Messages in this thread | | | Date | Sun, 14 Dec 2014 03:14:29 +0000 | From | Al Viro <> | Subject | Re: frequent lockups in 3.18rc4 |
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On Sat, Dec 13, 2014 at 05:35:17PM -0800, Linus Torvalds wrote: > On Sat, Dec 13, 2014 at 4:33 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > > > > So does SMP - this_cpu_dec() relies on preemption being disabled. > > No. really. It very much does not. Not on x86, not elsewhere. It's > part of the whole point of "this_cpu_p()". They are preemption and > interrupt safe. > > It's the "__this_cpu_op()" ones that need external protection.
Right you are - I really need to get some coffee... Sorry...
FWIW, do we need to disable interrupts there? After all, mnt_want_write() and mnt_drop_write() shouldn't be done from interrupt context - they can happen via schedule_delayed_work(), but that's it...
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