I agree with Greg. When dealing with the latencies that we deal with due to different IO operations (networking, storage), it's mostly not worth the trouble. I think the main reason we didn't actually put it to use is that we forgot we've had this macro defined, and it really wasn't worth the trouble. I do think though that we can keep it in mind, and when developing add these notations when appropriate even if only for code readability. Thanks, Yehuda On Mon, Sep 15, 2014 at 9:39 AM, Gregory Farnum <greg at inktank.com> wrote: > I don't know where the file came from, but likely/unlikely markers are the > kind of micro-optimization that isn't worth the cost in Ceph dev resources > right now. > -Greg > > > On Monday, September 15, 2014, Tim Zhang <cofol1986 at gmail.com> wrote: > >> Hey guys, >> After reading ceph source code, I find that there is a file named >> common/likely.h and it implements the function likely() and unlikey() which >> will optimize the prediction of code branch for cpu. >> But there isn't any place using these two functions, I am curious >> about why the developer of ceph not using these two functions to achieve >> more performance. Can anyone provide some hints? >> BR >> > > > -- > Software Engineer #42 @ http://inktank.com | http://ceph.com > > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140915/02770887/attachment-0001.htm>
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