search for: uregs_r15

This set of patches converts the way frames gets created from using PUSHes/POPs to using MOVes, thus allowing (in certain cases) to avoid saving/restoring part of the register set. While the place where the (small) win from this comes from varies between CPUs, the net effect is a 1 to 2% reduction on a combined interruption entry and exit when the full state save can be avoided. 1: use MOV

...efine __L8(_x) (((_x) & 0x000000f0) ? ( 4 + __L4( (_x)>> 4)) : __L4( _x)) -#define __L16(_x) (((_x) & 0x0000ff00) ? ( 8 + __L8( (_x)>> 8)) : __L8( _x)) -#define LOG_2(_x) (((_x) & 0xffff0000) ? (16 + __L16((_x)>>16)) : __L16(_x)) - void __dummy__(void) { OFFSET(UREGS_r15, struct cpu_user_regs, r15); diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h index 190d96b..c6a78b6 100644 --- a/xen/include/xen/bitops.h +++ b/xen/include/xen/bitops.h @@ -175,4 +175,11 @@ static inline __u32 ror32(__u32 word, unsigned int shift) return (word >> shift)...

This round implements all of the review comments from V2 and all patches are now acked. Unless there are any objections I intend to apply later this morning. Ian.