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2a705ad65c
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: Richard Henderson <rth@twiddle.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <rth@twiddle.net> Cc: 蔡正龙 <zhenglong.cai@cs2c.com.cn> Cc: linux-alpha@vger.kernel.org Link: http://lkml.kernel.org/n/tip-9tfzr196gs0n2afxv0ga8pc3@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
149 lines
4.5 KiB
C
149 lines
4.5 KiB
C
#ifndef _ALPHA_THREAD_INFO_H
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#define _ALPHA_THREAD_INFO_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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#include <asm/processor.h>
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#include <asm/types.h>
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#include <asm/hwrpb.h>
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#include <asm/sysinfo.h>
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#endif
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#ifndef __ASSEMBLY__
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struct thread_info {
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struct pcb_struct pcb; /* palcode state */
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struct task_struct *task; /* main task structure */
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unsigned int flags; /* low level flags */
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unsigned int ieee_state; /* see fpu.h */
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struct exec_domain *exec_domain; /* execution domain */
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mm_segment_t addr_limit; /* thread address space */
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unsigned cpu; /* current CPU */
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int preempt_count; /* 0 => preemptable, <0 => BUG */
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unsigned int status; /* thread-synchronous flags */
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int bpt_nsaved;
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unsigned long bpt_addr[2]; /* breakpoint handling */
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unsigned int bpt_insn[2];
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struct restart_block restart_block;
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};
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/*
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* Macros/functions for gaining access to the thread information structure.
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*/
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.addr_limit = KERNEL_DS, \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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/* How to get the thread information struct from C. */
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register struct thread_info *__current_thread_info __asm__("$8");
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#define current_thread_info() __current_thread_info
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#endif /* __ASSEMBLY__ */
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/* Thread information allocation. */
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#define THREAD_SIZE_ORDER 1
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#define THREAD_SIZE (2*PAGE_SIZE)
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/*
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* Thread information flags:
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* - these are process state flags and used from assembly
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* - pending work-to-be-done flags come first and must be assigned to be
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* within bits 0 to 7 to fit in and immediate operand.
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*
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* TIF_SYSCALL_TRACE is known to be 0 via blbs.
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
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#define TIF_SIGPENDING 2 /* signal pending */
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#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
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#define TIF_SYSCALL_AUDIT 4 /* syscall audit active */
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#define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */
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#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
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#define TIF_POLLING_NRFLAG 14 /* idle is polling for TIF_NEED_RESCHED */
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#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
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#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
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#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
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/* Work to do on interrupt/exception return. */
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#define _TIF_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
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_TIF_NOTIFY_RESUME)
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/* Work to do on any return to userspace. */
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#define _TIF_ALLWORK_MASK (_TIF_WORK_MASK \
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| _TIF_SYSCALL_TRACE)
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#define TS_UAC_NOPRINT 0x0001 /* ! Preserve the following three */
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#define TS_UAC_NOFIX 0x0002 /* ! flags as they match */
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#define TS_UAC_SIGBUS 0x0004 /* ! userspace part of 'osf_sysinfo' */
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#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
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#ifndef __ASSEMBLY__
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#define HAVE_SET_RESTORE_SIGMASK 1
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static inline void set_restore_sigmask(void)
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{
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struct thread_info *ti = current_thread_info();
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ti->status |= TS_RESTORE_SIGMASK;
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WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
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}
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static inline void clear_restore_sigmask(void)
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{
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current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
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}
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static inline bool test_restore_sigmask(void)
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{
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return current_thread_info()->status & TS_RESTORE_SIGMASK;
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}
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static inline bool test_and_clear_restore_sigmask(void)
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{
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struct thread_info *ti = current_thread_info();
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if (!(ti->status & TS_RESTORE_SIGMASK))
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return false;
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ti->status &= ~TS_RESTORE_SIGMASK;
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return true;
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}
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#endif
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#define SET_UNALIGN_CTL(task,value) ({ \
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__u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \
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if (value & PR_UNALIGN_NOPRINT) \
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status |= TS_UAC_NOPRINT; \
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if (value & PR_UNALIGN_SIGBUS) \
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status |= TS_UAC_SIGBUS; \
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if (value & 4) /* alpha-specific */ \
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status |= TS_UAC_NOFIX; \
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task_thread_info(task)->status = status; \
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0; })
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#define GET_UNALIGN_CTL(task,value) ({ \
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__u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \
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__u32 res = 0; \
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if (status & TS_UAC_NOPRINT) \
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res |= PR_UNALIGN_NOPRINT; \
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if (status & TS_UAC_SIGBUS) \
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res |= PR_UNALIGN_SIGBUS; \
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if (status & TS_UAC_NOFIX) \
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res |= 4; \
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put_user(res, (int __user *)(value)); \
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})
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#endif /* __KERNEL__ */
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#endif /* _ALPHA_THREAD_INFO_H */
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