[PATCH] x86-64: make pda's cpunumber and nodenumber unsigned

From: Jan Beulich
Date: Thu Dec 13 2007 - 04:10:29 EST


This generally allows better code to be generated, since the zero-
extension during 32-bit operations comes for free (needed when the
result is used as array index or similar), whereas sign extension must
be done explicitly and frequently requires a one byte larger
instruction due to the necessary rex64 prefix.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

include/asm-x86/pda.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-2.6.24-rc5/include/asm-x86/pda.h 2007-12-12 16:48:43.000000000 +0100
+++ 2.6.24-rc5-x86_64-unsigned-cpu/include/asm-x86/pda.h 2007-12-07 15:32:15.000000000 +0100
@@ -15,14 +15,14 @@ struct x8664_pda {
unsigned long kernelstack; /* 16 top of kernel stack for current */
unsigned long oldrsp; /* 24 user rsp for system call */
int irqcount; /* 32 Irq nesting counter. Starts with -1 */
- int cpunumber; /* 36 Logical CPU number */
+ unsigned int cpunumber; /* 36 Logical CPU number */
#ifdef CONFIG_CC_STACKPROTECTOR
unsigned long stack_canary; /* 40 stack canary value */
/* gcc-ABI: this canary MUST be at
offset 40!!! */
#endif
char *irqstackptr;
- int nodenumber; /* number of current node */
+ unsigned int nodenumber; /* number of current node */
unsigned int __softirq_pending;
unsigned int __nmi_count; /* number of NMI on this CPUs */
short mmu_state;



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