sched/idle, alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG

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 <[email protected]>
Acked-by: Richard Henderson <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: 蔡正龙 <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Peter Zijlstra 2014-04-11 09:59:17 +02:00 • committed by Ingo Molnar
commit 2a705ad65c

View file

@ -73,12 +73,14 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define TIF_SYSCALL_AUDIT 4 /* syscall audit active */
#define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */
#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 14 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* Work to do on interrupt/exception return. */
#define _TIF_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
@ -92,8 +94,6 @@ register struct thread_info *__current_thread_info __asm__("$8");
#define TS_UAC_NOFIX 0x0002 /* ! flags as they match */
#define TS_UAC_SIGBUS 0x0004 /* ! userspace part of 'osf_sysinfo' */
#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
#define TS_POLLING 0x0010 /* idle task polling need_resched,
skip sending interrupt */
#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK 1