On 02/16/2017 11:48 AM, Peter Zijlstra wrote: > On Wed, Feb 15, 2017 at 04:37:50PM -0500, Waiman Long wrote: >> +/* >> + * Hand-optimize version for x86-64 to avoid 8 64-bit register saving and >> + * restoring to/from the stack. It is assumed that the preempted value >> + * is at an offset of 16 from the beginning of the kvm_steal_time structure >> + * which is verified by the BUILD_BUG_ON() macro below. >> + */ >> +#define PREEMPTED_OFFSET 16 > As per Andrew's suggestion, the 'right' way is something like so. Thanks for the tip. I was not aware of the asm-offsets stuff. I will update the patch to use it. Cheers, Longman
