Messages in this thread | | | Date | Fri, 22 Jun 2018 14:33:07 +0200 | From | Christoph Hellwig <> | Subject | Re: [lkp-robot] [fs] 3deb642f0d: will-it-scale.per_process_ops -8.8% regression |
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On Fri, Jun 22, 2018 at 01:17:22PM +0100, Al Viro wrote: > > The problem is that call to sk_busy_loop(), which is going to be indirect > > no matter what. > > if ->f_poll_head is NULL { > use ->poll > } else { > if can ll_poll (checked in ->f_mode) > call ->ll_poll(), if it returns what we want - we are done > add to ->f_poll_head > call ->poll_mask()
What I have for now is slightly different:
if ((events & POLL_BUSY_LOOP) && file->f_op->poll_busy_loop) file->f_op->poll_busy_loop(file, events);
if (file->f_op->poll) { return file->f_op->poll(file, pt); } else if (file_has_poll_mask(file)) { ... }
returns whatever we want part is something I want to look into once the basics are done as it probably is non entirely trivial due to structure of polling in the low-level network protocol.
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