On Thursday, March 22, 2012 1:48:29 pm Mark Saad wrote: > On Thu, Mar 22, 2012 at 8:03 AM, John Baldwin <j...@freebsd.org> wrote: > > On Wednesday, March 21, 2012 4:20:17 pm Mark Saad wrote: > >> On Wed, Mar 21, 2012 at 12:39 PM, Sergey Kandaurov <pluk...@gmail.com> > >> wrote: > >> > On 21 March 2012 19:19, John Baldwin <j...@freebsd.org> wrote: > >> >> 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. > >> > > >> > Yep, and since switching to direct map (somewhere around 7.x on amd64?) > >> > made PV entry limit factually obsolete, this is really cool. > >> > > >> > -- > >> > wbr, > >> > pluknet > >> > >> Interesting so this warning is relevant in 7.x ? > > > > No, looks like it was obsolete starting with 7.0. > > > > -- > > John Baldwin > > Any chance it could be mfc'ed to 7-STABLE ?
I just merged it to stable/7. -- 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"
