On 2013-02-19 13:20, David Shwatrz wrote:
We have:
#define cpu_relax() asm volatile(rep; nop)
in arch/x86/boot/boot.h.
Why don't we use the PAUSE assembler instruction here ?
If you dig further into the Intel x86 manual, the machine instructions
'pause' and 'rep;nop' actually use the
On Tue, Feb 19, 2013 at 7:20 PM, David Shwatrz dshwa...@gmail.com wrote:
Hi, kernel newbies,
We have:
#define cpu_relax() asm volatile(rep; nop)
in arch/x86/boot/boot.h.
Why don't we use the PAUSE assembler instruction here ?
Just guessing, maybe rep+nop could do better power saving
On Wed, 20 Feb 2013 01:58:17 +0700, Mulyadi Santosa said:
On Tue, Feb 19, 2013 at 7:20 PM, David Shwatrz dshwa...@gmail.com wrote:
Hi, kernel newbies,
We have:
#define cpu_relax() asm volatile(rep; nop)
in arch/x86/boot/boot.h.
Why don't we use the PAUSE assembler instruction
On Tue, Feb 19, 2013 at 02:20:11PM +0200, David Shwatrz wrote:
Hi, kernel newbies,
We have:
#define cpu_relax() asm volatile(rep; nop)
in arch/x86/boot/boot.h.
Why don't we use the PAUSE assembler instruction here ?
But rep_nop and pause ought to be the same, why we change it? If it