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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1a82e9e1d0
Introduce separate queues for operations that do not modify the semaphore values. Advantages: - Simpler logic in check_restart(). - Faster update_queue(): Right now, all wait-for-zero operations are always tested, even if the semaphore value is not 0. - wait-for-zero gets again priority, as in linux <=3.0.9 Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Rik van Riel <riel@redhat.com> Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
#ifndef _LINUX_SEM_H
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#define _LINUX_SEM_H
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#include <linux/atomic.h>
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#include <linux/rcupdate.h>
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#include <linux/cache.h>
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#include <uapi/linux/sem.h>
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struct task_struct;
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/* One sem_array data structure for each set of semaphores in the system. */
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struct sem_array {
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struct kern_ipc_perm ____cacheline_aligned_in_smp
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sem_perm; /* permissions .. see ipc.h */
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time_t sem_otime; /* last semop time */
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time_t sem_ctime; /* last change time */
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struct sem *sem_base; /* ptr to first semaphore in array */
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struct list_head pending_alter; /* pending operations */
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/* that alter the array */
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struct list_head pending_const; /* pending complex operations */
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/* that do not alter semvals */
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struct list_head list_id; /* undo requests on this array */
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int sem_nsems; /* no. of semaphores in array */
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int complex_count; /* pending complex operations */
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};
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#ifdef CONFIG_SYSVIPC
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struct sysv_sem {
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struct sem_undo_list *undo_list;
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};
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extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
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extern void exit_sem(struct task_struct *tsk);
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#else
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struct sysv_sem {
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/* empty */
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};
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static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
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{
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return 0;
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}
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static inline void exit_sem(struct task_struct *tsk)
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{
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return;
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}
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#endif
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#endif /* _LINUX_SEM_H */
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