On Tue, 2021-10-26 at 11:05 +0800, Xiubo Li wrote: > On 10/22/21 1:30 AM, Patrick Donnelly wrote: > > On Thu, Oct 21, 2021 at 12:35 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > On Thu, 2021-10-21 at 12:18 -0400, Patrick Donnelly wrote: > > > > On Thu, Oct 21, 2021 at 11:44 AM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > > > On Thu, 2021-10-21 at 09:52 -0400, Patrick Donnelly wrote: > > > > > > On Wed, Oct 20, 2021 at 12:27 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > > > > > On Wed, 2021-10-20 at 15:37 +0100, Luís Henriques wrote: > > > > > > > > This counter will keep track of the number of remote object copies done on > > > > > > > > copy_file_range syscalls. This counter will be filesystem per-client, and > > > > > > > > can be accessed from the client debugfs directory. > > > > > > > > > > > > > > > > Cc: Patrick Donnelly <pdonnell@xxxxxxxxxx> > > > > > > > > Signed-off-by: Luís Henriques <lhenriques@xxxxxxx> > > > > > > > > --- > > > > > > > > This is an RFC to reply to Patrick's request in [0]. Note that I'm not > > > > > > > > 100% sure about the usefulness of this patch, or if this is the best way > > > > > > > > to provide the functionality Patrick requested. Anyway, this is just to > > > > > > > > get some feedback, hence the RFC. > > > > > > > > > > > > > > > > Cheers, > > > > > > > > -- > > > > > > > > Luís > > > > > > > > > > > > > > > > [0] https://github.com/ceph/ceph/pull/42720 > > > > > > > > > > > > > > > I think this would be better integrated into the stats infrastructure. > > > > > > > > > > > > > > Maybe you could add a new set of "copy" stats to struct > > > > > > > ceph_client_metric that tracks the total copy operations done, their > > > > > > > size and latency (similar to read and write ops)? > > > > > > I think it's a good idea to integrate this into "stats" but I think a > > > > > > local debugfs file for some counters is still useful. The "stats" > > > > > > module is immature at this time and I'd rather not build any qa tests > > > > > > (yet) that rely on it. > > > > > > > > > > > > Can we generalize this patch-set to a file named "op_counters" or > > > > > > similar and additionally add other OSD ops performed by the kclient? > > > > > > > > > > > > > > > > Tracking this sort of thing is the main purpose of the stats code. I'm > > > > > really not keen on adding a whole separate set of files for reporting > > > > > this. > > > > Maybe I'm confused. Is there some "file" which is already used for > > > > this type of debugging information? Or do you mean the code for > > > > sending stats to the MDS to support cephfs-top? > > > > > > > > > What's the specific problem with relying on the data in debugfs > > > > > "metrics" file? > > > > Maybe no problem? I wasn't aware of a "metrics" file. > > > > > > > Yes. For instance: > > > > > > # cat /sys/kernel/debug/ceph/*/metrics > > > item total > > > ------------------------------------------ > > > opened files / total inodes 0 / 4 > > > pinned i_caps / total inodes 5 / 4 > > > opened inodes / total inodes 0 / 4 > > > > > > item total avg_lat(us) min_lat(us) max_lat(us) stdev(us) > > > ----------------------------------------------------------------------------------- > > > read 0 0 0 0 0 > > > write 5 914013 824797 1092343 103476 > > > metadata 79 12856 1572 114572 13262 > > > > > > item total avg_sz(bytes) min_sz(bytes) max_sz(bytes) total_sz(bytes) > > > ---------------------------------------------------------------------------------------- > > > read 0 0 0 0 0 > > > write 5 4194304 4194304 4194304 20971520 > > > > > > item total miss hit > > > ------------------------------------------------- > > > d_lease 11 0 29 > > > caps 5 68 10702 > > > > > > > > > I'm proposing that Luis add new lines for "copy" to go along with the > > > "read" and "write" ones. The "total" counter should give you a count of > > > the number of operations. > > Okay that makes more sense! > > > > Side note: I am a bit horrified by how computer-unfriendly that > > table-formatted data is. > > Any suggestion to improve this ? > > How about just make the "metric" file writable like a switch ? And as > default it will show the data as above and if tools want the > computer-friendly format, just write none-zero to it, then show raw data > just like: > > # cat /sys/kernel/debug/ceph/*/metrics > opened_files:0 > pinned_i_caps:5 > opened_inodes:0 > total_inodes:4 > > read_latency:0,0,0,0,0 > write_latency:5,914013,824797,1092343,103476 > metadata_latency:79,12856,1572,114572,13262 > > read_size:0,0,0,0,0 > write_size:5,4194304,4194304,4194304,20971520 > > d_lease:11,0,29 > caps:5,68,10702 > > I'd rather not multiplex the output of this file based on some input. That would also be rather hard to do -- write() and read() are two different syscalls, so you'd need to track a bool (or something) across them somehow. Currently, I doubt there are many scripts in the field that scrape this info and debugfs is specifically excluded from ABI concerns. If we want to make it more machine-readable (which sounds like a good thing), then I suggest we just change the output to something like what you have above and not worry about preserving the "legacy" output. -- Jeff Layton <jlayton@xxxxxxxxxx>
