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Commit 3bc207d2 authored by Fenghua Yu's avatar Fenghua Yu Committed by Tony Luck
Browse files

[IA64] fsys_getcpu for IA64 



On 1.6GHz Montectio Tiger4, the following performance data is measured with
kernel built with defconfig which has NUMA configured:

Fastest sys_getcpu: 502 itc counts.
Fastest fsys_getcpu: 28 itc counts.

fsys_getcpu performance is largly impacted by whether data (node_to_cpu_map
etc) is in cache. It can take fsys_getcpu up to ~150 itc counts in cold
cache case.

Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent ddbad076

arch/ia64/kernel/asm-offsets.c

+1 −0
Original line number Original line Diff line number Diff line
@@ -35,6 +35,7 @@ void foo(void) 
	BLANK();

	BLANK();





	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));

	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));

	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));

	DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));

	DEFINE(TI_PRE_COUNT, offsetof(struct thread_info, preempt_count));





	BLANK();

	BLANK();

arch/ia64/kernel/fsys.S

+105 −0
Original line number Original line Diff line number Diff line
@@ -10,6 +10,8 @@ 
 *			probably broke it along the way... ;-)

 *			probably broke it along the way... ;-)

 * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make

 * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make

 *                      it capable of using memory based clocks without falling back to C code.

 *                      it capable of using memory based clocks without falling back to C code.

 * 08-Feb-07 Fenghua Yu Implement fsys_getcpu.

 *

 */

 */





#include <asm/asmmacro.h>

#include <asm/asmmacro.h>
@@ -505,6 +507,59 @@ EX(.fail_efault, (p15) st8 [r34]=r3) 
#endif

#endif

END(fsys_rt_sigprocmask)

END(fsys_rt_sigprocmask)





/*

 * fsys_getcpu doesn't use the third parameter in this implementation. It reads

 * current_thread_info()->cpu and corresponding node in cpu_to_node_map.

 */

ENTRY(fsys_getcpu)

	.prologue

	.altrp b6

	.body

	;;

	add r2=TI_FLAGS+IA64_TASK_SIZE,r16

	tnat.nz p6,p0 = r32			// guard against NaT argument

	add r3=TI_CPU+IA64_TASK_SIZE,r16

	;;

	ld4 r3=[r3]				// M r3 = thread_info->cpu

	ld4 r2=[r2]				// M r2 = thread_info->flags

(p6)    br.cond.spnt.few .fail_einval		// B

	;;

	tnat.nz p7,p0 = r33			// I guard against NaT argument

(p7)    br.cond.spnt.few .fail_einval		// B

#ifdef CONFIG_NUMA

	movl r17=cpu_to_node_map

	;;

EX(.fail_efault, probe.w.fault r32, 3)		// M This takes 5 cycles

EX(.fail_efault, probe.w.fault r33, 3)		// M This takes 5 cycles

	shladd r18=r3,1,r17

	;;

	ld2 r20=[r18]				// r20 = cpu_to_node_map[cpu]

	and r2 = TIF_ALLWORK_MASK,r2

	;;

	cmp.ne p8,p0=0,r2

(p8)	br.spnt.many fsys_fallback_syscall

	;;

	;;

EX(.fail_efault, st4 [r32] = r3)

EX(.fail_efault, st2 [r33] = r20)

	mov r8=0

	;;

#else

EX(.fail_efault, probe.w.fault r32, 3)		// M This takes 5 cycles

EX(.fail_efault, probe.w.fault r33, 3)		// M This takes 5 cycles

	and r2 = TIF_ALLWORK_MASK,r2

	;;

	cmp.ne p8,p0=0,r2

(p8)	br.spnt.many fsys_fallback_syscall

	;;

EX(.fail_efault, st4 [r32] = r3)

EX(.fail_efault, st2 [r33] = r0)

	mov r8=0

	;;

#endif

	FSYS_RETURN

END(fsys_getcpu)



ENTRY(fsys_fallback_syscall)

ENTRY(fsys_fallback_syscall)

	.prologue

	.prologue

	.altrp b6

	.altrp b6
@@ -878,6 +933,56 @@ fsyscall_table: 
	data8 0				// timer_delete

	data8 0				// timer_delete

	data8 0				// clock_settime

	data8 0				// clock_settime

	data8 fsys_clock_gettime	// clock_gettime

	data8 fsys_clock_gettime	// clock_gettime

	data8 0				// clock_getres		// 1255

	data8 0				// clock_nanosleep

	data8 0				// fstatfs64

	data8 0				// statfs64

	data8 0				// mbind

	data8 0				// get_mempolicy	// 1260

	data8 0				// set_mempolicy

	data8 0				// mq_open

	data8 0				// mq_unlink

	data8 0				// mq_timedsend

	data8 0				// mq_timedreceive	// 1265

	data8 0				// mq_notify

	data8 0				// mq_getsetattr

	data8 0				// kexec_load

	data8 0				// vserver

	data8 0				// waitid		// 1270

	data8 0				// add_key

	data8 0				// request_key

	data8 0				// keyctl

	data8 0				// ioprio_set

	data8 0				// ioprio_get		// 1275

	data8 0				// move_pages

	data8 0				// inotify_init

	data8 0				// inotify_add_watch

	data8 0				// inotify_rm_watch

	data8 0				// migrate_pages	// 1280

	data8 0				// openat

	data8 0				// mkdirat

	data8 0				// mknodat

	data8 0				// fchownat

	data8 0				// futimesat		// 1285

	data8 0				// newfstatat

	data8 0				// unlinkat

	data8 0				// renameat

	data8 0				// linkat

	data8 0				// symlinkat		// 1290

	data8 0				// readlinkat

	data8 0				// fchmodat

	data8 0				// faccessat

	data8 0

	data8 0							// 1295

	data8 0				// unshare

	data8 0				// splice

	data8 0				// set_robust_list

	data8 0				// get_robust_list

	data8 0				// sync_file_range	// 1300

	data8 0				// tee

	data8 0				// vmsplice

	data8 0

	data8 fsys_getcpu		// getcpu		// 1304





	// fill in zeros for the remaining entries

	// fill in zeros for the remaining entries

	.zero:

	.zero: