diff options
| author | Alok Kataria <akataria@vmware.com> | 2008-06-21 02:06:33 +0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-24 00:51:33 +0400 |
| commit | 3da757daf86e498872855f0b5e101f763ba79499 (patch) | |
| tree | bffffafed7322c66a1b886b661cfd8a8a7f5a924 /include/linux/delay.h | |
| parent | e01b70ef3eb3080fecc35e15f68cd274c0a48163 (diff) | |
| download | linux-3da757daf86e498872855f0b5e101f763ba79499.tar.xz | |
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 <akataria@vmware.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Daniel Hecht <dhecht@vmware.com>
Cc: Tim Mann <mann@vmware.com>
Cc: Zach Amsden <zach@vmware.com>
Cc: Sahil Rihan <srihan@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/delay.h')
| -rw-r--r-- | include/linux/delay.h | 1 |
1 files changed, 1 insertions, 0 deletions
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); |