On Thu, Apr 04, 2019 at 04:39:43PM +0200, Borislav Petkov wrote: > On Wed, Apr 03, 2019 at 02:21:47PM -0700, Fenghua Yu wrote: > > cpu_caps_cleared and cpu_caps_set may not be aligned to unsigned long. > > Atomic operations (i.e. set_bit and clear_bit) on the bitmaps may access > > Please end function names with parentheses. Sure. > > > two cache lines (a.k.a. split lock) and lock the bus to block all memory > > not "lock the bus" but "cause the CPU to do a bus lock... " Sure. > > > accesses from other processors to ensure atomicity. > > > > To avoid the overall performance degradation from the bus locking, align > > the two variables to unsigned long. > > > > Defining the variables as unsigned long may also fix the issue because > > they are naturally aligned to unsigned long. But that needs additional > > code changes. Adding __aligned(unsigned long) is a simpler fix. > > > > Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> > > --- > > arch/x86/kernel/cpu/common.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > With the above nitpicks addressed: > > Reviewed-by: Borislav Petkov <bp@xxxxxxx> Thank you for your review! -Fenghua
