If the TSC has already been determined to be unstable, then checking TSC ADJUST values is a waste of time and generates unnecessary error messages. Signed-off-by: Mike Travis Reviewed-by: Dimitri Sivanich Reviewed-by: Russ Anderson Reviewed-by: Peter Zijlstra --- v2: Add check_tsc_unstable to !CONFIG_SMP case. Patches merged against 4.14.0-rc4 --- arch/x86/kernel/tsc_sync.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- linux.orig/arch/x86/kernel/tsc_sync.c +++ linux/arch/x86/kernel/tsc_sync.c @@ -52,6 +52,10 @@ void tsc_verify_tsc_adjust(bool resume) if (!boot_cpu_has(X86_FEATURE_TSC_ADJUST)) return; + /* Skip unnecessary error messages if TSC already unstable */ + if (check_tsc_unstable()) + return; + /* Rate limit the MSR check */ if (!resume && time_before(jiffies, adj->nextcheck)) return; @@ -114,6 +118,10 @@ bool __init tsc_store_and_check_tsc_adju if (!boot_cpu_has(X86_FEATURE_TSC_ADJUST)) return false; + /* Skip unnecessary error messages if TSC already unstable */ + if (check_tsc_unstable()) + return false; + rdmsrl(MSR_IA32_TSC_ADJUST, bootval); cur->bootval = bootval; cur->nextcheck = jiffies + HZ; --