Date: Fri, 01 Aug 2014 20:48:43 +0200 From: =?ISO-8859-1?Q?Jan_Kokem=FCller?= <jan.kokemueller@gmail.com> To: freebsd-current@freebsd.org Subject: Re: Fresh current (r269328) amd64: high load average while idle, slow keyboard reaction Message-ID: <53DBE10B.9010202@gmail.com> In-Reply-To: <53DA6727.7080702@gmail.com> References: <20140731142100.GP92036@heechee.tobez.org> <53DA6727.7080702@gmail.com>
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Hi,
> Maybe this is a problem caused by a misdetected clock source? I've had
> this problem as well.
I've appended the patch I've been using to fix this problem on this
Intel Core2Duo T6570 processor. There are some model IDs hardcoded in
the TSC detection code that enable TSC even though it's not invariant
here (no TSC_INVARIANT bit set on the CPU). There is some quirk code
further down that disables TSC once again, but it only works for
processors that have C3 power states (the T6570 doesn't). I don't think
any of this model checking code is necessary, but maybe I'm wrong.
Cheers,
Jan
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name="fix-invariant-tsc-detection.patch"
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filename="fix-invariant-tsc-detection.patch"
diff --git a/sys/x86/x86/tsc.c b/sys/x86/x86/tsc.c
index 2a6c81d..a30424e 100644
--- a/sys/x86/x86/tsc.c
+++ b/sys/x86/x86/tsc.c
@@ -57,7 +57,8 @@ int tsc_perf_stat;
static eventhandler_tag tsc_levels_tag, tsc_pre_tag, tsc_post_tag;
SYSCTL_INT(_kern_timecounter, OID_AUTO, invariant_tsc, CTLFLAG_RDTUN,
- &tsc_is_invariant, 0, "Indicates whether the TSC is P-state invariant");
+ &tsc_is_invariant, 0,
+ "Indicates whether the TSC is ACPI P-, C- and T-state invariant");
TUNABLE_INT("kern.timecounter.invariant_tsc", &tsc_is_invariant);
#ifdef SMP
@@ -272,9 +273,7 @@ probe_tsc_freq(void)
switch (cpu_vendor_id) {
case CPU_VENDOR_AMD:
- if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 ||
- (vm_guest == VM_GUEST_NO &&
- CPUID_TO_FAMILY(cpu_id) >= 0x10))
+ if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0)
tsc_is_invariant = 1;
if (cpu_feature & CPUID_SSE2) {
tsc_timecounter.tc_get_timecount =
@@ -282,12 +281,7 @@ probe_tsc_freq(void)
}
break;
case CPU_VENDOR_INTEL:
- if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 ||
- (vm_guest == VM_GUEST_NO &&
- ((CPUID_TO_FAMILY(cpu_id) == 0x6 &&
- CPUID_TO_MODEL(cpu_id) >= 0xe) ||
- (CPUID_TO_FAMILY(cpu_id) == 0xf &&
- CPUID_TO_MODEL(cpu_id) >= 0x3))))
+ if ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0)
tsc_is_invariant = 1;
if (cpu_feature & CPUID_SSE2) {
tsc_timecounter.tc_get_timecount =
@@ -554,20 +548,6 @@ init_TSC_tc(void)
}
/*
- * We cannot use the TSC if it stops incrementing in deep sleep.
- * Currently only Intel CPUs are known for this problem unless
- * the invariant TSC bit is set.
- */
- if (cpu_can_deep_sleep && cpu_vendor_id == CPU_VENDOR_INTEL &&
- (amd_pminfo & AMDPM_TSC_INVARIANT) == 0) {
- tsc_timecounter.tc_quality = -1000;
- tsc_timecounter.tc_flags |= TC_FLAGS_C3STOP;
- if (bootverbose)
- printf("TSC timecounter disabled: C3 enabled.\n");
- goto init;
- }
-
- /*
* We can not use the TSC in SMP mode unless the TSCs on all CPUs
* are synchronized. If the user is sure that the system has
* synchronized TSCs, set kern.timecounter.smp_tsc tunable to a
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