Just passing a string to mark_tsc_unstable() doesn't allow real code to change based on the reason for the instablility. I changed mark_tsc_unstable() to accept a string and a flag which denotes a general reason why the tsc is unstable, and can be evaluated in code. This is based off John Stultz patch to add the string reasons. Signed-Off-By: Daniel Walker --- arch/i386/kernel/cpu/cyrix.c | 9 ++++-- arch/i386/kernel/tsc.c | 39 +++++++++++++++++----------- arch/x86_64/kernel/time.c | 3 +- arch/x86_64/kernel/tsc.c | 28 +++++++++++++------- arch/x86_64/kernel/tsc_sync.c | 3 +- drivers/acpi/processor_idle.c | 6 ++-- include/asm-i386/mach-summit/mach_mpparse.h | 5 ++- include/asm-i386/tsc.h | 13 ++++++++- include/asm-x86_64/timex.h | 1 9 files changed, 73 insertions(+), 34 deletions(-) Index: linux-2.6.21/arch/i386/kernel/cpu/cyrix.c =================================================================== --- linux-2.6.21.orig/arch/i386/kernel/cpu/cyrix.c +++ linux-2.6.21/arch/i386/kernel/cpu/cyrix.c @@ -275,11 +275,14 @@ static void __cpuinit init_cyrix(struct device = read_pci_config_16(0, 0, 0x12, PCI_DEVICE_ID); /* - * The 5510/5520 companion chips have a funky PIT. + * The 5510/5520 companion chips have a funky PIT + * and an unstable TSC. */ if (vendor == PCI_VENDOR_ID_CYRIX && - (device == PCI_DEVICE_ID_CYRIX_5510 || device == PCI_DEVICE_ID_CYRIX_5520)) - pit_latch_buggy = 1; + (device == PCI_DEVICE_ID_CYRIX_5510 || + device == PCI_DEVICE_ID_CYRIX_5520)) + mark_tsc_unstable(CLOCK_TSC_UNSTABLE_FREQUENCY, + "cyrix 5510/5520 detected"); } #endif c->x86_cache_size=16; /* Yep 16K integrated cache thats it */ Index: linux-2.6.21/arch/i386/kernel/tsc.c =================================================================== --- linux-2.6.21.orig/arch/i386/kernel/tsc.c +++ linux-2.6.21/arch/i386/kernel/tsc.c @@ -233,7 +233,8 @@ time_cpufreq_notifier(struct notifier_bl * TSC based sched_clock turns * to junk w/ cpufreq */ - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_CPUFREQ_ADJUSTED, + "cpufreq changes"); } } } @@ -281,25 +282,34 @@ static struct clocksource clocksource_ts CLOCK_SOURCE_MUST_VERIFY, }; -void mark_tsc_unstable(void) +void mark_tsc_unstable(enum tsc_unstable_flags flag, char *reason) { - if (!tsc_unstable) { - tsc_unstable = 1; - tsc_enabled = 0; - /* Can be called before registration */ - if (clocksource_tsc.mult) - clocksource_change_rating(&clocksource_tsc, 0); - else - clocksource_tsc.rating = 0; + if (likely(tsc_unstable)) + return; + + switch (flag) { + case CLOCK_TSC_UNSTABLE_FREQUENCY: + case CLOCK_TSC_HALTS_IN_CSTATES: + + case CLOCK_TSC_UNSYNCHRONIZED: + case CLOCK_TSC_CPUFREQ_ADJUSTED: + tsc_unstable = 1; + tsc_enabled = 0; + printk("Marking TSC unstable due to: %s.\n", reason); + /* Can be called before registration */ + if (clocksource_tsc.mult) + clocksource_change_rating(&clocksource_tsc, 0); + else + clocksource_tsc.rating = 0; } } EXPORT_SYMBOL_GPL(mark_tsc_unstable); static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d) { - printk(KERN_NOTICE "%s detected: marking TSC unstable.\n", - d->ident); - tsc_unstable = 1; + + mark_tsc_unstable(CLOCK_TSC_UNSTABLE_FREQUENCY, (char*)d->ident); + return 0; } @@ -331,7 +341,8 @@ __cpuinit int unsynchronized_tsc(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) { /* assume multi socket systems are not synchronized: */ if (num_possible_cpus() > 1) - tsc_unstable = 1; + mark_tsc_unstable(CLOCK_TSC_UNSYNCHRONIZED, + "Non-Intel SMP system"); } return tsc_unstable; } Index: linux-2.6.21/arch/x86_64/kernel/time.c =================================================================== --- linux-2.6.21.orig/arch/x86_64/kernel/time.c +++ linux-2.6.21/arch/x86_64/kernel/time.c @@ -348,7 +348,8 @@ void __init time_init(void) } if (unsynchronized_tsc()) - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_UNSYNCHRONIZED, + "TSCs unsynchronized"); if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP)) vgetcpu_mode = VGETCPU_RDTSCP; Index: linux-2.6.21/arch/x86_64/kernel/tsc.c =================================================================== --- linux-2.6.21.orig/arch/x86_64/kernel/tsc.c +++ linux-2.6.21/arch/x86_64/kernel/tsc.c @@ -109,7 +109,8 @@ static int time_cpufreq_notifier(struct cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new); if (!(freq->flags & CPUFREQ_CONST_LOOPS)) - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_CPUFREQ_ADJUSTED, + "cpufreq changes"); } set_cyc2ns_scale(cpu_khz_ref); @@ -197,15 +198,24 @@ static struct clocksource clocksource_ts .vread = vread_tsc, }; -void mark_tsc_unstable(void) +void mark_tsc_unstable(enum tsc_unstable_flags flag, char *reason) { - if (!tsc_unstable) { - tsc_unstable = 1; - /* Change only the rating, when not registered */ - if (clocksource_tsc.mult) - clocksource_change_rating(&clocksource_tsc, 0); - else - clocksource_tsc.rating = 0; + if (likely(tsc_unstable)) + return; + + switch (flag) { + case CLOCK_TSC_UNSTABLE_FREQUENCY: + case CLOCK_TSC_HALTS_IN_CSTATES: + + case CLOCK_TSC_UNSYNCHRONIZED: + case CLOCK_TSC_CPUFREQ_ADJUSTED: + tsc_unstable = 1; + printk("Marking TSC unstable due to: %s.\n", reason); + /* Can be called before registration */ + if (clocksource_tsc.mult) + clocksource_change_rating(&clocksource_tsc, 0); + else + clocksource_tsc.rating = 0; } } EXPORT_SYMBOL_GPL(mark_tsc_unstable); Index: linux-2.6.21/arch/x86_64/kernel/tsc_sync.c =================================================================== --- linux-2.6.21.orig/arch/x86_64/kernel/tsc_sync.c +++ linux-2.6.21/arch/x86_64/kernel/tsc_sync.c @@ -138,7 +138,8 @@ void __cpuinit check_tsc_sync_source(int printk("\n"); printk(KERN_WARNING "Measured %Ld cycles TSC warp between CPUs," " turning off TSC clock.\n", max_warp); - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_UNSTABLE_FREQUENCY, + "check_tsc_sync_source failed"); nr_warps = 0; max_warp = 0; last_tsc = 0; Index: linux-2.6.21/drivers/acpi/processor_idle.c =================================================================== --- linux-2.6.21.orig/drivers/acpi/processor_idle.c +++ linux-2.6.21/drivers/acpi/processor_idle.c @@ -483,7 +483,8 @@ static void acpi_processor_idle(void) #ifdef CONFIG_GENERIC_TIME /* TSC halts in C2, so notify users */ - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_HALTS_IN_CSTATES, + "possible TSC halt in C2"); #endif /* Re-enable interrupts */ local_irq_enable(); @@ -525,7 +526,8 @@ static void acpi_processor_idle(void) #ifdef CONFIG_GENERIC_TIME /* TSC halts in C3, so notify users */ - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_HALTS_IN_CSTATES, + "TSC halts in C3"); #endif /* Re-enable interrupts */ local_irq_enable(); Index: linux-2.6.21/include/asm-i386/mach-summit/mach_mpparse.h =================================================================== --- linux-2.6.21.orig/include/asm-i386/mach-summit/mach_mpparse.h +++ linux-2.6.21/include/asm-i386/mach-summit/mach_mpparse.h @@ -30,7 +30,8 @@ static inline int mps_oem_check(struct m (!strncmp(productid, "VIGIL SMP", 9) || !strncmp(productid, "EXA", 3) || !strncmp(productid, "RUTHLESS SMP", 12))){ - mark_tsc_unstable(); + mark_tsc_unstable(CLOCK_TSC_UNSYNCHRONIZED, + "Summit based system"); use_cyclone = 1; /*enable cyclone-timer*/ setup_summit(); return 1; @@ -44,7 +45,7 @@ static inline int acpi_madt_oem_check(ch if (!strncmp(oem_id, "IBM", 3) && (!strncmp(oem_table_id, "SERVIGIL", 8) || !strncmp(oem_table_id, "EXA", 3))){ - mark_tsc_unstable(); + mark_tsc_unstable("Summit based system"); use_cyclone = 1; /*enable cyclone-timer*/ setup_summit(); return 1; Index: linux-2.6.21/include/asm-i386/tsc.h =================================================================== --- linux-2.6.21.orig/include/asm-i386/tsc.h +++ linux-2.6.21/include/asm-i386/tsc.h @@ -52,8 +52,19 @@ static __always_inline cycles_t get_cycl return ret; } +/* + * These are the known reason why a TSC would be flaged + * as unstable. + */ +enum tsc_unstable_flags { + CLOCK_TSC_UNSTABLE_FREQUENCY = 0, + CLOCK_TSC_CPUFREQ_ADJUSTED, + CLOCK_TSC_UNSYNCHRONIZED, + CLOCK_TSC_HALTS_IN_CSTATES, +}; +extern void mark_tsc_unstable(enum tsc_unstable_flags flag, char *reason); + extern void tsc_init(void); -extern void mark_tsc_unstable(void); extern int unsynchronized_tsc(void); extern void init_tsc_clocksource(void); Index: linux-2.6.21/include/asm-x86_64/timex.h =================================================================== --- linux-2.6.21.orig/include/asm-x86_64/timex.h +++ linux-2.6.21/include/asm-x86_64/timex.h @@ -27,6 +27,5 @@ extern int read_current_timer(unsigned l #define NS_SCALE 10 /* 2^10, carefully chosen */ #define US_SCALE 32 /* 2^32, arbitralrily chosen */ -extern void mark_tsc_unstable(void); extern void set_cyc2ns_scale(unsigned long khz); #endif -- - 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/