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 <t...@linutronix.de> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Richard Henderson <r...@twiddle.net> Signed-off-by: Peter Zijlstra <pet...@infradead.org> --- arch/alpha/include/asm/thread_info.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -73,12 +73,14 @@ register struct thread_info *__current_t #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_t #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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
