aboutsummaryrefslogtreecommitdiff
path: root/include/linux/wait.h
AgeCommit message (Collapse)Author
2008-02-05lockdep: annotate epollPeter Zijlstra
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 <a.p.zijlstra@chello.nl> Tested-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-06Add wait_event_killableMatthew Wilcox
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06wait: Use TASK_NORMALMatthew Wilcox
Also move wake_up_locked() to be with the related functions Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-07-09sched: clean up sleep_on() APIsIngo Molnar
clean up the sleep_on() APIs: - do not use fastcall - replace fragile macro magic with proper inline functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-10-30[PATCH] lockdep: annotate DECLARE_WAIT_QUEUE_HEADPeter Zijlstra
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: [<c04051ed>] show_trace_log_lvl+0x58/0x16a kernel: [<c04057fa>] show_trace+0xd/0x10 kernel: [<c0405913>] dump_stack+0x19/0x1b kernel: [<c043b1e2>] __lock_acquire+0xf0/0x90d kernel: [<c043bf70>] lock_acquire+0x4b/0x6b kernel: [<c061472f>] _spin_lock_irqsave+0x22/0x32 kernel: [<c04363d3>] prepare_to_wait+0x17/0x4b kernel: [<f89a24b6>] lpfc_do_work+0xdd/0xcc2 [lpfc] kernel: [<c04361b9>] kthread+0xc3/0xf2 kernel: [<c0402005>] 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 <a.p.zijlstra@chello.nl> Cc: Greg KH <gregkh@suse.de> Cc: Markus Lidel <markus.lidel@shadowconnect.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@infradead.org> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] uninline init_waitqueue_head()Ingo Molnar
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 <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: annotate waitqueuesIngo Molnar
Create one lock class for all waitqueue locks in the kernel. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: locking init debugging improvementIngo Molnar
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 <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26Don't include linux/config.h from anywhere else in include/David Woodhouse
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-11-07[PATCH] fix remaining missing includesTim Schmielau
Fix more include file problems that surfaced since I submitted the previous fix-missing-includes.patch. This should now allow not to include sched.h from module.h, which is done by a followup patch. Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23[PATCH] aio: make wait_queue ->task ->privateBenjamin LaHaise
In the upcoming aio_down patch, it is useful to store a private data pointer in the kiocb's wait_queue. Since we provide our own wake up function and do not require the task_struct pointer, it makes sense to convert the task pointer into a generic private pointer. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-24[PATCH] Cleanup DEFINE_WAITblaisorblade@yahoo.it
Use LIST_HEAD_INIT rather than doing it by hand in DEFINE_WAIT. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!