Messages in this thread Patch in this message | | | Date | Fri, 11 Apr 2014 15:42:46 +0200 | From | Peter Zijlstra <> | Subject | [RFC][PATCH 3/8] sched,idle,ia64: 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.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> --- arch/ia64/include/asm/thread_info.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/ia64/include/asm/thread_info.h +++ b/arch/ia64/include/asm/thread_info.h @@ -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__
| |