Various calls that downgrade permissions or virtually copy a pmap in pmap.c now remove PG_W (and did not 6 months ago). This may be the cause of the regression. It would probably be better (and faster) if the pages were "held" instead of wired.
-Kip On Nov 13, 2007 4:49 PM, Kris Kennaway <[EMAIL PROTECTED]> wrote: > Kip Macy wrote: > > Unfortunately, ZERO_COPY_SOCKETs have long been a known source of > > problems. I think also, when a page is copied as part of COW the new > > page is unwired (see pmap_copy et al.), this could lead to > > socow_iodone unwiring after send a page that was not wired. An added > > issue is that parts of the VM assume that COW and wired are mutually > > exclusive which the socow code violates. > > > > At some point in the near future I may be adding support for doing > > zero copy send without COW for blocking sockets. The one down side of > > this approach is that if you have multiple threads in your process it > > widens the window during which they can stomp on data that you're > > sending. Nonetheless, this would be a bug in the application code. > > More complicated would be zero-copy non-COW send on non-blocking > > sockets as it would require an extension to kevent for completion > > notification. > > > > In the meantime, your best bet is to disable ZERO_COPY_SOCKETS. > > There is a chance this was a recent regression, previously in 7.0 they > were believed to work. > > Kris > > > > > > > > -Kip > > > > > > > > On Nov 13, 2007 1:59 PM, Vivek Khera <[EMAIL PROTECTED]> wrote: > >> On Nov 13, 2007, at 4:50 PM, Vlad GALU wrote: > >> > >>>> vmio = 1 > >>>> offset = Unhandled dwarf expression opcode 0x93 > >>>> (kgdb) > >>>> > >>> Do you happen to have ZERO_COPY_SOCKETS in your kernel config? > >>> > >>> > >> Yes, I do. Are they known to be bad under certain loads or just in > >> general. I don't have this issue with any other web server running > >> the same kernel config but those are amd64 boxes mostly. > >> > >> > >> _______________________________________________ > >> freebsd-stable@freebsd.org mailing list > >> http://lists.freebsd.org/mailman/listinfo/freebsd-stable > >> To unsubscribe, send any mail to "[EMAIL PROTECTED]" > >> > > _______________________________________________ > > freebsd-stable@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > > To unsubscribe, send any mail to "[EMAIL PROTECTED]" > > > > > > _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"