From 495ab9c045e1b0e5c82951b762257fe1c9d81564 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@suse.de>
Date: Mon, 26 Jun 2006 13:59:11 +0200
Subject: [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>
---
include/asm-ia64/thread_info.h | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'include/asm-ia64')
diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h
index e5392c4d30c..8bc9869e576 100644
--- a/include/asm-ia64/thread_info.h
+++ b/include/asm-ia64/thread_info.h
@@ -27,6 +27,7 @@ struct thread_info {
__u32 flags; /* thread_info flags (see TIF_*) */
__u32 cpu; /* current CPU */
__u32 last_cpu; /* Last CPU thread ran on */
+ __u32 status; /* Thread synchronous flags */
mm_segment_t addr_limit; /* user-level address space limit */
int preempt_count; /* 0=premptable, <0=BUG; will also serve as bh-counter */
struct restart_block restart_block;
@@ -103,4 +104,8 @@ struct thread_info {
/* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
+#define TS_POLLING 1 /* true if in idle loop and not sleeping */
+
+#define tsk_is_polling(t) ((t)->thread_info->status & TS_POLLING)
+
#endif /* _ASM_IA64_THREAD_INFO_H */
--
cgit