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Revert "workqueue: allow work_on_cpu() to be called recursively"

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This reverts commit c2fda50966.

c2fda50966 removed lockdep annotation from work_on_cpu() to work around
the PCI path that calls work_on_cpu() from within a work_on_cpu() work item
(PF driver .probe() method -> pci_enable_sriov() -> add VFs -> VF driver
.probe method).

961da7fb6b22 ("PCI: Avoid unnecessary CPU switch when calling driver
.probe() method) avoids that recursive work_on_cpu() use in a different
way, so this revert restores the work_on_cpu() lockdep annotation.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Bjorn Helgaas 2013-11-18 11:00:29 -07:00
parent 12c3156f10
commit 12997d1a99
1 changed files with 10 additions and 22 deletions
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32
kernel/workqueue.c
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@ -2840,19 +2840,6 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr)
return false;
}
static bool __flush_work(struct work_struct *work)
{
struct wq_barrier barr;
if (start_flush_work(work, &barr)) {
wait_for_completion(&barr.done);
destroy_work_on_stack(&barr.work);
return true;
} else {
return false;
}
}
/**
* flush_work - wait for a work to finish executing the last queueing instance
* @work: the work to flush
@ -2866,10 +2853,18 @@ static bool __flush_work(struct work_struct *work)
*/
bool flush_work(struct work_struct *work)
{
struct wq_barrier barr;
lock_map_acquire(&work->lockdep_map);
lock_map_release(&work->lockdep_map);
return __flush_work(work);
if (start_flush_work(work, &barr)) {
wait_for_completion(&barr.done);
destroy_work_on_stack(&barr.work);
return true;
} else {
return false;
}
}
EXPORT_SYMBOL_GPL(flush_work);
@ -4814,14 +4809,7 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
schedule_work_on(cpu, &wfc.work);
/*
* The work item is on-stack and can't lead to deadlock through
* flushing. Use __flush_work() to avoid spurious lockdep warnings
* when work_on_cpu()s are nested.
*/
__flush_work(&wfc.work);
flush_work(&wfc.work);
return wfc.ret;
}
EXPORT_SYMBOL_GPL(work_on_cpu);