From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by vger.rutgers.edu id <972010-26836>; Mon, 13 Jul 1998 16:20:54 -0400 Received: from val5-237.abo.wanadoo.fr ([193.252.200.237]:62209 "EHLO lw2l.bnc.interdrome.fr" ident: "IDENT-NONSENSE") by vger.rutgers.edu with ESMTP id <972134-26836>; Mon, 13 Jul 1998 15:54:38 -0400 From: Andrew Derrick Balsa Reply-To: andrebalsa@altern.org To: "C. Scott Ananian" Subject: Re: new version of time.c Date: Mon, 13 Jul 1998 22:50:25 +0200 X-Mailer: KMail [version 0.7.9] Content-Type: Multipart/Mixed; boundary="Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd" Cc: linux-kernel@vger.rutgers.edu, Philip Gladstone References: MIME-Version: 1.0 Message-Id: <98071323124800.00482@lw2l.bnc.interdrome.fr> Sender: owner-linux-kernel@vger.rutgers.edu --Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd Content-Type: text/plain Content-Transfer-Encoding: 8bit Hi Scott, Philip, On Mon, 13 Jul 1998, C. Scott Ananian wrote: >On Mon, 13 Jul 1998, Philip Gladstone wrote: > >> Actually, I'm now getting concerned about interrupts happening >> between doing the LATCH and the RDTSC. [pause to try an experiment] >> >> Yup -- adding a cli() / restore pair around the crucial code >> in pentium_timer_interrupt helps a lot. > >Makes sense. Now we ought to start integrating/cleaning all these >patches, test suites, and ideas. Good Idea. :-) So I integrated Philip's code with the new time.c code for 2.0.x. Recompiled the kernel and am running it right now. So far so good, whether I turn on the Cyrix suspend-on-halt feature or not. :-) And tested it using Philip's pent_time.c test code. If I test it with suspend-on-halt ON, I get a quotient value of zero, hence a division by zero and of course the seg fault and core dump. This was expected, since it's exactly what the "old" time.c code did. :-) If I test with suspend-on-halt OFF, I get the attached sample output. (all tests made from within an xterm, on a relatively idle box). I am also attaching the "new" time.c. It's a drop-in replacement for the /arch/i386/kernel/time.c in 2.0.32, 2.0.33 and 2.0.34. Finally, I am attaching my /proc/cpuinfo; needs a small patch to setup.c... once you install the new time.c code, obviously ;-) Cheers, --------------------- Andrew D. Balsa andrebalsa@altern.org --Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd Content-Type: text/x-c; name="time.c" Content-Transfer-Encoding: 8bit Content-Description: A drop-in replacement for /arch/i386/kernel/time.c Content-Disposition: attachment; filename="time.c" /* * linux/arch/i386/kernel/time.c * * Copyright (C) 1991, 1992, 1995 Linus Torvalds * * This file contains the PC-specific time handling details: * reading the RTC at bootup, etc.. * 1994-07-02 Alan Modra * fixed set_rtc_mmss, fixed time.year for >= 2000, new mktime * 1995-03-26 Markus Kuhn * fixed 500 ms bug at call to set_rtc_mmss, fixed DS12887 * precision CMOS clock update * 1996-05-03 Ingo Molnar * fixed time warps in do_[slow|fast]_gettimeoffset() * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 * "A Kernel Model for Precision Timekeeping" by Dave Mills * 1998-05-23 C. Scott Ananian & Andrew D. Balsa * More robust do_fast_gettimeoffset() algorithm implemented * (works with APM, Cyrix 6x86MX and Centaur C6), * drift-proof precision TSC calibration on boot. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern int setup_x86_irq(int, struct irqaction *); unsigned long cpu_hz; /* Detected as we calibrate the TSC */ /* Number of usecs that the last interrupt was delayed */ static int delay_at_last_interrupt; static unsigned long last_tsc_low; /* lsb 32 bits of Time Stamp Counter */ /* Cached *multiplier* to convert TSC counts to microseconds. * (see the equation below). * Equal to 2^32 * (1 / (clocks per usec) ). * Initialized in time_init. */ static unsigned long fast_gettimeoffset_quotient=0; static unsigned long do_fast_gettimeoffset(void) { register unsigned long eax asm("ax"); register unsigned long edx asm("dx"); /* Read the Time Stamp Counter */ __asm__(".byte 0x0f,0x31" :"=a" (eax), "=d" (edx)); /* .. relative to previous jiffy (32 bits is enough) */ edx = 0; eax -= last_tsc_low; /* tsc_low delta */ /* * Time offset = (tsc_low delta) * fast_gettimeoffset_quotient. * = (tsc_low delta) / (clocks_per_usec) * = (tsc_low delta) / (clocks_per_jiffy / usecs_per_jiffy) * * Using a mull instead of a divl saves up to 31 clock cycles * in the critical path. */ __asm__("mull %2" :"=a" (eax), "=d" (edx) :"r" (fast_gettimeoffset_quotient), "0" (eax), "1" (edx)); /* * Due to rounding errors (and jiffies inconsistencies), * we need to check the result so that we'll get a timer * that is monotonic. * * We have a problem here, because this should _never_ * happen: we read the TSC at each timer interrupt in * the interrupt handler (see pentium_timer_interrupt below), * not in the bottom half handler. * The problem is that some drivers may disable interrupts, * then do all their I/O stuff which takes some time, * and then call gettimeofday() without restoring the * interrupts status again. */ if (edx >= 1000020/HZ) edx = 1000020/HZ-1; /* At this point we hope that gettimeofday() * isn't called again before the next * timer interrupt updates last_timer_cc * (we would get twice the same timestamp). */ return edx + delay_at_last_interrupt; /* our time offset in microseconds */ } /* This function must be called with interrupts disabled * It was inspired by Steve McCanne's microtime-i386 for BSD. -- jrs * * However, the pc-audio speaker driver changes the divisor so that * it gets interrupted rather more often - it loads 64 into the * counter rather than 11932! This has an adverse impact on * do_gettimeoffset() -- it stops working! What is also not * good is that the interval that our timer function gets called * is no longer 10.0002 ms, but 9.9767 ms. To get around this * would require using a different timing source. Maybe someone * could use the RTC - I know that this can interrupt at frequencies * ranging from 8192Hz to 2Hz. If I had the energy, I'd somehow fix * it so that at startup, the timer code in sched.c would select * using either the RTC or the 8253 timer. The decision would be * based on whether there was any other device around that needed * to trample on the 8253. I'd set up the RTC to interrupt at 1024 Hz, * and then do some jiggery to have a version of do_timer that * advanced the clock by 1/1024 s. Every time that reached over 1/100 * of a second, then do all the old code. If the time was kept correct * then do_gettimeoffset could just return 0 - there is no low order * divider that can be accessed. * * Ideally, you would be able to use the RTC for the speaker driver, * but it appears that the speaker driver really needs interrupt more * often than every 120 us or so. * * Anyway, this needs more thought.... pjsg (1993-08-28) * * If you are really that interested, you should be reading * comp.protocols.time.ntp! */ #define TICK_SIZE tick static unsigned long do_slow_gettimeoffset(void) { int count; static int count_p = 0; unsigned long offset = 0; static unsigned long jiffies_p = 0; /* * cache volatile jiffies temporarily; we have IRQs turned off. */ unsigned long jiffies_t; /* timer count may underflow right here */ outb_p(0x00, 0x43); /* latch the count ASAP */ count = inb_p(0x40); /* read the latched count */ count |= inb(0x40) << 8; jiffies_t = jiffies; /* * avoiding timer inconsistencies (they are rare, but they happen)... * there are three kinds of problems that must be avoided here: * 1. the timer counter underflows * 2. hardware problem with the timer, not giving us continuous time, * the counter does small "jumps" upwards on some Pentium systems, * thus causes time warps * 3. we are after the timer interrupt, but the bottom half handler * hasn't executed yet. */ if( count > count_p ) { if( jiffies_t == jiffies_p ) { if( count > LATCH-LATCH/100 ) offset = TICK_SIZE; else /* * argh, the timer is bugging we cant do nothing * but to give the previous clock value. */ count = count_p; } else { if( test_bit(TIMER_BH, &bh_active) ) { /* * we have detected a counter underflow. */ offset = TICK_SIZE; count_p = count; } else { count_p = count; jiffies_p = jiffies_t; } } } else { count_p = count; jiffies_p = jiffies_t; } count = ((LATCH-1) - count) * TICK_SIZE; count = (count + LATCH/2) / LATCH; return offset + count; } static unsigned long (*do_gettimeoffset)(void) = do_slow_gettimeoffset; /* * This version of gettimeofday has microsecond resolution * and better than microsecond precision on fast x86 machines with TSC. */ void do_gettimeofday(struct timeval *tv) { unsigned long flags; save_flags(flags); cli(); *tv = xtime; tv->tv_usec += do_gettimeoffset(); if (tv->tv_usec >= 1000000) { tv->tv_usec -= 1000000; tv->tv_sec++; } restore_flags(flags); } void do_settimeofday(struct timeval *tv) { cli(); /* This is revolting. We need to set the xtime.tv_usec * correctly. However, the value in this location is * is value at the last tick. * Discover what correction gettimeofday * would have done, and then undo it! */ tv->tv_usec -= do_gettimeoffset(); if (tv->tv_usec < 0) { tv->tv_usec += 1000000; tv->tv_sec--; } xtime = *tv; time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_state = TIME_ERROR; /* p. 24, (a) */ time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; sti(); } /* * In order to set the CMOS clock precisely, set_rtc_mmss has to be * called 500 ms after the second nowtime has started, because when * nowtime is written into the registers of the CMOS clock, it will * jump to the next second precisely 500 ms later. Check the Motorola * MC146818A or Dallas DS12887 data sheet for details. * * BUG: This routine does not handle hour overflow properly; it just * sets the minutes. Usually you'll only notice that after reboot! */ static int set_rtc_mmss(unsigned long nowtime) { int retval = 0; int real_seconds, real_minutes, cmos_minutes; unsigned char save_control, save_freq_select; save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */ CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */ CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); cmos_minutes = CMOS_READ(RTC_MINUTES); if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) BCD_TO_BIN(cmos_minutes); /* * since we're only adjusting minutes and seconds, * don't interfere with hour overflow. This avoids * messing with unknown time zones but requires your * RTC not to be off by more than 15 minutes */ real_seconds = nowtime % 60; real_minutes = nowtime / 60; if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) real_minutes += 30; /* correct for half hour time zone */ real_minutes %= 60; if (abs(real_minutes - cmos_minutes) < 30) { if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BIN_TO_BCD(real_seconds); BIN_TO_BCD(real_minutes); } CMOS_WRITE(real_seconds,RTC_SECONDS); CMOS_WRITE(real_minutes,RTC_MINUTES); } else { printk(KERN_WARNING "set_rtc_mmss: can't update from %d to %d\n", cmos_minutes, real_minutes); retval = -1; } /* The following flags have to be released exactly in this order, * otherwise the DS12887 (popular MC146818A clone with integrated * battery and quartz) will not reset the oscillator and will not * update precisely 500 ms later. You won't find this mentioned in * the Dallas Semiconductor data sheets, but who believes data * sheets anyway ... -- Markus Kuhn */ CMOS_WRITE(save_control, RTC_CONTROL); CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); return retval; } /* last time the cmos clock got updated */ static long last_rtc_update = 0; /* * timer_interrupt() needs to keep up the real-time clock, * as well as call the "do_timer()" routine every clocktick */ static inline void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { do_timer(regs); /* * If we have an externally synchronized Linux clock, then update * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be * called as close as possible to 500 ms before the new second starts. */ if ((time_status & STA_UNSYNC) == 0 && xtime.tv_sec > last_rtc_update + 660 && xtime.tv_usec > 500000 - (tick >> 1) && xtime.tv_usec < 500000 + (tick >> 1)) if (set_rtc_mmss(xtime.tv_sec) == 0) last_rtc_update = xtime.tv_sec; else last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ /* As we return to user mode fire off the other CPU schedulers.. this is basically because we don't yet share IRQ's around. This message is rigged to be safe on the 386 - basically it's a hack, so don't look closely for now.. */ /*smp_message_pass(MSG_ALL_BUT_SELF, MSG_RESCHEDULE, 0L, 0); */ } /* * This is the same as the above, except we _also_ save the current * Time Stamp Counter value at the time of the timer interrupt, so that * we later on can estimate the time of day more exactly. */ static void pentium_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { register unsigned long edx asm("dx"); int count, flags; /* It is important that these two operations happen almost at the * same time. We do the RDTSC stuff first, since it's faster. To * avoid any inconsistencies, we disable interrupts. */ save_flags(flags); cli(); /* read Pentium cycle counter */ __asm__(".byte 0x0f,0x31" :"=a" (last_tsc_low), "=d" (edx)); outb_p(0x00, 0x43); /* latch the count ASAP */ restore_flags(flags); count = inb_p(0x40); /* read the latched count */ count |= inb(0x40) << 8; count = ((LATCH-1) - count) * TICK_SIZE; delay_at_last_interrupt = (count + LATCH/2) / LATCH; timer_interrupt(irq, NULL, regs); } /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. * * [For the Julian calendar (which was used in Russia before 1917, * Britain & colonies before 1752, anywhere else before 1582, * and is still in use by some communities) leave out the * -year/100+year/400 terms, and add 10.] * * This algorithm was first published by Gauss (I think). * * WARNING: this function will overflow on 2106-02-07 06:28:16 on * machines were long is 32-bit! (However, as time_t is signed, we * will already get problems at other places on 2038-01-19 03:14:08) */ static inline unsigned long mktime(unsigned int year, unsigned int mon, unsigned int day, unsigned int hour, unsigned int min, unsigned int sec) { if (0 >= (int) (mon -= 2)) { /* 1..12 -> 11,12,1..10 */ mon += 12; /* Puts Feb last since it has leap day */ year -= 1; } return ((( (unsigned long)(year/4 - year/100 + year/400 + 367*mon/12 + day) + year*365 - 719499 )*24 + hour /* now have hours */ )*60 + min /* now have minutes */ )*60 + sec; /* finally seconds */ } unsigned long get_cmos_time(void) { unsigned int year, mon, day, hour, min, sec; int i; /* The Linux interpretation of the CMOS clock register contents: * When the Update-In-Progress (UIP) flag goes from 1 to 0, the * RTC registers show the second which has precisely just started. * Let's hope other operating systems interpret the RTC the same way. */ /* read RTC exactly on falling edge of update flag */ for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */ if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP) break; for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */ if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) break; do { /* Isn't this overkill ? UIP above should guarantee consistency */ sec = CMOS_READ(RTC_SECONDS); min = CMOS_READ(RTC_MINUTES); hour = CMOS_READ(RTC_HOURS); day = CMOS_READ(RTC_DAY_OF_MONTH); mon = CMOS_READ(RTC_MONTH); year = CMOS_READ(RTC_YEAR); } while (sec != CMOS_READ(RTC_SECONDS)); if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { BCD_TO_BIN(sec); BCD_TO_BIN(min); BCD_TO_BIN(hour); BCD_TO_BIN(day); BCD_TO_BIN(mon); BCD_TO_BIN(year); } if ((year += 1900) < 1970) year += 100; return mktime(year, mon, day, hour, min, sec); } static struct irqaction irq0 = { timer_interrupt, 0, 0, "timer", NULL, NULL}; /* ------ Calibrate the TSC ------- * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset(). * Too much 64-bit arithmetic here to do this cleanly in C, and for * accuracy's sake we want to keep the overhead on the CTC speaker (channel 2) * output busy loop as low as possible. We avoid reading the CTC registers * directly because of the awkward 8-bit access mechanism of the 82C54 * device. */ static unsigned long calibrate_tsc(void) { unsigned long retval; __asm__( /* set the Gate high, program CTC channel 2 for mode 0 * (interrupt on terminal count mode), binary count, * load 5 * LATCH count, (LSB and MSB) * to begin countdown, read the TSC and busy wait. * BTW LATCH is calculated in timex.h from the HZ value */ /* Set the Gate high, disable speaker */ "inb $0x61, %%al\n\t" /* Read port */ "andb $0xfd, %%al\n\t" /* Turn off speaker Data */ "orb $0x01, %%al\n\t" /* Set Gate high */ "outb %%al, $0x61\n\t" /* Write port */ /* Now let's take care of CTC channel 2 */ "movb $0xb0, %%al\n\t" /* binary, mode 0, LSB/MSB, ch 2*/ "outb %%al, $0x43\n\t" /* Write to CTC command port */ "movb $0x0c, %%al\n\t" "outb %%al, $0x42\n\t" /* LSB of count */ "movb $0xe9, %%al\n\t" "outb %%al, $0x42\n\t" /* MSB of count */ /* Read the TSC; counting has just started */ "rdtsc\n\t" /* Move the value for safe-keeping. */ "movl %%eax, %%ebx\n\t" "movl %%edx, %%ecx\n\t" /* Busy wait. Only 50 ms wasted at boot time. */ "0: inb $0x61, %%al\n\t" /* Read Speaker Output Port */ "testb $0x20, %%al\n\t" /* Check CTC channel 2 output (bit 5) */ "jz 0b\n\t" /* And read the TSC. 5 jiffies (50.00077ms) have elapsed. */ "rdtsc\n\t" /* Great. So far so good. Store last TSC reading in * last_tsc_low (only 32 lsb bits needed) */ "movl %%eax, last_tsc_low\n\t" /* And now calculate the difference between the readings. */ "subl %%ebx, %%eax\n\t" "sbbl %%ecx, %%edx\n\t" /* 64-bit subtract */ /* but probably edx = 0 at this point (see below). */ /* Now we have 5 * (TSC counts per jiffy) in eax. We want * to calculate TSC->microsecond conversion factor. */ /* Note that edx (high 32-bits of difference) will now be * zero iff CPU clock speed is less than 85 GHz. Moore's * law says that this is likely to be true for the next * 12 years or so. You will have to change this code to * do a real 64-by-64 divide before that time's up. */ "movl %%eax, %%ecx\n\t" "xorl %%eax, %%eax\n\t" "movl %1, %%edx\n\t" "divl %%ecx\n\t" /* eax= 2^32 / (1 * TSC counts per microsecond) */ /* Return eax for the use of fast_gettimeoffset */ "movl %%eax, %0\n\t" : "=r" (retval) : "r" (5 * 1000020/HZ) : /* we clobber: */ "ax", "bx", "cx", "dx", "cc", "memory"); return retval; } void time_init(void) { xtime.tv_sec = get_cmos_time(); xtime.tv_usec = 0; /* * If we have APM enabled or the CPU clock speed is variable * (CPU stops clock on HLT or slows clock to save power) * then the TSC timestamps may diverge by up to 1 jiffy from * 'real time' but nothing will break. * The most frequent case is that the CPU is "woken" from a halt * state by the timer interrupt itself, so we get 0 error. In the * rare cases where a driver would "wake" the CPU and request a * timestamp, the maximum error is < 1 jiffy. But timestamps are * still perfectly ordered. * Note that the TSC counter will be reset if APM suspends * to disk; this won't break the kernel, though, 'cuz we're * smart. See devices/char/apm_bios.c. */ if (x86_capability & 16) { do_gettimeoffset = do_fast_gettimeoffset; irq0.handler = pentium_timer_interrupt; fast_gettimeoffset_quotient = calibrate_tsc(); /* report CPU clock rate in Hz. * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) = * clock/second. Our precision is about 100 ppm. */ { unsigned long eax=0, edx=1000000; __asm__("divl %2" :"=a" (cpu_hz), "=d" (edx) :"r" (fast_gettimeoffset_quotient), "0" (eax), "1" (edx)); printk("Detected %ld Hz processor.\n", cpu_hz); } } setup_x86_irq(0, &irq0); } --Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd Content-Type: text/plain; name="mycpu1b.txt" Content-Transfer-Encoding: 8bit Content-Description: /proc/cpuinfo with a new look Content-Disposition: attachment; filename="mycpu1b.txt" processor : 0 cpu : 686 model : M II @ 233.86MHz +/- 0.01MHz vendor_id : CyrixInstead stepping : 2.8, core/bus clock ratio: 3.5x fdiv_bug : no hlt_bug : no f00f_bug : no fpu : yes fpu_exception : yes cpuid : yes wp : yes flags : fpu de tsc msr cx8 pge cmov mmx bogomips : 233.47 --Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd Content-Type: text/plain; name="test_time.txt" Content-Transfer-Encoding: 8bit Content-Description: result of Philip's time test code Content-Disposition: attachment; filename="test_time.txt" user->900362911.587306500, sys->900362911.587311, diff=4500 nsecs, cps=0 user->900362911.691335500, sys->900362911.691339, diff=3500 nsecs, cps=0 user->900362911.801316500, sys->900362911.801319, diff=2500 nsecs, cps=0 user->900362911.911326500, sys->900362911.911328, diff=1500 nsecs, cps=0 user->900362912.021315500, sys->900362912.021318, diff=2500 nsecs, cps=0 user->900362912.131381500, sys->900362912.131384, diff=2500 nsecs, cps=0 user->900362912.241317500, sys->900362912.241319, diff=1500 nsecs, cps=0 user->900362912.351328500, sys->900362912.351331, diff=2500 nsecs, cps=0 user->900362912.461314500, sys->900362912.461317, diff=2500 nsecs, cps=0 user->900362912.571326500, sys->900362912.571328, diff=1500 nsecs, cps=0 user->900362912.681368500, sys->900362912.681371, diff=2500 nsecs, cps=0 user->900362912.791330500, sys->900362912.791332, diff=1500 nsecs, cps=0 user->900362912.901317500, sys->900362912.901320, diff=2500 nsecs, cps=0 user->900362913.011326500, sys->900362913.011328, diff=1500 nsecs, cps=0 user->900362913.121316500, sys->900362913.121319, diff=2500 nsecs, cps=0 user->900362913.231380500, sys->900362913.231382, diff=1500 nsecs, cps=0 user->900362913.341325500, sys->900362913.341329, diff=3500 nsecs, cps=0 user->900362913.451335500, sys->900362913.451338, diff=2500 nsecs, cps=0 user->900362913.561317500, sys->900362913.561320, diff=2500 nsecs, cps=0 user->900362913.671325500, sys->900362913.671328, diff=2500 nsecs, cps=0 user->900362913.781381500, sys->900362913.781384, diff=2500 nsecs, cps=0 user->900362913.891424500, sys->900362913.891427, diff=2500 nsecs, cps=0 user->900362914.001318500, sys->900362914.001321, diff=2500 nsecs, cps=0 user->900362914.111328500, sys->900362914.111331, diff=2500 nsecs, cps=0 user->900362914.221315500, sys->900362914.221317, diff=1500 nsecs, cps=0 user->900362914.331379500, sys->900362914.331382, diff=2500 nsecs, cps=0 user->900362914.441316500, sys->900362914.441319, diff=2500 nsecs, cps=0 user->900362914.551332500, sys->900362914.551335, diff=2500 nsecs, cps=0 user->900362914.661315500, sys->900362914.661317, diff=1500 nsecs, cps=0 user->900362914.771325500, sys->900362914.771328, diff=2500 nsecs, cps=0 user->900362914.881372500, sys->900362914.881375, diff=2500 nsecs, cps=0 user->900362914.991331500, sys->900362914.991333, diff=1500 nsecs, cps=0 user->900362915.101316500, sys->900362915.101319, diff=2500 nsecs, cps=0 user->900362915.211325500, sys->900362915.211327, diff=1500 nsecs, cps=0 user->900362915.321314500, sys->900362915.321317, diff=2500 nsecs, cps=0 user->900362915.431379500, sys->900362915.431382, diff=2500 nsecs, cps=0 user->900362915.541400500, sys->900362915.541404, diff=3500 nsecs, cps=0 user->900362915.651328500, sys->900362915.651331, diff=2500 nsecs, cps=0 user->900362915.761315500, sys->900362915.761318, diff=2500 nsecs, cps=0 user->900362915.871327500, sys->900362915.871330, diff=2500 nsecs, cps=0 user->900362915.981369500, sys->900362915.981372, diff=2500 nsecs, cps=0 user->900362916.091329500, sys->900362916.091332, diff=2500 nsecs, cps=0 user->900362916.201314500, sys->900362916.201317, diff=2500 nsecs, cps=0 user->900362916.311325500, sys->900362916.311328, diff=2500 nsecs, cps=0 user->900362916.421317500, sys->900362916.421321, diff=3500 nsecs, cps=0 user->900362916.531379500, sys->900362916.531382, diff=2500 nsecs, cps=0 user->900362916.641317500, sys->900362916.641320, diff=2500 nsecs, cps=0 user->900362916.751328500, sys->900362916.751331, diff=2500 nsecs, cps=233867292 user->900362916.861315380, sys->900362916.861318, diff=2620 nsecs, cps=233867292 user->900362916.971324880, sys->900362916.971326, diff=1120 nsecs, cps=233867292 user->900362917.081374850, sys->900362917.081376, diff=1150 nsecs, cps=233867292 user->900362917.191327500, sys->900362917.191328, diff=500 nsecs, cps=233867292 user->900362917.301313690, sys->900362917.301315, diff=1310 nsecs, cps=233867292 user->900362917.411324060, sys->900362917.411325, diff=940 nsecs, cps=233867292 user->900362917.521316900, sys->900362917.521319, diff=2100 nsecs, cps=233867292 user->900362917.631379740, sys->900362917.631382, diff=2260 nsecs, cps=233867292 user->900362917.741315510, sys->900362917.741318, diff=2490 nsecs, cps=233867292 user->900362917.851331500, sys->900362917.851336, diff=4500 nsecs, cps=233867247 user->900362917.961319410, sys->900362917.961320, diff=590 nsecs, cps=233867247 user->900362918.071325760, sys->900362918.071326, diff=240 nsecs, cps=233867247 user->900362918.181368620, sys->900362918.181369, diff=380 nsecs, cps=233867247 user->900362918.291328280, sys->900362918.291328, diff=-280 nsecs, cps=233867247 user->900362918.401314700, sys->900362918.401315, diff=300 nsecs, cps=233867247 user->900362918.511325730, sys->900362918.511326, diff=270 nsecs, cps=233867247 user->900362918.621315970, sys->900362918.621316, diff=30 nsecs, cps=233867247 user->900362918.731379590, sys->900362918.731380, diff=410 nsecs, cps=233867247 user->900362918.841316750, sys->900362918.841318, diff=1250 nsecs, cps=233867247 user->900362918.951330500, sys->900362918.951333, diff=2500 nsecs, cps=233867257 user->900362919.061316370, sys->900362919.061317, diff=630 nsecs, cps=233867257 user->900362919.171324760, sys->900362919.171325, diff=240 nsecs, cps=233867257 user->900362919.281367880, sys->900362919.281368, diff=120 nsecs, cps=233867257 user->900362919.391328770, sys->900362919.391330, diff=1230 nsecs, cps=233867257 user->900362919.501317110, sys->900362919.501319, diff=1890 nsecs, cps=233867257 user->900362919.611325770, sys->900362919.611327, diff=1230 nsecs, cps=233867257 user->900362919.721314010, sys->900362919.721315, diff=990 nsecs, cps=233867257 user->900362919.831442500, sys->900362919.831444, diff=1500 nsecs, cps=233867257 user->900362919.941315480, sys->900362919.941317, diff=1520 nsecs, cps=233867257 user->900362920.051333500, sys->900362920.051337, diff=3500 nsecs, cps=233867244 user->900362920.161314310, sys->900362920.161315, diff=690 nsecs, cps=233867244 user->900362920.271325220, sys->900362920.271326, diff=780 nsecs, cps=233867244 user->900362920.381368640, sys->900362920.381369, diff=360 nsecs, cps=233867244 user->900362920.491328470, sys->900362920.491330, diff=1530 nsecs, cps=233867244 user->900362920.601315490, sys->900362920.601316, diff=510 nsecs, cps=233867244 user->900362920.711324720, sys->900362920.711325, diff=280 nsecs, cps=233867244 user->900362920.821315490, sys->900362920.821317, diff=1510 nsecs, cps=233867244 user->900362920.931381710, sys->900362920.931383, diff=1290 nsecs, cps=233867244 user->900362921.041397330, sys->900362921.041398, diff=670 nsecs, cps=233867244 user->900362921.151328500, sys->900362921.151331, diff=2500 nsecs, cps=233867241 user->900362921.261315060, sys->900362921.261315, diff=-60 nsecs, cps=233867241 user->900362921.371517590, sys->900362921.371519, diff=1410 nsecs, cps=233867241 user->900362921.481417750, sys->900362921.481421, diff=3250 nsecs, cps=233867241 user->900362921.591328820, sys->900362921.591330, diff=1180 nsecs, cps=233867241 user->900362921.701314220, sys->900362921.701315, diff=780 nsecs, cps=233867241 user->900362921.811325540, sys->900362921.811326, diff=460 nsecs, cps=233867241 user->900362921.921315590, sys->900362921.921316, diff=410 nsecs, cps=233867241 user->900362922.031379110, sys->900362922.031380, diff=890 nsecs, cps=233867241 user->900362922.141315640, sys->900362922.141317, diff=1360 nsecs, cps=233867241 user->900362922.251328500, sys->900362922.251333, diff=4500 nsecs, cps=233867247 user->900362922.361314710, sys->900362922.361315, diff=290 nsecs, cps=233867247 user->900362922.471324770, sys->900362922.471326, diff=1230 nsecs, cps=233867247 Cached quotient = 627254613, our quotient = 1836497992 Difference amounts to 43ns per second .................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................. k after u: 900362941.261318999 before 900362941.261319050 (50 nsecs) k after u: 900362941.261354999 before 900362941.261355110 (110 nsecs) k after u: 900362941.261390999 before 900362941.261391170 (170 nsecs). k after u: 900362941.281413999 before 900362941.281414200 (200 nsecs) k after u: 900362941.281644999 before 900362941.281645210 (210 nsecs) k after u: 900362941.281680999 before 900362941.281681230 (230 nsecs) k after u: 900362941.282035999 before 900362941.282036240 (240 nsecs). k after u: 900362941.321705999 before 900362941.321706250 (250 nsecs) k after u: 900362941.321752999 before 900362941.321753270 (270 nsecs) k after u: 900362941.321782999 before 900362941.321783290 (290 nsecs). k after u: 900362941.361327999 before 900362941.361328300 (300 nsecs) k after u: 900362941.361545999 before 900362941.361546310 (310 nsecs) k after u: 900362941.361603999 before 900362941.361604320 (320 nsecs).. k after u: 900362941.421416999 before 900362941.421417330 (330 nsecs)..... k after u: 900362941.561335999 before 900362941.561336400 (400 nsecs)................... k after u: 900362942.161420999 before 900362942.161421410 (410 nsecs).......................................................................................................................................................................................................................................................................................................................................................................................... The largest error was 410nsecs (which seems OK) Cycle limit for system gettimeofday = 648 final cq=627254613 --Boundary-=_XrJmOWFrxsjyBldbEFSArCBynEcd-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.altern.org/andrebalsa/doc/lkml-faq.html