The sched_clock code uses 2 levels of function pointers, sched_clock_func() and read_sched_clock() but the no sched_clock check in postinit() just checks read_sched_clock().
This leads to kernel falling back to jiffy based sched clock even in presence of sched_clock_func() which is not desirable. Fix the postinit() check to avoid the issue. Probably the issue is hidden so far on most of the arm SOCs because of already existing sched_clock registrations apart from arch_timer sched_clock. One can reproduce the issue by just have arch_timer as sched_clock Cc: Stephen Boyd <[email protected]> Cc: John Stultz <[email protected]> Cc: Russell King <[email protected]> Cc: Will Deacon <[email protected]> Cc: Rob Herring <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Santosh Shilimkar <[email protected]> --- kernel/time/sched_clock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c index 0b479a6..15c4d78 100644 --- a/kernel/time/sched_clock.c +++ b/kernel/time/sched_clock.c @@ -179,7 +179,8 @@ void __init sched_clock_postinit(void) * If no sched_clock function has been provided at that point, * make it the final one one. */ - if (read_sched_clock == jiffy_sched_clock_read) + if ((read_sched_clock == jiffy_sched_clock_read) && + (sched_clock_func == sched_clock_32)) setup_sched_clock(jiffy_sched_clock_read, 32, HZ); sched_clock_poll(sched_clock_timer.data); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
