| kern_rwlock.c (177912) | kern_rwlock.c (179334) |
|---|---|
| 1/*- 2 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 18 unchanged lines hidden (view full) --- 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * Machine independent bits of reader/writer lock implementation. 32 */ 33 34#include <sys/cdefs.h> | 1/*- 2 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 18 unchanged lines hidden (view full) --- 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * Machine independent bits of reader/writer lock implementation. 32 */ 33 34#include <sys/cdefs.h> |
| 35__FBSDID("$FreeBSD: head/sys/kern/kern_rwlock.c 177912 2008-04-04 10:00:46Z jeff $"); | 35__FBSDID("$FreeBSD: head/sys/kern/kern_rwlock.c 179334 2008-05-27 00:27:50Z attilio $"); |
| 36 37#include "opt_ddb.h" 38#include "opt_no_adaptive_rwlocks.h" 39 40#include <sys/param.h> 41#include <sys/ktr.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> --- 602 unchanged lines hidden (view full) --- 646 if (TD_IS_RUNNING(owner)) { 647 turnstile_cancel(ts); 648 cpu_spinwait(); 649 continue; 650 } 651 } 652#endif 653 /* | 36 37#include "opt_ddb.h" 38#include "opt_no_adaptive_rwlocks.h" 39 40#include <sys/param.h> 41#include <sys/ktr.h> 42#include <sys/kernel.h> 43#include <sys/lock.h> --- 602 unchanged lines hidden (view full) --- 646 if (TD_IS_RUNNING(owner)) { 647 turnstile_cancel(ts); 648 cpu_spinwait(); 649 continue; 650 } 651 } 652#endif 653 /* |
| 654 * If the lock was released while waiting for the turnstile 655 * chain lock retry. | 654 * Check for the waiters flags about this rwlock. 655 * If the lock was released, without maintain any pending 656 * waiters queue, simply try to acquire it. 657 * If a pending waiters queue is present, claim the lock 658 * ownership and maintain the pending queue. |
| 656 */ 657 x = v & (RW_LOCK_WAITERS | RW_LOCK_WRITE_SPINNER); 658 if ((v & ~x) == RW_UNLOCKED) { 659 x &= ~RW_LOCK_WRITE_SPINNER; 660 if (atomic_cmpset_acq_ptr(&rw->rw_lock, v, tid | x)) { 661 if (x) 662 turnstile_claim(ts); 663 else --- 365 unchanged lines hidden --- | 659 */ 660 x = v & (RW_LOCK_WAITERS | RW_LOCK_WRITE_SPINNER); 661 if ((v & ~x) == RW_UNLOCKED) { 662 x &= ~RW_LOCK_WRITE_SPINNER; 663 if (atomic_cmpset_acq_ptr(&rw->rw_lock, v, tid | x)) { 664 if (x) 665 turnstile_claim(ts); 666 else --- 365 unchanged lines hidden --- |