Messages in this thread | | | Date | Thu, 19 Dec 2013 15:23:22 +1100 | From | Dave Chinner <> | Subject | Re: [fs] inode_lru_isolate(): Move counter increment into spinlock section |
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On Wed, Dec 18, 2013 at 07:24:46PM +0000, Christoph Lameter wrote: > The counter increment in inode_lru_isolate is happening after > spinlocks have been dropped with preemption on using __count_vm_events > making counter increment races possible.
That's a nasty, undocumented problem that __count_vm_events() has. Nobody who is modifying the fs/inode.c code is likely to know about this, so just moving the code under an unrelated lock is not sufficient to prevent this from happening again. Hence I'd prefer that you just change it to use count_vm_events() rather than try to be tricksy by replacing the landmine in the code that we've already stepped on once.
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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