kernel/linux.git/include/linux/wait.h, branch v2.6.28

wait: kill is_sync_wait()

2008-10-16T18:21:31+00:00

is_sync_wait() is used to distinguish between sync and async waits. Basically sync waits are the ones initialized with init_waitqueue_entry() and async ones with init_waitqueue_func_entry(). The sync/async distinction is used only in prepare_to_wait[_exclusive]() and its only function is to skip setting the current task state if the wait is async. This has a few problems. * No one uses it. None of func_entry users use prepare_to_wait() functions, so the code path never gets executed. * The distinction is bogus. Maybe back when func_entry is used only by aio but it's now also used by epoll and in future possibly by 9p and poll/select. * Taking @state as argument and ignoring it silenly depending on how @wait is initialized is just a bad error-prone API. * It prevents func_entry waits from using wait->private for no good reason. This patch kills is_sync_wait() and the associated code paths from prepare_to_wait[_exclusive](). As there was no user of these code paths, this patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

include/linux: Remove all users of FASTCALL() macro

2008-02-14T00:21:18+00:00

FASTCALL() is always expanded to empty, remove it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lockdep: annotate epoll

2008-02-05T17:44:07+00:00

On Sat, 2008-01-05 at 13:35 -0800, Davide Libenzi wrote: > I remember I talked with Arjan about this time ago. Basically, since 1) > you can drop an epoll fd inside another epoll fd 2) callback-based wakeups > are used, you can see a wake_up() from inside another wake_up(), but they > will never refer to the same lock instance. > Think about: > > dfd = socket(...); > efd1 = epoll_create(); > efd2 = epoll_create(); > epoll_ctl(efd1, EPOLL_CTL_ADD, dfd, ...); > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...); > > When a packet arrives to the device underneath "dfd", the net code will > issue a wake_up() on its poll wake list. Epoll (efd1) has installed a > callback wakeup entry on that queue, and the wake_up() performed by the > "dfd" net code will end up in ep_poll_callback(). At this point epoll > (efd1) notices that it may have some event ready, so it needs to wake up > the waiters on its poll wait list (efd2). So it calls ep_poll_safewake() > that ends up in another wake_up(), after having checked about the > recursion constraints. That are, no more than EP_MAX_POLLWAKE_NESTS, to > avoid stack blasting. Never hit the same queue, to avoid loops like: > > epoll_ctl(efd2, EPOLL_CTL_ADD, efd1, ...); > epoll_ctl(efd3, EPOLL_CTL_ADD, efd2, ...); > epoll_ctl(efd4, EPOLL_CTL_ADD, efd3, ...); > epoll_ctl(efd1, EPOLL_CTL_ADD, efd4, ...); > > The code "if (tncur->wq == wq || ..." prevents re-entering the same > queue/lock. Since the epoll code is very careful to not nest same instance locks allow the recursion. Signed-off-by: Peter Zijlstra Tested-by: Stefan Richter Acked-by: Davide Libenzi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Add wait_event_killable

2007-12-06T22:40:14+00:00

Signed-off-by: Matthew Wilcox

wait: Use TASK_NORMAL

2007-12-06T22:34:36+00:00

Also move wake_up_locked() to be with the related functions Signed-off-by: Matthew Wilcox

sched: clean up sleep_on() APIs

2007-07-09T16:52:01+00:00

clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar

[PATCH] lockdep: annotate DECLARE_WAIT_QUEUE_HEAD

2006-10-30T20:08:40+00:00

kernel: INFO: trying to register non-static key. kernel: the code is fine but needs lockdep annotation. kernel: turning off the locking correctness validator. kernel: [] show_trace_log_lvl+0x58/0x16a kernel: [] show_trace+0xd/0x10 kernel: [] dump_stack+0x19/0x1b kernel: [] __lock_acquire+0xf0/0x90d kernel: [] lock_acquire+0x4b/0x6b kernel: [] _spin_lock_irqsave+0x22/0x32 kernel: [] prepare_to_wait+0x17/0x4b kernel: [] lpfc_do_work+0xdd/0xcc2 [lpfc] kernel: [] kthread+0xc3/0xf2 kernel: [] kernel_thread_helper+0x5/0xb Another case of non-static lockdep keys; duplicate the paradigm set by DECLARE_COMPLETION_ONSTACK and introduce DECLARE_WAIT_QUEUE_HEAD_ONSTACK. Signed-off-by: Peter Zijlstra Cc: Greg KH Cc: Markus Lidel Acked-by: Ingo Molnar Cc: Arjan van de Ven Cc: James Bottomley Cc: Marcel Holtmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] uninline init_waitqueue_head()

2006-07-10T20:24:25+00:00

allyesconfig vmlinux size delta: text data bss dec filename 20736884 6073834 3075176 29885894 vmlinux.before 20721009 6073966 3075176 29870151 vmlinux.after ~18 bytes per callsite, 15K of text size (~0.1%) saved. (as an added bonus this also removes a lockdep annotation.) Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep: annotate waitqueues

2006-07-03T22:27:07+00:00

Create one lock class for all waitqueue locks in the kernel. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep: locking init debugging improvement

2006-07-03T22:27:02+00:00

Locking init improvement: - introduce and use __SPIN_LOCK_UNLOCKED for array initializations, to pass in the name string of locks, used by debugging Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds