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sched/idle, ia64: Switch from TS_POLLING to TIF_POLLING_NRFLAG

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Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-ia64@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-6633akuird5hi3si4gbegkm8@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2014-04-11 09:59:08 +02:00 committed by Ingo Molnar
parent b3a8cb18ce
commit 0407542533
1 changed files with 2 additions and 1 deletions
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3
arch/ia64/include/asm/thread_info.h
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@ -107,6 +107,7 @@ struct thread_info {
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
#define TIF_RESTORE_RSE 21 /* user RBS is newer than kernel RBS */
#define TIF_POLLING_NRFLAG 22 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
@ -118,6 +119,7 @@ struct thread_info {
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED)
#define _TIF_RESTORE_RSE (1 << TIF_RESTORE_RSE)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
/* "work to do on user-return" bits */
#define TIF_ALLWORK_MASK (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\
@ -125,7 +127,6 @@ 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 TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */
#ifndef __ASSEMBLY__