https://bugzilla.kernel.org/show_bug.cgi?id=12114 --- Comment #15 from Dominique Larchey-Wendling <larchey@xxxxxxxx> 2011-03-09 17:09:30 --- With CONFIG_X86_TSC disabled, using the TSC is still possible from userland via prctl : # gcc disable-tsc-test.c -o test # ./test rdtsc() == 1221707443605 prctl(PR_GET_TSC, &tsc_val); tsc_val == PR_TSC_ENABLE rdtsc() == 1221707595418 prctl(PR_SET_TSC, PR_TSC_ENABLE) rdtsc() == 1221707621154 prctl(PR_SET_TSC, PR_TSC_SIGSEGV) rdtsc() == [ SIG_SEGV ] prctl(PR_GET_TSC, &tsc_val); tsc_val == PR_TSC_SIGSEGV prctl(PR_SET_TSC, PR_TSC_ENABLE) rdtsc() == 1221707702746 ---------------------------------------------------------------- I get an incorrect bogomips evaluation in /proc/cpuinfo, about ahalf of what should be reported. TSC is of course not available as a clocksource and there are now TSC related messages in dmesg. However, I can find oops like these in early dmesg [ 0.020000] Calibrating delay loop... 1795.68 BogoMIPS (lpj=8978432) [ 0.290000] ------------[ cut here ]------------ [ 0.290000] WARNING: at /home/larchey/linux-2.6.32-ovz/arch/x86/include/asm/tsc.h:27 calibrate_delay+0x291/0x367() [ 0.290000] Hardware name: KM266-8235 [ 0.290000] Modules linked in: [ 0.290000] Pid: 0, comm: swapper Not tainted 2.6.32.25-ovz-notsc-hard #4 [ 0.290000] Call Trace: [ 0.290000] [<c129240c>] ? printk+0x18/0x1c [ 0.290000] [<c102498d>] warn_slowpath_common+0x6d/0xa0 [ 0.290000] [<c13c1e7b>] ? calibrate_delay+0x291/0x367 [ 0.290000] [<c13c1e7b>] ? calibrate_delay+0x291/0x367 [ 0.290000] [<c10249d5>] warn_slowpath_null+0x15/0x20 [ 0.290000] [<c13c1e7b>] calibrate_delay+0x291/0x367 [ 0.290000] [<c13a631e>] ? tsc_init+0xf/0x186 [ 0.290000] [<c103e9bb>] ? ktime_get+0x5b/0xf0 [ 0.290000] [<c13a0652>] start_kernel+0x244/0x2b3 [ 0.290000] [<c13a01a2>] ? unknown_bootoption+0x0/0x193 [ 0.290000] [<c13a009e>] i386_start_kernel+0x9e/0xa5 [ 0.290000] ---[ end trace 4eaa2a86a8e2da22 ]--- [ 0.300000] Cycles are stuck! Some statistics will not be available. -------------------------------------------------------------------------------- # ls /proc/acpi/processor/*/power /proc/acpi/processor/CPU0/power # cat /proc/acpi/processor/*/power active state: C0 max_cstate: C1 maximum allowed latency: 2000000000 usec states: C1: type[C1] promotion[--] demotion[--] latency[000] usage[00000000] duration[00000000000000000000] -------------------------------------------------------------------------------- # ls -al /sys/devices/system/cpu/cpu*/cpuidle/state*/* ls: cannot access /sys/devices/system/cpu/cpu*/cpuidle/state*/*: No such file or directory # cat /sys/devices/system/cpu/cpuidle/current_driver acpi_idle -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
