On Tuesday, March 20, 2012 11:37:57 am Sergey Kandaurov wrote: > On 22 November 2011 19:29, Mark Saad <nones...@longcount.org> wrote: > > Hello All > > [found this mail in my drafts, not sure if my answer is still useful] > > > I want to get to the bottom of a warning in dmesg. On 7.2-RELEASE and > > 7.3-RELEASE I have seen the following warning in dmesg. > > > > Approaching the limit on PV entries, consider increasing either the > > vm.pmap.shpgperproc or the vm.pmap.pv_entry_max sysctl. > > > > So looking around I see a few posts here and there about how to tune > > the sysctls to address the warning however I am not 100% sure what > > each value does. > > It appears changing vm.pmap.shpgperproc affects the value of > > vm.pmap.pv_entry_max . Can someone explain the relationship of the two > > sysctls. Also > > This is how they are calculated. > > pv_entry_max = shpgperproc * maxproc + cnt.v_page_count; > > and, respectively, > > shpgperproc = (pv_entry_max - cnt.v_page_count) / maxproc; > > So, changing one sysctl will change another and vice versa. > > > what pitfalls of changing them are. > > Not known to me (on amd64 platform). > I have had vm.pmap.shpgperproc=15000 on 8.1 amd64 with 4G RAM > to make some badly written commercial software to work until it > was decommissioned to the scrap.
FYI, Alan just removed this warning and the associated sysctls from HEAD yesterday because they were made obsolete several years ago. I think they are obsolete even on 7. Certainly on 8. -- John Baldwin _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
