On Thu, Mar 21, 2013 at 09:35:38AM -0700, Kent Overstreet wrote: > The aio code tries really hard to avoid having to deal with the completion > ringbuffer overflowing. To do that, it has to keep track of the number of > outstanding kiocbs, and the number of completions currently in the > ringbuffer - and it's got to check that every time we allocate a kiocb. > Ouch. > > But - we can improve this quite a bit if we just change reqs_active to > mean "number of outstanding requests and unreaped completions" - that > means kiocb allocation doesn't have to look at the ringbuffer, which is a > fairly significant win.
Signed-off-by: "Theodore Ts'o" <[email protected]> Could you please add a quick comment documenting the reqs_active field in the struct kioctx definition here? For future code maintainability, it should be documented in fs/aio.c, not just in a commit description. > struct kioctx { > atomic_t users; > atomic_t dead; > @@ -92,7 +86,13 @@ struct kioctx { > atomic_t reqs_active; > struct list_head active_reqs; /* used for cancellation */ - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
