sched/idle, tile: 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 <peterz@infradead.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-35zzwlvwr7cp8xj196y10yyx@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2014-04-11 09:59:13 +02:00 committed by Ingo Molnar
parent 2a705ad65c
commit b3a8cb18ce

View File

@ -129,6 +129,7 @@ extern void _cpu_idle(void);
#define TIF_MEMDIE 7 /* OOM killer at work */
#define TIF_NOTIFY_RESUME 8 /* callback before returning to user */
#define TIF_SYSCALL_TRACEPOINT 9 /* syscall tracepoint instrumentation */
#define TIF_POLLING_NRFLAG 10 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
@ -140,6 +141,7 @@ extern void _cpu_idle(void);
#define _TIF_MEMDIE (1<<TIF_MEMDIE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* Work to do on any return to user space. */
#define _TIF_ALLWORK_MASK \
@ -162,7 +164,6 @@ extern void _cpu_idle(void);
#ifdef __tilegx__
#define TS_COMPAT 0x0001 /* 32-bit compatibility mode */
#endif
#define TS_POLLING 0x0004 /* in idle loop but not sleeping */
#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal */
#ifndef __ASSEMBLY__