On Thu, Jun 25, 2009 at 11:16:50AM -0700, Sean Liu wrote: > > Now that ZFS cache will eat up all the free mem for cache, again > > that's all fine. But vmstat doesn't report meaningful free memory > > again. Yes memstat can tell you the ZFS file data size but who wants > > to run mdb every now and then? > > > > Can we introduce some new kernel variable the way we introduced > > cachelist and make vmstat free memory report meaningful again?
johan...@sun.com replied > I disagree with the premise that the free memory calculation isn't > useful because it doesn't count ZFS caches as free space. [big snip] > The space that's consumed by ZFS is in use and can't simply be peeled > off a free-list and used immediately. Adding a variable that counts > space used by ZFS as free is actually going to be more confusing. I worry that we're making a silent change to "all memory is considered used" again. If we are, we will have to kludge up a metric, like scan rate that spiked when we run out of memory. I used to be on the ABI (stability) team and my boss would happily fricassee me if I proposed that (;-)) --dave -- David Collier-Brown | Always do right. This will gratify Sun Microsystems, Toronto | some people and astonish the rest dav...@sun.com | -- Mark Twain cell: (647) 833-9377, home (416) 223-8968, bridge (877) 385-4099 code 506 9191# _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
