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authorIngo Molnar <mingo@elte.hu>2009-06-17 13:06:17 +0200
committerIngo Molnar <mingo@elte.hu>2009-06-17 13:06:17 +0200
commita3d06cc6aa3e765dc2bf98626f87272dcf641dca (patch)
treeaa3e49b58f08d6c0ea55cdca4fb5e6c8ba6ae333 /kernel/time/clocksource.c
parent0990b1c65729012a63e0eeca93aaaafea4e9a064 (diff)
parent65795efbd380a832ae508b04dba8f8e53f0b84d9 (diff)
Merge branch 'linus' into perfcounters/core
Conflicts: arch/x86/include/asm/kmap_types.h include/linux/mm.h include/asm-generic/kmap_types.h Merge reason: We crossed changes with kmap_types.h cleanups in mainline. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/time/clocksource.c')
-rw-r--r--kernel/time/clocksource.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 80189f6f1c5..592bf584d1d 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -509,6 +509,18 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
}
}
+ /*
+ * Check to make sure we don't switch to a non-highres capable
+ * clocksource if the tick code is in oneshot mode (highres or nohz)
+ */
+ if (tick_oneshot_mode_active() &&
+ !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
+ printk(KERN_WARNING "%s clocksource is not HRT compatible. "
+ "Cannot switch while in HRT/NOHZ mode\n", ovr->name);
+ ovr = NULL;
+ override_name[0] = 0;
+ }
+
/* Reselect, when the override name has changed */
if (ovr != clocksource_override) {
clocksource_override = ovr;
@@ -537,7 +549,13 @@ sysfs_show_available_clocksources(struct sys_device *dev,
spin_lock_irq(&clocksource_lock);
list_for_each_entry(src, &clocksource_list, list) {
- count += snprintf(buf + count,
+ /*
+ * Don't show non-HRES clocksource if the tick code is
+ * in one shot mode (highres=on or nohz=on)
+ */
+ if (!tick_oneshot_mode_active() ||
+ (src->flags & CLOCK_SOURCE_VALID_FOR_HRES))
+ count += snprintf(buf + count,
max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
"%s ", src->name);
}