On Tue, Oct 9, 2018 at 7:34 PM Luis Henriques <lhenriques@xxxxxxxx> wrote: > > Ilya Dryomov <idryomov@xxxxxxxxx> writes: > > > On Tue, Oct 9, 2018 at 12:47 PM Luis Henriques <lhenriques@xxxxxxxx> wrote: > >> > >> Hi, > >> > >> finally, here's a new iteration of my copy_file_range patchset. I've an > >> extra patch (not included in this RFC) that adds tracepoints to this > >> syscall. I wanted to know if that's something we would like to start > >> including in the kernel cephfs client. I can prepare a new rev that > >> includes this extra patch. > > > > No, if we start introducing tracepoints, it'll have to be throught > > libceph, rbd and ceph, replacing some of the douts. Tracepoints in > > some places and douts in other places is a no go. On top of that there > > is the whole tracepoint ABI stability mess, although it's less of an > > issue for individual filesystems... > > > > In any case it doesn't belong in this series. > > > > First of all, thanks a lot for your time reviewing this patchset. I've > skimmed through your comments and I believe they all make perfect > sense. I'll go through all of them and prepare a new revision in the > next few days. I only looked at net/ceph part. > > [ I still need to revisit those Op flags as I don't understand why I > assumed they would both be using CEPH_OSD_OP_FLAG_FADVISE_*. I > thought I saw a similar usage in the ceph code, but a quick grep > didn't show anything. ] > > Regarding tracepoints, I agree that having both dynamic debug (dout) and > tracepoints isn't a great idea. My preference would be to move to > tracepoints but it would take a while to visit all the douts and come up > with a set of patches that would convert the relevant ones to > tracepoints (I'm sure there would be a lot of douts that could actually > be dropped). > > Anyway, do you think it's worth opening a feature request so that some > day this could be done? Or would you rather continue using dynamic > debugging only? There is an old ticket for this - http://tracker.ceph.com/issues/2374. With the addition of eBPF tracepoints became a lot more more useful, so I'm all for a carefully designed initial set of tracepoints. Thanks, Ilya
