From 3da757daf86e498872855f0b5e101f763ba79499 Mon Sep 17 00:00:00 2001 From: Alok Kataria Date: Fri, 20 Jun 2008 15:06:33 -0700 Subject: x86: use cpu_khz for loops_per_jiffy calculation On the x86 platform we can use the value of tsc_khz computed during tsc calibration to calculate the loops_per_jiffy value. Its very important to keep the error in lpj values to minimum as any error in that may result in kernel panic in check_timer. In virtualization environment, On a highly overloaded host the guest delay calibration may sometimes result in errors beyond the ~50% that timer_irq_works can handle, resulting in the guest panicking. Does some formating changes to lpj_setup code to now have a single printk to print the bogomips value. We do this only for the boot processor because the AP's can have different base frequencies or the BIOS might boot a AP at a different frequency. Signed-off-by: Alok N Kataria Cc: Arjan van de Ven Cc: Daniel Hecht Cc: Tim Mann Cc: Zach Amsden Cc: Sahil Rihan Signed-off-by: Ingo Molnar --- arch/x86/kernel/time_64.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/time_64.c') diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index c737849e2ef7..12b4a71bd074 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -123,6 +123,8 @@ void __init time_init(void) (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) cpu_khz = calculate_cpu_khz(); + lpj_tsc = ((unsigned long)tsc_khz * 1000)/HZ; + if (unsynchronized_tsc()) mark_tsc_unstable("TSCs unsynchronized"); -- cgit v1.2.3