David Howells 4594bf159f [PATCH] WorkStruct: Use direct assignment rather than cmpxchg() ... Use direct assignment rather than cmpxchg() as the latter is unavailable and unimplementable on some platforms and is actually unnecessary. The use of cmpxchg() was to guard against two possibilities, neither of which can actually occur: (1) The pending flag may have been unset or may be cleared. However, given where it's called, the pending flag is _always_ set. I don't think it can be unset whilst we're in set_wq_data(). Once the work is enqueued to be actually run, the only way off the queue is for it to be actually run. If it's a delayed work item, then the bit can't be cleared by the timer because we haven't started the timer yet. Also, the pending bit can't be cleared by cancelling the delayed work _until_ the work item has had its timer started. (2) The workqueue pointer might change. This can only happen in two cases: (a) The work item has just been queued to actually run, and so we're protected by the appropriate workqueue spinlock. (b) A delayed work item is being queued, and so the timer hasn't been started yet, and so no one else knows about the work item or can access it (the pending bit protects us). Besides, set_wq_data() _sets_ the workqueue pointer unconditionally, so it can be assigned instead. So, replacing the set_wq_data() with a straight assignment would be okay in most cases. The problem is where we end up tangling with test_and_set_bit() emulated using spinlocks, and even then it's not a problem _provided_ test_and_set_bit() doesn't attempt to modify the word if the bit was set. If that's a problem, then a bitops-proofed assignment will be required - equivalent to atomic_set() vs other atomic_xxx() ops. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2006-12-09 12:25:08 -08:00
..
irq	[PATCH] CPEI gets warning at kernel/irq/migration.c:27/move_masked_irq()	2006-12-08 08:28:37 -08:00
power	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
time	[PATCH] time_adjust cleared before use	2006-10-28 11:30:55 -07:00
.gitignore	gitignore: ignore more generated files	2006-01-03 11:35:26 +01:00
acct.c	[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:42 -08:00
audit.c	[PATCH] Add include/linux/freezer.h and move definitions from sched.h	2006-12-07 08:39:27 -08:00
audit.h	[PATCH] audit: AUDIT_PERM support	2006-09-11 13:32:30 -04:00
auditfilter.c	[PATCH] kernel core: replace kmalloc+memset with kzalloc	2006-12-07 08:39:41 -08:00
auditsc.c	[PATCH] struct path: convert kernel	2006-12-08 08:28:46 -08:00
capability.c	[PATCH] pidspace: is_init()	2006-09-29 09:18:12 -07:00
compat.c	[PATCH] Create compat_sys_migrate_pages	2006-11-03 12:27:59 -08:00
configs.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
cpu.c	[PATCH] suspend: don't change cpus_allowed for task initiating the suspend	2006-12-07 08:39:28 -08:00
cpuset.c	[PATCH] struct path: convert kernel	2006-12-08 08:28:46 -08:00
delayacct.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
dma.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
exec_domain.c	Remove obsolete #include <linux/config.h>	2006-06-30 19:25:36 +02:00
exit.c	[PATCH] session_of_pgrp: kill unnecessary do_each_task_pid(PIDTYPE_PGID)	2006-12-08 08:28:52 -08:00
extable.c	[PATCH] symbol_put_addr() locks kernel	2006-05-15 11:20:55 -07:00
fork.c	[PATCH] rename struct namespace to struct mnt_namespace	2006-12-08 08:28:51 -08:00
futex_compat.c	[PATCH] __user annotations: futex	2006-10-10 15:37:22 -07:00
futex.c	[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:42 -08:00
hrtimer.c	[PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode	2006-09-29 09:18:15 -07:00
itimer.c	[PATCH] hrtimers: remove data field	2006-03-26 08:57:03 -08:00
kallsyms.c	[PATCH] move kallsyms data to .rodata	2006-12-08 08:28:37 -08:00
Kconfig.hz	[PATCH] HZ: 300Hz support	2006-12-07 08:39:36 -08:00
Kconfig.preempt	[PATCH] sched: voluntary kernel preemption	2005-06-25 16:24:45 -07:00
kexec.c	Merge branch 'release' of master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6	2006-12-07 15:39:22 -08:00
kfifo.c	[PATCH] memory ordering in __kfifo primitives	2006-09-29 09:18:13 -07:00
kmod.c	[PATCH] rename struct namespace to struct mnt_namespace	2006-12-08 08:28:51 -08:00
kprobes.c	[PATCH] kprobes: enable booster on the preemptible kernel	2006-12-07 08:39:38 -08:00
ksysfs.c	Remove obsolete #include <linux/config.h>	2006-06-30 19:25:36 +02:00
kthread.c	WorkStruct: Pass the work_struct pointer instead of context data	2006-11-22 14:55:48 +00:00
latency.c	[PATCH] severing module.h->sched.h	2006-12-04 02:00:22 -05:00
lockdep_internals.h	[PATCH] lockdep: more chains	2006-12-07 08:39:43 -08:00
lockdep_proc.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
lockdep.c	Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6	2006-12-07 08:59:11 -08:00
Makefile	[PATCH] srcu-3: RCU variant permitting read-side blocking	2006-10-04 07:55:30 -07:00
module.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
mutex-debug.c	[PATCH] lockdep: show more details about self-test failures	2006-12-07 08:39:43 -08:00
mutex-debug.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
mutex.c	[PATCH] lockdep: avoid lockdep warning in md	2006-12-08 08:28:39 -08:00
mutex.h	[PATCH] lockdep: prove mutex locking correctness	2006-07-03 15:27:04 -07:00
nsproxy.c	[PATCH] to nsproxy	2006-12-08 08:28:52 -08:00
panic.c	[PATCH] x86: Clean up x86 NMI sysctls	2006-09-30 01:47:55 +02:00
params.c	[PATCH] module_subsys: initialize earlier	2006-09-29 09:18:08 -07:00
pid.c	[PATCH] add child reaper to pid_namespace	2006-12-08 08:28:52 -08:00
posix-cpu-timers.c	[PATCH] posix-cpu-timers: prevent signal delivery starvation	2006-10-17 08:18:43 -07:00
posix-timers.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
printk.c	[PATCH] add ignore_loglevel boot option	2006-12-07 08:39:47 -08:00
profile.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
ptrace.c	[PATCH] pidspace: is_init()	2006-09-29 09:18:12 -07:00
rcupdate.c	[PATCH] rcu: add a prefetch() in rcu_do_batch()	2006-12-07 08:39:40 -08:00
rcutorture.c	[PATCH] Add Sparse annotations to SRCU wrapper functions in rcutorture	2006-12-07 08:39:44 -08:00
relay.c	[PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:42 -08:00
resource.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
rtmutex_common.h	[PATCH] pi-futex: futex_lock_pi/futex_unlock_pi support	2006-06-27 17:32:47 -07:00
rtmutex-debug.c	Remove all inclusions of <linux/config.h>	2006-10-04 03:38:54 -04:00
rtmutex-debug.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
rtmutex-tester.c	[PATCH] Add include/linux/freezer.h and move definitions from sched.h	2006-12-07 08:39:27 -08:00
rtmutex.c	[PATCH] clean up and remove some extra spinlocks from rtmutex	2006-09-29 09:18:09 -07:00
rtmutex.h	[PATCH] lockdep: better lock debugging	2006-07-03 15:27:01 -07:00
rwsem.c	[PATCH] lockdep: prove rwsem locking correctness	2006-07-03 15:27:04 -07:00
sched.c	[PATCH] struct seq_operations and struct file_operations constification	2006-12-07 08:39:46 -08:00
seccomp.c	Linux-2.6.12-rc2	2005-04-16 15:20:36 -07:00
signal.c	[PATCH] add child reaper to pid_namespace	2006-12-08 08:28:52 -08:00
softirq.c	[PATCH] softirq: remove BUG_ONs which can incorrectly trigger	2006-12-07 08:39:43 -08:00
softlockup.c	[PATCH] check return value of cpu_callback	2006-09-29 09:18:14 -07:00
spinlock.c	[PATCH] lockdep: spin_lock_irqsave_nested()	2006-11-25 13:28:34 -08:00
srcu.c	[PATCH] SRCU: report out-of-memory errors	2006-10-04 07:55:30 -07:00
stacktrace.c	[PATCH] lockdep: stacktrace subsystem, core	2006-07-03 15:27:02 -07:00
stop_machine.c	[PATCH] stop_machine.c copyright	2006-09-29 09:18:24 -07:00
sys_ni.c	[PATCH] Create compat_sys_migrate_pages	2006-11-03 12:27:59 -08:00
sys.c	[PATCH] sys_setpgid: eliminate unnecessary do_each_task_pid(PIDTYPE_PGID)	2006-12-08 08:28:52 -08:00
sysctl.c	[PATCH] sysctl: fix sys_sysctl interface of ipc sysctls	2006-12-08 08:29:03 -08:00
taskstats.c	[PATCH] taskstats: cleanup reply assembling	2006-12-07 08:39:34 -08:00
time.c	[PATCH] NTP: Move all the NTP related code to ntp.c	2006-10-01 00:39:26 -07:00
timer.c	[PATCH] kill wall_jiffies	2006-10-01 00:39:27 -07:00
tsacct.c	[PATCH] xacct_add_tsk: fix pure theoretical ->mm use-after-free	2006-10-30 12:08:41 -08:00
uid16.c	[PATCH] Add more prevent_tail_call()	2006-04-19 16:27:18 -07:00
unwind.c	[PATCH] unwinder: move .eh_frame to RODATA	2006-12-07 02:14:19 +01:00
user.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
utsname.c	[PATCH] namespaces: utsname: implement CLONE_NEWUTS flag	2006-10-02 07:57:22 -07:00
wait.c	[PATCH] uninline init_waitqueue_head()	2006-07-10 13:24:25 -07:00
workqueue.c	[PATCH] WorkStruct: Use direct assignment rather than cmpxchg()	2006-12-09 12:25:08 -08:00