Messages in this thread | | | Date | Thu, 12 Mar 2009 06:39:16 -0700 (PDT) | From | Davide Libenzi <> | Subject | Re: [PATCH] fs: fput() can be called from interrupt context |
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On Wed, 11 Mar 2009, Andrew Morton wrote:
> > Take the time to check how fs/aio.c handle the fput(req->ki_filp) case > > (or read my 2nd patch, it should spot the thing) > > Well yes, a kludge like that seems a bit safer. > > It's somewhat encouraging that we're apparently already doing fput() > from within keventd (although how frequently?). There might be > problems with file locking, security code, etc from doing fput() from > an unexpected thread. And then there are all the usual weird problem > with using the keventd queues which take a long time to get discovered.
Would it be a huge problem, performance-wise, to stop making ->f_count tricks in __aio_put_req, and always offload to fput_work the task of releasing the requests? If that's a huge problem, IMO the lower impact fix would be to use aio_fput_routine to loop into a second list, releasing the eventual eventfd file*. There's no need, IMO, to turn the whole fput() into IRQ-callable just for this case, when we can contain it into the particular KAIO+eventfd usage.
- Davide
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