concepts X-Mailer: Mozilla 4.78 [en] (X11; U; Linux 2.4.15-pre2 i686) X-Accept-Language: en MIME-Version: 1.0 To: Tim Schmielau CC: Linus Torvalds , linux-kernel@vger.kernel.org, J Sloan , Petr Vandrovec , george anzinger , "Richard B. Johnson" , Benjamin LaHaise Subject: Re: [Patch] enable uptime display > 497 days In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thank you for doing this labor of love - I will let you know how it goes sometime after March 23, 2003 - cu jjs Tim Schmielau wrote: > Dear Linus, > > the appended patch enables 32 bit linux boxes to display more than > 497.1 days of uptime. No user land application changes are needed. > This is the solution that came out of the "[Patch] Re: Nasty suprise with > uptime" thread a week ago. > > As no objections have been raised since then, and as I was able to cure > the observed lockups after jiffies wraparound by the "[Patch] fix > incorrect jiffies compares" just posted to lkml, I believe this to be > ready for inclusion into the main tree. > > The patch introduces a get_jiffies64() function that internally counts the > jiffies wrap. This way there is no overhead neither in the timer interrupt > nor in functions not interested in a 64bit jiffies value. IMHO this patch > does not interfere with the possible introduction of a "real" 64 bit > jiffies counter at later times, as the get_jiffies64() can still be > retained then to provide the necessary locking. > > I also extended the start_time field of struct task_struct to 64 bits so > that ps output will still be ok after the 32 bit wraparound while keeping > sub-second resolution of runtimes. > > Idle time overflow is dealt with in the same way as the jiffies > wraparound. The CPU time of the idle task will still overflow as it will > for every other process getting more than 497.1 days of CPU time, but I > don't want to blow up every time variable. I believe this to be acceptable > behavior. > > The downshot of counting jiffies wraps in get_jiffies64() is that > overflows get undetected if for more than 497 days > - /proc/uptime is not read, > - sysinfo() is not called, > - and no new processes are started, > which altogether is rather unlikely. > > Correct uptime display after jiffies wrap is of course only useful if > there are no stability problems after the wrap. To aid in finding out this > I added a config time option to initialize the jiffies counter to a value > 5 minutes before wrap. I kindly ask people to turn this on and watch out. > It did not affect stability for me anymore after the jiffies comparison > fixed were applied. > > Tim > > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/Documentation/Configure.help linux-2.4.15-pre2-jiffies64/Documentation/Configure.help > --- linux-2.4.15-pre2/Documentation/Configure.help Sun Nov 11 10:23:36 2001 > +++ linux-2.4.15-pre2-jiffies64/Documentation/Configure.help Sun Nov 11 10:40:13 2001 > @@ -23550,6 +23550,14 @@ > of the BUG call as well as the EIP and oops trace. This aids > debugging but costs about 70-100K of memory. > > +Debug jiffies counter wraparound (DANGEROUS) > +CONFIG_DEBUG_JIFFIESWRAP > + Say Y here to initialize the jiffies counter to a value 5 minutes > + before wraparound. This may make your system UNSTABLE and its > + only use is to hunt down the causes of this instability. > + If you don't know what the jiffies counter is or if you want > + a stable system, say N. > + > Include kgdb kernel debugger > CONFIG_KGDB > Include in-kernel hooks for kgdb, the Linux kernel source level > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/arm/config.in linux-2.4.15-pre2-jiffies64/arch/arm/config.in > --- linux-2.4.15-pre2/arch/arm/config.in Sun Nov 11 10:23:36 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/arm/config.in Sun Nov 11 10:40:13 2001 > @@ -601,6 +601,7 @@ > bool 'Magic SysRq key' CONFIG_MAGIC_SYSRQ > bool 'Spinlock debugging' CONFIG_DEBUG_SPINLOCK > dep_bool 'Disable pgtable cache' CONFIG_NO_PGT_CACHE $CONFIG_CPU_26 > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > # These options are only for real kernel hackers who want to get their hands dirty. > dep_bool 'Kernel low-level debugging functions' CONFIG_DEBUG_LL $CONFIG_EXPERIMENTAL > dep_bool ' Kernel low-level debugging messages via footbridge serial port' CONFIG_DEBUG_DC21285_PORT $CONFIG_DEBUG_LL $CONFIG_FOOTBRIDGE > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/cris/config.in linux-2.4.15-pre2-jiffies64/arch/cris/config.in > --- linux-2.4.15-pre2/arch/cris/config.in Mon Oct 15 22:42:14 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/cris/config.in Sun Nov 11 10:40:13 2001 > @@ -250,4 +250,5 @@ > if [ "$CONFIG_PROFILE" = "y" ]; then > int ' Profile shift count' CONFIG_PROFILE_SHIFT 2 > fi > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/i386/config.in linux-2.4.15-pre2-jiffies64/arch/i386/config.in > --- linux-2.4.15-pre2/arch/i386/config.in Sat Nov 3 02:46:47 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/i386/config.in Sun Nov 11 10:40:13 2001 > @@ -405,6 +405,7 @@ > bool ' Magic SysRq key' CONFIG_MAGIC_SYSRQ > bool ' Spinlock debugging' CONFIG_DEBUG_SPINLOCK > bool ' Verbose BUG() reporting (adds 70K)' CONFIG_DEBUG_BUGVERBOSE > + bool ' Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > fi > > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/m68k/config.in linux-2.4.15-pre2-jiffies64/arch/m68k/config.in > --- linux-2.4.15-pre2/arch/m68k/config.in Tue Jun 12 04:15:27 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/m68k/config.in Sun Nov 11 10:40:13 2001 > @@ -545,4 +545,5 @@ > > #bool 'Debug kmalloc/kfree' CONFIG_DEBUG_MALLOC > bool 'Magic SysRq key' CONFIG_MAGIC_SYSRQ > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/mips/config.in linux-2.4.15-pre2-jiffies64/arch/mips/config.in > --- linux-2.4.15-pre2/arch/mips/config.in Mon Oct 15 22:41:34 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/mips/config.in Sun Nov 11 10:40:13 2001 > @@ -519,4 +519,5 @@ > if [ "$CONFIG_SMP" != "y" ]; then > bool 'Run uncached' CONFIG_MIPS_UNCACHED > fi > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/parisc/config.in linux-2.4.15-pre2-jiffies64/arch/parisc/config.in > --- linux-2.4.15-pre2/arch/parisc/config.in Wed Apr 18 02:19:25 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/parisc/config.in Sun Nov 11 10:40:13 2001 > @@ -206,5 +206,6 @@ > > #bool 'Debug kmalloc/kfree' CONFIG_DEBUG_MALLOC > bool 'Magic SysRq key' CONFIG_MAGIC_SYSRQ > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/ppc/config.in linux-2.4.15-pre2-jiffies64/arch/ppc/config.in > --- linux-2.4.15-pre2/arch/ppc/config.in Sat Nov 3 02:43:54 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/ppc/config.in Sun Nov 11 10:40:13 2001 > @@ -391,4 +391,5 @@ > bool 'Magic SysRq key' CONFIG_MAGIC_SYSRQ > bool 'Include kgdb kernel debugger' CONFIG_KGDB > bool 'Include xmon kernel debugger' CONFIG_XMON > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/sh/config.in linux-2.4.15-pre2-jiffies64/arch/sh/config.in > --- linux-2.4.15-pre2/arch/sh/config.in Mon Oct 15 22:36:48 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/sh/config.in Sun Nov 11 10:40:13 2001 > @@ -385,4 +385,5 @@ > if [ "$CONFIG_SH_STANDARD_BIOS" = "y" ]; then > bool 'Early printk support' CONFIG_SH_EARLY_PRINTK > fi > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/arch/sparc/config.in linux-2.4.15-pre2-jiffies64/arch/sparc/config.in > --- linux-2.4.15-pre2/arch/sparc/config.in Tue Jun 12 04:15:27 2001 > +++ linux-2.4.15-pre2-jiffies64/arch/sparc/config.in Sun Nov 11 10:40:13 2001 > @@ -265,4 +265,5 @@ > comment 'Kernel hacking' > > bool 'Magic SysRq key' CONFIG_MAGIC_SYSRQ > +bool 'Debug jiffies counter wraparound (DANGEROUS)' CONFIG_DEBUG_JIFFIESWRAP > endmenu > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/fs/proc/array.c linux-2.4.15-pre2-jiffies64/fs/proc/array.c > --- linux-2.4.15-pre2/fs/proc/array.c Thu Oct 11 18:00:01 2001 > +++ linux-2.4.15-pre2-jiffies64/fs/proc/array.c Sun Nov 11 10:40:13 2001 > @@ -343,7 +343,7 @@ > ppid = task->pid ? task->p_opptr->pid : 0; > read_unlock(&tasklist_lock); > res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \ > -%lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %lu %lu %ld %lu %lu %lu %lu %lu \ > +%lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %llu %lu %ld %lu %lu %lu %lu %lu \ > %lu %lu %lu %lu %lu %lu %lu %lu %d %d\n", > task->pid, > task->comm, > @@ -366,7 +366,7 @@ > nice, > 0UL /* removed */, > task->it_real_value, > - task->start_time, > + (unsigned long long)(task->start_time) - INITIAL_JIFFIES, > vsize, > mm ? mm->rss : 0, /* you might want to shift this left 3 */ > task->rlim[RLIMIT_RSS].rlim_cur, > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/fs/proc/proc_misc.c linux-2.4.15-pre2-jiffies64/fs/proc/proc_misc.c > --- linux-2.4.15-pre2/fs/proc/proc_misc.c Thu Oct 11 19:46:57 2001 > +++ linux-2.4.15-pre2-jiffies64/fs/proc/proc_misc.c Sun Nov 11 10:40:14 2001 > @@ -39,6 +39,7 @@ > #include > #include > #include > +#include > > #define LOAD_INT(x) ((x) >> FSHIFT) > @@ -100,37 +101,59 @@ > return proc_calc_metrics(page, start, off, count, eof, len); > } > > +#if BITS_PER_LONG < 48 > + > +u64 get_idle64(void) > +{ > + static unsigned long idle_hi, idle_last; > + static spinlock_t idle64_lock = SPIN_LOCK_UNLOCKED; > + unsigned long idle; > + > + spin_lock(&idle64_lock); > + idle = init_tasks[0]->times.tms_utime + init_tasks[0]->times.tms_stime; > + if (idle < idle_last) /* We have a wrap */ > + idle_hi++; > + idle_last = idle; > + spin_unlock(&idle64_lock); > + > + return (idle | ((u64)idle_hi) << BITS_PER_LONG); > +} > + > +#else > + /* Idle time won't overflow for 8716 years at HZ==1024 */ > + > +static inline u64 get_idle64(void) > +{ > + return (u64)(init_tasks[0]->times.tms_utime > + + init_tasks[0]->times.tms_stime); > +} > + > +#endif /* BITS_PER_LONG < 48 */ > + > static int uptime_read_proc(char *page, char **start, off_t off, > int count, int *eof, void *data) > { > - unsigned long uptime; > - unsigned long idle; > + u64 uptime, idle; > + unsigned long uptime_remainder, idle_remainder; > int len; > > - uptime = jiffies; > - idle = init_tasks[0]->times.tms_utime + init_tasks[0]->times.tms_stime; > + uptime = get_jiffies64() - INITIAL_JIFFIES; > + uptime_remainder = (unsigned long) do_div(uptime, HZ); > + idle = get_idle64(); > + idle_remainder = (unsigned long) do_div(idle, HZ); > > - /* The formula for the fraction parts really is ((t * 100) / HZ) % 100, but > - that would overflow about every five days at HZ == 100. > - Therefore the identity a = (a / b) * b + a % b is used so that it is > - calculated as (((t / HZ) * 100) + ((t % HZ) * 100) / HZ) % 100. > - The part in front of the '+' always evaluates as 0 (mod 100). All divisions > - in the above formulas are truncating. For HZ being a power of 10, the > - calculations simplify to the version in the #else part (if the printf > - format is adapted to the same number of digits as zeroes in HZ. > - */ > #if HZ!=100 > len = sprintf(page,"%lu.%02lu %lu.%02lu\n", > - uptime / HZ, > - (((uptime % HZ) * 100) / HZ) % 100, > - idle / HZ, > - (((idle % HZ) * 100) / HZ) % 100); > + (unsigned long) uptime, > + (uptime_remainder * 100) / HZ, > + (unsigned long) idle, > + (idle_remainder * 100) / HZ); > #else > len = sprintf(page,"%lu.%02lu %lu.%02lu\n", > - uptime / HZ, > - uptime % HZ, > - idle / HZ, > - idle % HZ); > + (unsigned long) uptime, > + uptime_remainder, > + (unsigned long) idle, > + idle_remainder); > #endif > return proc_calc_metrics(page, start, off, count, eof, len); > } > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/include/linux/sched.h linux-2.4.15-pre2-jiffies64/include/linux/sched.h > --- linux-2.4.15-pre2/include/linux/sched.h Sun Nov 11 10:28:23 2001 > +++ linux-2.4.15-pre2-jiffies64/include/linux/sched.h Sun Nov 11 12:59:22 2001 > @@ -352,7 +352,7 @@ > unsigned long it_real_incr, it_prof_incr, it_virt_incr; > struct timer_list real_timer; > struct tms times; > - unsigned long start_time; > + u64 start_time; > long per_cpu_utime[NR_CPUS], per_cpu_stime[NR_CPUS]; > /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */ > unsigned long min_flt, maj_flt, nswap, cmin_flt, cmaj_flt, cnswap; > @@ -549,6 +549,8 @@ > #include > > extern unsigned long volatile jiffies; > +extern u64 get_jiffies64(void); > + > extern unsigned long itimer_ticks; > extern unsigned long itimer_next; > extern struct timeval xtime; > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/include/linux/timex.h linux-2.4.15-pre2-jiffies64/include/linux/timex.h > --- linux-2.4.15-pre2/include/linux/timex.h Mon Nov 5 21:42:13 2001 > +++ linux-2.4.15-pre2-jiffies64/include/linux/timex.h Sun Nov 11 12:54:00 2001 > @@ -53,6 +53,13 @@ > > #include > > +#ifdef CONFIG_DEBUG_JIFFIESWRAP > + /* Make the jiffies counter wrap around sooner. */ > +# define INITIAL_JIFFIES ((unsigned long)(-300*HZ)) > +#else > +# define INITIAL_JIFFIES 0 > +#endif > + > /* > * The following defines establish the engineering parameters of the PLL > * model. The HZ variable establishes the timer interrupt frequency, 100 Hz > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/kernel/acct.c linux-2.4.15-pre2-jiffies64/kernel/acct.c > --- linux-2.4.15-pre2/kernel/acct.c Mon Mar 19 21:35:08 2001 > +++ linux-2.4.15-pre2-jiffies64/kernel/acct.c Sun Nov 11 10:40:14 2001 > @@ -56,6 +56,7 @@ > #include > > #include > +#include > > /* > * These constants control the amount of freespace that suspend and > @@ -227,20 +228,24 @@ > * This routine has been adopted from the encode_comp_t() function in > * the kern_acct.c file of the FreeBSD operating system. The encoding > * is a 13-bit fraction with a 3-bit (base 8) exponent. > + * > + * Bumped up to encode 64 bit values. Unfortunately the result may > + * overflow now. > */ > > #define MANTSIZE 13 /* 13 bit mantissa. */ > -#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */ > +#define EXPSIZE 3 /* 3 bit exponent. */ > +#define EXPBASE 3 /* Base 8 (3 bit) exponent. */ > #define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */ > > -static comp_t encode_comp_t(unsigned long value) > +static comp_t encode_comp_t(u64 value) > { > int exp, rnd; > > exp = rnd = 0; > while (value > MAXFRACT) { > - rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */ > - value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */ > + rnd = value & (1 << (EXPBASE - 1)); /* Round up? */ > + value >>= EXPBASE; /* Base 8 exponent == 3 bit shift. */ > exp++; > } > > @@ -248,16 +253,21 @@ > * If we need to round up, do it (and handle overflow correctly). > */ > if (rnd && (++value > MAXFRACT)) { > - value >>= EXPSIZE; > + value >>= EXPBASE; > exp++; > } > > /* > * Clean it up and polish it off. > */ > - exp <<= MANTSIZE; /* Shift the exponent into place */ > - exp += value; /* and add on the mantissa. */ > - return exp; > + if (exp >= (1 << EXPSIZE)) { > + /* Overflow. Return largest representable number instead. */ > + return (1ul << (MANTSIZE + EXPSIZE)) - 1; > + } else { > + exp <<= MANTSIZE; /* Shift the exponent into place */ > + exp += value; /* and add on the mantissa. */ > + return exp; > + } > } > > /* > @@ -277,6 +287,7 @@ > struct acct ac; > mm_segment_t fs; > unsigned long vsize; > + u64 elapsed; > > /* > * First check to see if there is enough free_space to continue > @@ -294,8 +305,10 @@ > strncpy(ac.ac_comm, current->comm, ACCT_COMM); > ac.ac_comm[ACCT_COMM - 1] = '\0'; > > - ac.ac_btime = CT_TO_SECS(current->start_time) + (xtime.tv_sec - (jiffies / HZ)); > - ac.ac_etime = encode_comp_t(jiffies - current->start_time); > + elapsed = get_jiffies64() - current->start_time; > + ac.ac_etime = encode_comp_t(elapsed); > + do_div(elapsed, HZ); > + ac.ac_btime = xtime.tv_sec - elapsed; > ac.ac_utime = encode_comp_t(current->times.tms_utime); > ac.ac_stime = encode_comp_t(current->times.tms_stime); > ac.ac_uid = current->uid; > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/kernel/fork.c linux-2.4.15-pre2-jiffies64/kernel/fork.c > --- linux-2.4.15-pre2/kernel/fork.c Wed Oct 24 02:44:15 2001 > +++ linux-2.4.15-pre2-jiffies64/kernel/fork.c Sun Nov 11 10:40:14 2001 > @@ -647,7 +647,7 @@ > } > #endif > p->lock_depth = -1; /* -1 = no lock */ > - p->start_time = jiffies; > + p->start_time = get_jiffies64(); > > INIT_LIST_HEAD(&p->local_pages); > > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/kernel/info.c linux-2.4.15-pre2-jiffies64/kernel/info.c > --- linux-2.4.15-pre2/kernel/info.c Sat Apr 21 01:15:40 2001 > +++ linux-2.4.15-pre2-jiffies64/kernel/info.c Sun Nov 11 10:40:14 2001 > @@ -12,15 +12,19 @@ > #include > > #include > +#include > > asmlinkage long sys_sysinfo(struct sysinfo *info) > { > struct sysinfo val; > + u64 uptime; > > memset((char *)&val, 0, sizeof(struct sysinfo)); > > cli(); > - val.uptime = jiffies / HZ; > + uptime = get_jiffies64() - INITIAL_JIFFIES; > + do_div(uptime, HZ); > + val.uptime = (unsigned long) uptime; > > val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT); > val.loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT); > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/kernel/timer.c linux-2.4.15-pre2-jiffies64/kernel/timer.c > --- linux-2.4.15-pre2/kernel/timer.c Mon Oct 8 19:41:41 2001 > +++ linux-2.4.15-pre2-jiffies64/kernel/timer.c Sun Nov 11 13:05:25 2001 > @@ -65,7 +65,7 @@ > > extern int do_setitimer(int, struct itimerval *, struct itimerval *); > > -unsigned long volatile jiffies; > +unsigned long volatile jiffies = INITIAL_JIFFIES; > > unsigned int * prof_buffer; > unsigned long prof_len; > @@ -115,9 +115,17 @@ > } > for (i = 0; i < TVR_SIZE; i++) > INIT_LIST_HEAD(tv1.vec + i); > + > +#if CONFIG_DEBUG_JIFFIESWRAP > + tv1.index = INITIAL_JIFFIES & TVR_MASK; > + tv2.index = (INITIAL_JIFFIES >> TVR_BITS) & TVN_MASK; > + tv3.index = (INITIAL_JIFFIES >> (TVR_BITS + TVN_BITS)) & TVN_MASK; > + tv4.index = (INITIAL_JIFFIES >> (TVR_BITS + 2*TVN_BITS)) & TVN_MASK; > + tv5.index = (INITIAL_JIFFIES >> (TVR_BITS + 3*TVN_BITS)) & TVN_MASK; > +#endif > } > > -static unsigned long timer_jiffies; > +static unsigned long timer_jiffies = INITIAL_JIFFIES; > > static inline void internal_add_timer(struct timer_list *timer) > { > @@ -638,7 +646,7 @@ > } > > /* jiffies at the most recent update of wall time */ > -unsigned long wall_jiffies; > +unsigned long wall_jiffies = INITIAL_JIFFIES; > > /* > * This spinlock protect us from races in SMP while playing with xtime. -arca > @@ -683,6 +691,37 @@ > if (TQ_ACTIVE(tq_timer)) > mark_bh(TQUEUE_BH); > } > + > + > +#if BITS_PER_LONG < 48 > + > +u64 get_jiffies64(void) > +{ > + static unsigned long jiffies_hi = 0; > + static unsigned long jiffies_last = INITIAL_JIFFIES; > + static spinlock_t jiffies64_lock = SPIN_LOCK_UNLOCKED; > + unsigned long jiffies_tmp; > + > + spin_lock(&jiffies64_lock); > + jiffies_tmp = jiffies; /* avoid races */ > + if (jiffies_tmp < jiffies_last) /* We have a wrap */ > + jiffies_hi++; > + jiffies_last = jiffies_tmp; > + spin_unlock(&jiffies64_lock); > + > + return (jiffies_tmp | ((u64)jiffies_hi) << BITS_PER_LONG); > +} > + > +#else > + /* jiffies is wide enough to not wrap for 8716 years at HZ==1024 */ > + > +static inline u64 get_jiffies64(void) > +{ > + return (u64)jiffies; > +} > + > +#endif /* BITS_PER_LONG < 48 */ > + > > #if !defined(__alpha__) && !defined(__ia64__) > > diff -u -r --exclude-from dontdiff linux-2.4.15-pre2/mm/oom_kill.c linux-2.4.15-pre2-jiffies64/mm/oom_kill.c > --- linux-2.4.15-pre2/mm/oom_kill.c Sun Nov 4 02:05:25 2001 > +++ linux-2.4.15-pre2-jiffies64/mm/oom_kill.c Sun Nov 11 10:42:26 2001 > @@ -69,11 +69,10 @@ > /* > * CPU time is in seconds and run time is in minutes. There is no > * particular reason for this other than that it turned out to work > - * very well in practice. This is not safe against jiffie wraps > - * but we don't care _that_ much... > + * very well in practice. > */ > cpu_time = (p->times.tms_utime + p->times.tms_stime) >> (SHIFT_HZ + 3); > - run_time = (jiffies - p->start_time) >> (SHIFT_HZ + 10); > + run_time = (get_jiffies64() - p->start_time) >> (SHIFT_HZ + 10); > > points /= int_sqrt(cpu_time); > points /= int_sqrt(int_sqrt(run_time)); > > - > 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/ - 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/