On Mon, Aug 28, 2017 at 08:02:35AM +0800, Adam Steen wrote:
> On Fri, Aug 25, 2017 at 12:43:44PM +0200, Mike Belopuhov wrote:
> > On Fri, Aug 25, 2017 at 00:40 -0700, Mike Larkin wrote:
> > > On Thu, Aug 24, 2017 at 12:39:33PM +0800, Adam Steen wrote:
> > > > On Thu, Aug 24, 2017 at 2:35 AM, Mike Larkin <mlar...@azathoth.net>
> > > > wrote:
> > > > > On Wed, Aug 23, 2017 at 09:29:15PM +0800, Adam Steen wrote:
> > > > >>
> > > > >> Thank you Mike on the feedback on the last patch, please see the diff
> > > > >> below, update with your input and style(9)
> > > > >>
> > > > >> I have continued to use tsc as my timecounter and /var/db/ntpd.driff
> > > > >> has stayed under 10.
> > > > >>
> > > > >> cat /var/db/ntpd.drift
> > > > >> 6.665
> > > > >>
> > > > >> ntpctl -s all
> > > > >> 4/4 peers valid, constraint offset -1s, clock synced, stratum 3
> > > > >>
> > > > >> peer
> > > > >> wt tl st next poll offset delay jitter
> > > > >> 144.48.166.166 from pool pool.ntp.org
> > > > >> 1 10 2 4s 32s -3.159ms 87.723ms 10.389ms
> > > > >> 13.55.50.68 from pool pool.ntp.org
> > > > >> 1 10 3 11s 32s -3.433ms 86.053ms 18.095ms
> > > > >> 14.202.204.182 from pool pool.ntp.org
> > > > >> 1 10 1 14s 32s 1.486ms 86.545ms 16.483ms
> > > > >> 27.124.125.250 from pool pool.ntp.org
> > > > >> * 1 10 2 12s 30s -10.275ms 54.156ms 70.389ms
> > > > >>
> > > > >> Cheers
> > > > >> Adam
> > > > >
> > > > > IIRC you have an x220, right?
> > > > >
> > > > > If so, could you try letting the clock run for a bit (while using tsc
> > > > > timecounter selection) after apm -L to drop the speed? (make sure
> > > > > apm shows that it dropped).
> > > > >
> > > > > Even though my x230 supposedly has a constant/invar TSC (according to
> > > > > cpuid), the TSC drops from 2.5GHz to 1.2GHz when apm -L runs, which
> > > > > causes time to run too slowly when tsc is selected there.
> > > > >
> > > > > -ml
> > > > >
> > > >
> > > > Yes, x220
> > > > (bios: LENOVO version "8DET69WW (1.39 )" date 07/18/2013)
> > > > (cpu: Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, 2491.91 MHz)
> > > >
> > > > I took some measurements to before starting the test.
> > > >
> > > > note: the laptop has been up for a few days with apm -A set via
> > > > rc.conf.local
> > > > and sysctl kern.timecounter.hardware as tsc via sysctl.conf and mostly
> > > > idle.
> > > >
> > > > cat /var/db/ntpd.drift
> > > > 6.459
> > > >
> > > > apm -v
> > > > Battery state: high, 100% remaining, unknown life estimate
> > > > A/C adapter state: connected
> > > > Performance adjustment mode: auto (800 MHz)
> > > >
> > > > 6 hours ago i ran apm -L, verified it was running slowly (800 MHz),
> > > > and got the following results
> > > >
> > > > The clock appears correct (comparing to other computers)
> > > >
> > > > apm -v
> > > > Battery state: high, 100% remaining, unknown life estimate
> > > > A/C adapter state: connected
> > > > Performance adjustment mode: manual (800 MHz)
> > > >
> > > > cat /var/db/ntpd.drift
> > > > 6.385
> > > >
> > > > ntpctl -s all
> > > > 4/4 peers valid, constraint offset 0s, clock synced, stratum 4
> > > >
> > > > peer
> > > > wt tl st next poll offset delay jitter
> > > > 203.23.237.200 from pool pool.ntp.org
> > > > 1 10 2 153s 1505s -25.546ms 73.450ms 2.644ms
> > > > 203.114.73.24 from pool pool.ntp.org
> > > > 1 10 2 253s 1560s -1.042ms 75.133ms 0.752ms
> > > > 192.189.54.33 from pool pool.ntp.org
> > > > * 1 10 2 204s 1558s 31.644ms 70.910ms 3.388ms
> > > > 54.252.165.245 from pool pool.ntp.org
> > > > 1 10 2 238s 1518s 0.146ms 73.005ms 2.025ms
> > > >
> > > > I will leave the laptop in lower power mode over the weekend and see
> > > > what happens.
> > > >
> > >
> > > No need, I think you've convinced me that it works :)
> >
> > But does it actually work on x230 as well? I'm surprised to learn
> > that you've observed TSC frequency change on Ivy Bridge. I was
> > under impression that everything since at least Sandy Bridge (x220)
> > has constant and invariant TSC as advertised.
> >
> > Adam, I've readjusted and simplified your diff a bit. The biggest
> > change is that we can select the reference tc based on it's quality
> > so there's no need to have acpitimer and acpihpet specific functions
> > and variables.
> >
> > There's one big thing missing here: increasing the timecounter
> > quality so that OS can pick it. Something like this:
> >
> > https://github.com/mbelop/src/commit/99d6ef3ae95bbd8ea93c27e0425eb65e5a3359a1
> >
> > I'd say we should try getting this in after 6.3 unlock unless there
> > are objections. Further cleanup and testing is welcome of course.
> >
>
> Hi all
>
> I wanted to post the complicated patch, along with Mike's qaulity
> changes for completeness sake, see the diff below.
>
> I have been running this since Saturday morning with no
> problems.
>
> Cheers
> Adam
>
This diff works fine on the x230. And although there is no hpet inside
vmm/vmd, if you pick tsc anyway, it seems to have less time drift than
the 8254/PIT. So, that's good. It's not perfect but it's better.
mikeb, do you want to get this in? the diff reads ok to me.
-ml
> Index: sys/arch/amd64/amd64/acpi_machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/amd64/acpi_machdep.c,v
> retrieving revision 1.78
> diff -u -p -u -p -r1.78 acpi_machdep.c
> --- sys/arch/amd64/amd64/acpi_machdep.c 27 Mar 2017 18:32:53 -0000
> 1.78
> +++ sys/arch/amd64/amd64/acpi_machdep.c 27 Aug 2017 23:33:22 -0000
> @@ -69,6 +69,15 @@ extern int acpi_savecpu(void) __returns_
>
> u_int8_t *acpi_scan(struct acpi_mem_map *, paddr_t, size_t);
>
> +#define RECALIBRATE_MAX_RETRIES 5
> +#define RECALIBRATE_SMI_THRESHOLD 50000
> +#define RECALIBRATE_DELAY_THRESHOLD 20
> +
> +struct timecounter *recalibrate_tc;
> +
> +uint64_t acpi_calibrate_tsc_freq(void);
> +int acpi_get_tsc_and_timecount(struct timecounter *, uint64_t *, uint64_t *);
> +
> int
> acpi_map(paddr_t pa, size_t len, struct acpi_mem_map *handle)
> {
> @@ -438,6 +447,108 @@ acpi_resume_cpu(struct acpi_softc *sc)
> /* Re-initialise memory range handling on BSP */
> if (mem_range_softc.mr_op != NULL)
> mem_range_softc.mr_op->initAP(&mem_range_softc);
> +}
> +
> +int
> +acpi_get_tsc_and_timecount(struct timecounter *tc, uint64_t *tsc,
> + uint64_t *count)
> +{
> + uint64_t n, tsc1, tsc2;
> + int i;
> +
> + for (i = 0; i < RECALIBRATE_MAX_RETRIES; i++) {
> + tsc1 = rdtsc();
> + n = (tc->tc_get_timecount(tc) & tc->tc_counter_mask);
> + tsc2 = rdtsc();
> +
> + if ((tsc2 - tsc1) < RECALIBRATE_SMI_THRESHOLD) {
> + *count = n;
> + *tsc = tsc2;
> + return (0);
> + }
> + }
> + return 1;
> +}
> +
> +void
> +acpi_recalibrate_tsc(struct timecounter *tc)
> +{
> + if (!recalibrate_tc ||
> + recalibrate_tc->tc_quality < tc->tc_quality) {
> + recalibrate_tc = tc;
> + cpu_adjust_tsc_freq(&acpi_calibrate_tsc_freq);
> + }
> +}
> +
> +static inline uint64_t
> +acpi_calculate_tsc_freq(uint64_t tsc1, uint64_t tsc2, int usec)
> +{
> + uint64_t delta;
> +
> + delta = (tsc2 - tsc1);
> + return delta * 1000000 / usec;
> +}
> +
> +static inline uint64_t
> +acpi_calculate_tc_delay(struct timecounter *tc, uint64_t count1,
> + uint64_t count2)
> +{
> + uint64_t delta;
> +
> + if (count2 < count1)
> + count2 += tc->tc_counter_mask;
> +
> + delta = (count2 - count1);
> + return delta * 1000000 / tc->tc_frequency;
> +}
> +
> +uint64_t
> +acpi_calibrate_tsc_freq(void)
> +{
> + struct timecounter *tc;
> + uint64_t count1, count2, frequency, min_freq, tsc1, tsc2;
> + u_long ef;
> + int delay_usec, i, err1, err2, usec;
> +
> + if (recalibrate_tc == NULL)
> + return 0;
> +
> + tc = recalibrate_tc;
> +
> + /* warmup the timers */
> + for (i =0; i < 3; i++) {
> + (void)tc->tc_get_timecount(tc);
> + (void)rdtsc();
> + }
> +
> + min_freq = ULLONG_MAX;
> +
> + delay_usec = 100000;
> + for (i = 0; i < 3; i++) {
> + ef = read_rflags();
> + disable_intr();
> +
> + err1 = acpi_get_tsc_and_timecount(tc, &tsc1, &count1);
> + delay(delay_usec);
> + err2 = acpi_get_tsc_and_timecount(tc, &tsc2, &count2);
> +
> + write_rflags(ef);
> +
> + if (err1 || err2)
> + continue;
> +
> + usec = acpi_calculate_tc_delay(tc, count1, count2);
> +
> + if ((usec < (delay_usec - RECALIBRATE_DELAY_THRESHOLD)) ||
> + (usec > (delay_usec + RECALIBRATE_DELAY_THRESHOLD)))
> + continue;
> +
> + frequency = acpi_calculate_tsc_freq(tsc1, tsc2, usec);
> +
> + min_freq = ulmin(min_freq, frequency);
> + }
> +
> + return min_freq;
> }
>
> #ifdef MULTIPROCESSOR
> Index: sys/arch/amd64/amd64/identcpu.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/amd64/identcpu.c,v
> retrieving revision 1.87
> diff -u -p -u -p -r1.87 identcpu.c
> --- sys/arch/amd64/amd64/identcpu.c 20 Jun 2017 05:34:41 -0000 1.87
> +++ sys/arch/amd64/amd64/identcpu.c 27 Aug 2017 23:33:22 -0000
> @@ -63,6 +63,11 @@ struct timecounter tsc_timecounter = {
> tsc_get_timecount, NULL, ~0u, 0, "tsc", -1000, NULL
> };
>
> +u_int64_t amd64_tsc_freq;
> +int amd64_tsc_recalibrate;
> +u_int64_t (*amd64_tsc_get_freq)();
> +
> +int amd64_has_invariant_tsc;
> int amd64_has_xcrypt;
> #ifdef CRYPTO
> int amd64_has_pclmul;
> @@ -428,8 +433,9 @@ cpu_tsc_freq_ctr(struct cpu_info *ci)
> u_int64_t
> cpu_tsc_freq(struct cpu_info *ci)
> {
> - u_int64_t last_count, count;
> + u_int64_t last_count, count, sum;
> uint32_t eax, ebx, khz, dummy;
> + int i;
>
> if (!strcmp(cpu_vendor, "GenuineIntel") &&
> cpuid_level >= 0x15) {
> @@ -468,11 +474,25 @@ cpu_tsc_freq(struct cpu_info *ci)
> if (count != 0)
> return (count);
>
> - last_count = rdtsc();
> - delay(100000);
> - count = rdtsc();
> + if (amd64_tsc_get_freq != NULL &&
> + (count = (*amd64_tsc_get_freq)()) != 0) {
> + if (amd64_has_invariant_tsc)
> + tsc_timecounter.tc_quality = 2000;
> + return (count);
> + }
>
> - return ((count - last_count) * 10);
> + if (ci->ci_flags & CPUF_PRIMARY)
> + amd64_tsc_recalibrate = 1;
> +
> + sum = 0;
> + for (i=0; i < 8; i++) {
> + last_count = rdtsc();
> + delay(100000);
> + count = rdtsc();
> + sum += (count - last_count);
> + }
> +
> + return ((sum >> 3) * 10);
> }
>
> u_int
> @@ -482,6 +502,26 @@ tsc_get_timecount(struct timecounter *tc
> }
>
> void
> +cpu_adjust_tsc_freq(u_int64_t (*get_frequency)())
> +{
> + u_int64_t freq;
> +
> + if (amd64_tsc_recalibrate) {
> + if ((freq = (*get_frequency)()) == 0)
> + return;
> + amd64_tsc_freq = freq;
> + tsc_timecounter.tc_frequency = freq;
> + if (amd64_has_invariant_tsc)
> + tsc_timecounter.tc_quality = 2000;
> +
> + printf("%s: updated TSC frequency %lld\n",
> + curcpu()->ci_dev->dv_xname,
> + tsc_timecounter.tc_frequency);
> + } else
> + amd64_tsc_get_freq = get_frequency;
> +}
> +
> +void
> identifycpu(struct cpu_info *ci)
> {
> u_int32_t dummy, val;
> @@ -566,9 +606,13 @@ identifycpu(struct cpu_info *ci)
> /* Check if it's an invariant TSC */
> if (cpu_apmi_edx & CPUIDEDX_ITSC)
> ci->ci_flags |= CPUF_INVAR_TSC;
> +
> + amd64_has_invariant_tsc = (ci->ci_flags & CPUF_INVAR_TSC) != 0;
> }
>
> ci->ci_tsc_freq = cpu_tsc_freq(ci);
> + if (ci->ci_flags & CPUF_PRIMARY)
> + amd64_tsc_freq = ci->ci_tsc_freq;
>
> amd_cpu_cacheinfo(ci);
>
> Index: sys/arch/amd64/amd64/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/amd64/machdep.c,v
> retrieving revision 1.231
> diff -u -p -u -p -r1.231 machdep.c
> --- sys/arch/amd64/amd64/machdep.c 12 Jul 2017 06:26:32 -0000 1.231
> +++ sys/arch/amd64/amd64/machdep.c 27 Aug 2017 23:33:22 -0000
> @@ -425,6 +425,8 @@ int
> cpu_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
> size_t newlen, struct proc *p)
> {
> + extern u_int64_t amd64_tsc_freq;
> + extern int amd64_has_invariant_tsc;
> extern int amd64_has_xcrypt;
> dev_t consdev;
> dev_t dev;
> @@ -496,6 +498,11 @@ cpu_sysctl(int *name, u_int namelen, voi
> pckbc_release_console();
> return (error);
> #endif
> + case CPU_TSCFREQ:
> + return (sysctl_rdquad(oldp, oldlenp, newp, amd64_tsc_freq));
> + case CPU_INVARIANTTSC:
> + return (sysctl_rdint(oldp, oldlenp, newp,
> + amd64_has_invariant_tsc));
> default:
> return (EOPNOTSUPP);
> }
> Index: sys/arch/amd64/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v
> retrieving revision 1.114
> diff -u -p -u -p -r1.114 cpu.h
> --- sys/arch/amd64/include/cpu.h 11 Aug 2017 20:19:14 -0000 1.114
> +++ sys/arch/amd64/include/cpu.h 27 Aug 2017 23:33:24 -0000
> @@ -427,7 +427,9 @@ void mp_setperf_init(void);
> #define CPU_XCRYPT 12 /* supports VIA xcrypt in userland */
> #define CPU_LIDACTION 14 /* action caused by lid close */
> #define CPU_FORCEUKBD 15 /* Force ukbd(4) as console
> keyboard */
> -#define CPU_MAXID 16 /* number of valid machdep ids */
> +#define CPU_TSCFREQ 16 /* tsc frequency */
> +#define CPU_INVARIANTTSC 17 /* has invariant tsc */
> +#define CPU_MAXID 18 /* number of valid machdep ids */
>
> #define CTL_MACHDEP_NAMES { \
> { 0, 0 }, \
> @@ -446,6 +448,8 @@ void mp_setperf_init(void);
> { 0, 0 }, \
> { "lidaction", CTLTYPE_INT }, \
> { "forceukbd", CTLTYPE_INT }, \
> + { "tscfreq", CTLTYPE_QUAD }, \
> + { "invarianttsc", CTLTYPE_INT }, \
> }
>
> /*
> Index: sys/arch/amd64/include/cpuvar.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/include/cpuvar.h,v
> retrieving revision 1.8
> diff -u -p -u -p -r1.8 cpuvar.h
> --- sys/arch/amd64/include/cpuvar.h 28 Jul 2016 21:57:57 -0000 1.8
> +++ sys/arch/amd64/include/cpuvar.h 27 Aug 2017 23:33:24 -0000
> @@ -96,5 +96,6 @@ void x86_ipi_init(int);
> void identifycpu(struct cpu_info *);
> void cpu_init(struct cpu_info *);
> void cpu_init_first(void);
> +void cpu_adjust_tsc_freq(uint64_t (*)());
>
> #endif
> Index: sys/dev/acpi/acpihpet.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/acpi/acpihpet.c,v
> retrieving revision 1.21
> diff -u -p -u -p -r1.21 acpihpet.c
> --- sys/dev/acpi/acpihpet.c 6 Oct 2015 20:49:32 -0000 1.21
> +++ sys/dev/acpi/acpihpet.c 27 Aug 2017 23:33:26 -0000
> @@ -264,6 +264,7 @@ acpihpet_attach(struct device *parent, s
> hpet_timecounter.tc_priv = sc;
> hpet_timecounter.tc_name = sc->sc_dev.dv_xname;
> tc_init(&hpet_timecounter);
> + acpi_recalibrate_tsc(&hpet_timecounter);
> acpihpet_attached++;
> }
>
> Index: sys/dev/acpi/acpitimer.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/acpi/acpitimer.c,v
> retrieving revision 1.11
> diff -u -p -u -p -r1.11 acpitimer.c
> --- sys/dev/acpi/acpitimer.c 14 Mar 2015 03:38:46 -0000 1.11
> +++ sys/dev/acpi/acpitimer.c 27 Aug 2017 23:33:26 -0000
> @@ -95,6 +95,7 @@ acpitimerattach(struct device *parent, s
> acpi_timecounter.tc_counter_mask = 0xffffffffU;
> acpi_timecounter.tc_priv = sc;
> acpi_timecounter.tc_name = sc->sc_dev.dv_xname;
> + acpi_recalibrate_tsc(&acpi_timecounter);
> tc_init(&acpi_timecounter);
> }
>
> Index: sys/dev/acpi/acpivar.h
> ===================================================================
> RCS file: /cvs/src/sys/dev/acpi/acpivar.h,v
> retrieving revision 1.88
> diff -u -p -u -p -r1.88 acpivar.h
> --- sys/dev/acpi/acpivar.h 17 Aug 2017 05:16:27 -0000 1.88
> +++ sys/dev/acpi/acpivar.h 27 Aug 2017 23:33:26 -0000
> @@ -25,6 +25,7 @@
>
> #include <sys/timeout.h>
> #include <sys/rwlock.h>
> +#include <sys/timetc.h>
> #include <machine/biosvar.h>
>
> #include "acpipwrres.h"
> @@ -324,6 +325,8 @@ void acpi_resume_cpu(struct acpi_softc
> void acpi_resume_mp(void);
> void acpi_sleep_walk(struct acpi_softc *, int);
>
> +void acpi_recalibrate_tsc(struct timecounter *);
> +uint64_t acpi_calibrate_tsc_freq();
>
> #define ACPI_IOREAD 0
> #define ACPI_IOWRITE 1
>
