On Fri, 2007-02-16 at 03:29 -0800, Dan Price wrote:
Yes, and it's done as long as you don't have mmap_disable=yes. Hmm. Weren't you using ZFS directly? Why are you using mmap_disable=yes? :) Its main purpose is to make indexes work in NFS.
Well there you go, I'm a dope. I think I set mmap_disable=yes because I was seeing strange things happening where there would be thousands (millions?) of madvise(DONTNEED) calls-- seemingly forever in a loop. I have not yet tracked that problem down-- next time I see it, I will make sure to get to the bottom of it.
Actually the only place where madvise(MADV_DONTNEED) is called is in the file-cache code which is used only with mmap_disable=yes.
There are madvise(MADV_SEQUENTIAL) calls with mmap_disable=no though.