Support for mds stats

[Raphael Druon]

mds.MDS.mdt.stats:

mds.MDS.mdt.stats=
snapshot_time             1688128383.546447404 secs.nsecs
req_waittime              134066237 samples [usec] 2 223783 2088082648 471534475048
req_qdepth                134066237 samples [reqs] 0 33 360860 426556
req_active                134066237 samples [reqs] 1 82 174309144 308295414
req_timeout               134066237 samples [sec] 1 15 2010993249 30164896809
reqbuf_avail              274307261 samples [bufs] 61 64 17553178393 1123246805789
ldlm_ibits_enqueue        81452437 samples [reqs] 1 1 81452437 81452437
mds_reint_setattr         4377 samples [reqs] 1 1 4377 4377
mds_reint_create          17987068 samples [reqs] 1 1 17987068 17987068
mds_reint_unlink          34215148 samples [reqs] 1 1 34215148 34215148
mds_reint_open            33128857 samples [reqs] 1 1 33128857 33128857
ost_set_info              345 samples [usec] 7 50 7294 180944
mds_connect               73 samples [usec] 7 20470 30960 436899558
mds_disconnect            27 samples [usec] 39 393 5412 1514890
mds_get_root              28 samples [usec] 5 23 284 3574
mds_statfs                270 samples [usec] 6 52 5142 115274
mds_sync                  18256 samples [usec] 5 721 367130 11121902
obd_ping                  388208 samples [usec] 2 47039 6770169 21323667737

mds.MDS.mdt_readpage.stats:

mds.MDS.mdt_readpage.stats=
snapshot_time             1688128401.905932373 secs.nsecs
req_waittime              33128745 samples [usec] 2 35496 511938509 27521514737
req_qdepth                33128745 samples [reqs] 0 6 58069 63753
req_active                33128745 samples [reqs] 1 6 36206011 43141697
req_timeout               33128745 samples [sec] 15 15 496931175 7453967625
reqbuf_avail              67052468 samples [bufs] 61 64 4278031539 272954462355
mds_getattr               28 samples [usec] 26 58 949 33583
mds_close                 33128667 samples [usec] 8 130142 611180236 143780158340
mds_readpage              50 samples [usec] 118 1601 14411 6161215