Daniel Phillips wrote: > After untarring four kernel trees, number of locks hits a peak of 128K. > With 64K buckets the hash, a typical region of the table looks like: > > 3 0 3 6 1 2 2 1 2 6 1 0 1 2 1 0 0 3 1 2 2 3 1 2 5 3 2 2 1 0 3 1 > 1 1 3 5 2 2 1 0 2 3 3 1 3 0 5 2 2 3 0 2 1 3 1 2 4 2 0 2 5 1 4 3 > 5 3 3 3 3 1 4 1 2 1 2 6 2 1 3 0 2 2 2 8 1 2 2 2 3 1 0 1 3 2 1 1 > 1 2 2 2 2 3 2 0 2 2 2 5 2 3 2 1 1 2 6 6 1 2 2 4 2 0 3 0 3 3 3 0 > 2 2 1 1 2 3 2 0 2 3 3 1 3 3 3 1 4 2 8 3 2 2 2 4 3 0 1 2 3 4 2 0 > 3 1 0 1 2 2 3 1 4 2 1 1 3 3 4 3 3 3 4 2 1 4 2 1 5 2 1 3 1 2 3 2 > 1 0 1 5 3 2 1 2 3 0 1 1 2 3 4 4 4 1 3 1 4 3 2 2 4 4 1 3 1 0 0 1 > 3 1 1 3 0 3 0 1 1 1 1 1 3 4 4 2 4 3 4 2 3 3 0 3 4 2 1 5 4 1 3 1 > 1 0 1 0 1 4 1 2 1 4 2 0 2 2 5 2 1 1 1 2 3 6 4 5 5 1 1 2 3 1 5 1 > 3 0 1 0 3 3 2 0 2 1 2 1 0 4 3 2 1 0 1 0 2 7 1 3 2 1 1 2 4 1 3 1 > 2 2 3 1 3 3 1 2 0 2 1 3 1 2 0 4 4 1 2 1 2 3 3 6 0 5 2 1 1 0 3 0 > 1 0 2 0 4 3 2 1 0 0 2 0 1 4 2 4 5 1 0 1 3 2 2 1 1 3 2 3 0 2 1 1 > 3 0 0 0 2 5 3 1 0 2 0 1 0 0 2 0 4 2 1 2 4 3 0 1 2 4 1 3 0 0 1 4 > > A poor distribution as you already noticed[1]. [...] > [1] And this is our all-important dentry hash function. Oops.
Why do you say that? I don't think it is particularly bad. Your sample has an average of 2.06, and a standard deviation of 1.49 while a random assignment using glibc's random() here has a standard deviation of 1.44 I can't remember much stats, but I think that means in your sample of over 400, you're likely to find several instances of "6" and not unlikely to find some higher. Actually given that it is bound at zero and so not a normal distribution, that is likely to move results a bit further to the right [I'm sure there's a formula for that], which is pretty consistent with what you have, and you would hardly notice a difference using rand() -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com _______________________________________________ Ocfs2-devel mailing list [email protected] http://oss.oracle.com/mailman/listinfo/ocfs2-devel
