sched: Prevent compiler from optimising the sched_avg_update() loop

GCC 4.4.1 on ARM has been observed to replace the while loop in
sched_avg_update with a call to uldivmod, resulting in the
following build failure at link-time:

kernel/built-in.o: In function `sched_avg_update':
 kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod'
 kernel/sched.c:1261: undefined reference to `__aeabi_uldivmod'
make: *** [.tmp_vmlinux1] Error 1

This patch introduces a fake data hazard to the loop body to
prevent the compiler optimising the loop away.

Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Russell King <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions