[PATCH] sched_clock vs tsc_disable

From: Rusty Russell
Date: Thu May 17 2007 - 22:42:45 EST


(Not sure who's code this is, but it's in 2.6.22-rc1-mm1):

If you set tsc_disable (eg "notsc" on cmdline), sched-clock.c gives a
divide by zero on boot.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

diff -r fd2ae7085ca2 arch/i386/kernel/sched-clock.c
--- a/arch/i386/kernel/sched-clock.c Fri May 18 11:04:27 2007 +1000
+++ b/arch/i386/kernel/sched-clock.c Fri May 18 12:12:24 2007 +1000
@@ -103,7 +103,7 @@ static void resync_sc_freq(struct sc_dat
static void resync_sc_freq(struct sc_data *sc, unsigned int newfreq)
{
sc->sync_base = jiffies;
- if (!cpu_has_tsc) {
+ if (!cpu_has_tsc || tsc_disable) {
sc->unstable = 1;
return;
}


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