Pin ar.kr2 of each CPU, so that smp_processor_id can use it. This will save some memory foot-print when smp_procerror_id() is called.
This is also useful for implement sys_getcpu in fast path. I have simply tested the patch by boot on a 16p system then try offline and online some CPUs through /sys/. Signed-off-by: Zou Nan hai <[EMAIL PROTECTED]> diff -Nraup linux-2.6.20/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c --- linux-2.6.20/arch/ia64/kernel/setup.c 2007-02-04 13:44:54.000000000 -0500 +++ b/arch/ia64/kernel/setup.c 2007-02-07 23:30:03.000000000 -0500 @@ -458,6 +458,9 @@ early_param("elfcorehdr", parse_elfcoreh void __init setup_arch (char **cmdline_p) { + /* setup SMP processor id */ + ia64_set_kr(IA64_KR_CPU_ID, (current_thread_info()->cpu)); + unw_init(); ia64_patch_vtop((u64) __start___vtop_patchlist, (u64) __end___vtop_patchlist); diff -Nraup linux-2.6.20/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c --- linux-2.6.20/arch/ia64/kernel/smpboot.c 2007-02-04 13:44:54.000000000 -0500 +++ b/arch/ia64/kernel/smpboot.c 2007-02-07 23:29:44.000000000 -0500 @@ -445,8 +445,12 @@ smp_callin (void) int __devinit start_secondary (void *unused) { + /* setup SMP processor id */ + ia64_set_kr(IA64_KR_CPU_ID, (current_thread_info()->cpu)); + /* Early console may use I/O ports */ ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase)); + Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id()); efi_map_pal_code(); cpu_init(); diff -Nraup linux-2.6.20/include/asm-ia64/kregs.h b/include/asm-ia64/kregs.h --- linux-2.6.20/include/asm-ia64/kregs.h 2007-02-04 13:44:54.000000000 -0500 +++ b/include/asm-ia64/kregs.h 2007-02-07 23:28:21.000000000 -0500 @@ -14,6 +14,7 @@ */ #define IA64_KR_IO_BASE 0 /* ar.k0: legacy I/O base address */ #define IA64_KR_TSSD 1 /* ar.k1: IVE uses this as the TSSD */ +#define IA64_KR_CPU_ID 2 /* ar.k2: Processor ID */ #define IA64_KR_PER_CPU_DATA 3 /* ar.k3: physical per-CPU base */ #define IA64_KR_CURRENT_STACK 4 /* ar.k4: what's mapped in IA64_TR_CURRENT_STACK */ #define IA64_KR_FPU_OWNER 5 /* ar.k5: fpu-owner (UP only, at the moment) */ diff -Nraup linux-2.6.20/include/asm-ia64/smp.h b/include/asm-ia64/smp.h --- linux-2.6.20/include/asm-ia64/smp.h 2007-02-04 13:44:54.000000000 -0500 +++ b/include/asm-ia64/smp.h 2007-02-08 00:53:58.000000000 -0500 @@ -45,7 +45,7 @@ ia64_get_lid (void) #define SMP_IRQ_REDIRECTION (1 << 0) #define SMP_IPI_REDIRECTION (1 << 1) -#define raw_smp_processor_id() (current_thread_info()->cpu) +#define raw_smp_processor_id() (ia64_get_kr(IA64_KR_CPU_ID)) extern struct smp_boot_data { int cpu_count; - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html