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 --- include/linux/delay.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/delay.h') diff --git a/include/linux/delay.h b/include/linux/delay.h index 54552d21296e..01aec60590ab 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -41,6 +41,7 @@ static inline void ndelay(unsigned long x) #define ndelay(x) ndelay(x) #endif +extern unsigned long lpj_tsc; void calibrate_delay(void); void msleep(unsigned int msecs); unsigned long msleep_interruptible(unsigned int msecs); -- cgit v1.2.3