powerpc: Update DSCR on all CPUs when writing sysfs dscr_default
Writing to dscr_default in sysfs doesn't actually change the DSCR -
we rely on a context switch on each CPU to do the work. There is no
guarantee we will get a context switch in a reasonable amount of time
so fire off an IPI to force an immediate change.
This issue was found with the following test case:
http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org> # 3.0+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 file changed