Messages in this thread | | | Date | Tue, 18 Mar 2014 17:23:19 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH RFC] sched: introduce add_wait_queue_exclusive_head |
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On 03/18, Peng Tao wrote: > > On Tue, Mar 18, 2014 at 10:05 PM, Peter Zijlstra <peterz@infradead.org> wrote: > > > > Unless you cannot use ___wait() and really need to open-code the > > wait_event() stuff. > > > Lustre's private l_wait_event() stuff takes care to (un)mask > LUSTRE_FATAL_SIGS
Hmm. This is off-topic but after the quick grep LUSTRE_FATAL_SIGS/etc looks suspicious.
Firtsly, cfs_block_sigs/cfs_block_sigsinv/etc are not exactly right, they need set_current_blocked(). And you can read "old" lockless.
And note that cfs_block_sigsinv(0) (which should block all signals) can't actually protect from SIGKILL (or in fact from another fatal signal) or SIGSTOP if the caller is multithreaded. Or ptrace, or freezer.
> and always wait in TASK_INTERRUPTIBLE state.
and it seems that __wstate passed to waitq_wait/waitq_timedwait is simply ignored.
> It looks to me that we can at least wrap l_wait_event() on top of > wait_event_interruptible/wait_event_timeout_interruptible.
l_wait_event looks really complicated ;) but perhaps you can rewrite it on top of ___wait_event(), note that condition/cmd can do anything you want.
Oleg.
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