[PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status
During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.
Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.
Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
index 8420ed1..fdbc7f4 100644
--- a/include/asm-i386/thread_info.h
+++ b/include/asm-i386/thread_info.h
@@ -140,8 +140,7 @@
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */
-#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
-#define TIF_MEMDIE 17
+#define TIF_MEMDIE 16
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
@@ -153,7 +152,6 @@
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK \
@@ -170,6 +168,9 @@
* have to worry about atomic accesses.
*/
#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
+#define TS_POLLING 0x0002 /* True if in idle loop and not sleeping */
+
+#define tsk_is_polling(t) ((t)->thread_info->status & TS_POLLING)
#endif /* __KERNEL__ */