On Wed, Mar 28, 2007 at 05:48:10PM +0200, Wagner Ferenc wrote: > Ferenc Wagner <wferi@xxxxxxx> writes: > > > There's a good bunch of RRDs in a directory. A script scans them for > > their last modification times, and then updates each in turn for a > > couple of times. The number of files scanned and the length of the > > update rounds are printed. The results are much different for 500 and > > 501 files: > > > > filecount=501 > > iteration=0 elapsed time=10.425568 s > > iteration=1 elapsed time= 9.766178 s > > iteration=2 elapsed time=20.14514 s > > iteration=3 elapsed time= 2.991397 s > > iteration=4 elapsed time=20.496422 s > > total elapsed time=63.824705 s > > > > filecount=500 > > iteration=0 elapsed time=6.560811 s > > iteration=1 elapsed time=0.229375 s > > iteration=2 elapsed time=0.202973 s > > iteration=3 elapsed time=0.203439 s > > iteration=4 elapsed time=0.203095 s > > total elapsed time=7.399693 s > > Following up to myself with one more data point: raising > SHRINK_CACHE_MAX from 1000 to 20000 in gfs/dlm/lock_dlm.h helps > significantly, but still isn't enough. Besides, I don't know what I'm > doing. Should I tweak the surrounding #defines, too? SHRINK_CACHE_MAX is related to fcntl posix locks, did you intend to change the app to use flock (which is much faster that fcntl)? Dave -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
