Re: svn commit: r215791 - stable/8/sys/netinet
On Wed, Nov 24, 2010 at 06:11:53PM +1100, Bruce Evans wrote: B +++ stable/8/sys/netinet/if_ether.cWed Nov 24 05:37:12 2010 (r215791) B @@ -381,7 +381,7 @@ retry: B int canceled; B B LLE_ADDREF(la); B - la-la_expire = time_second + V_arpt_down; B + la-la_expire = time_second; B canceled = callout_reset(la-la_timer, hz * V_arpt_down, B arptimer, la); B if (canceled) B B B Isn't using non-monotic time for timeouts always wrong? Sure it is wrong. I never payed attention to that fact that time_second could be non-monotic. Is it non-monotic? I failed to understand kern_tc code at first glance. B There are lots of other time_second's in networkining code. These B still outnumber time_uptime's by about 68:41. rtcock.c uses the weird B expression time_second - time_uptime for metrics. Since time_uptime B is relative to boot time while time_second is relative to the Epoch, B their difference is approximately the number of seconds since the B Epoch, which is a very strange value which might nevertheless be B useful for converting between monotonic expiry times and real expiry B times, but I think it doesn't work even for that if the real time is B stepped. B B Bruce -- Totus tuus, Glebius. ___ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to svn-src-all-unsubscr...@freebsd.org
Re: svn commit: r215791 - stable/8/sys/netinet
On Wed, 24 Nov 2010, Gleb Smirnoff wrote: On Wed, Nov 24, 2010 at 06:11:53PM +1100, Bruce Evans wrote: B +++ stable/8/sys/netinet/if_ether.c Wed Nov 24 05:37:12 2010 (r215791) B @@ -381,7 +381,7 @@ retry: B int canceled; B B LLE_ADDREF(la); B -la-la_expire = time_second + V_arpt_down; B +la-la_expire = time_second; B canceled = callout_reset(la-la_timer, hz * V_arpt_down, B arptimer, la); B if (canceled) B B B Isn't using non-monotic time for timeouts always wrong? monotonic Sure it is wrong. I never payed attention to that fact that time_second could be non-monotic. Is it non-monotic? I failed to understand kern_tc code at first glance. Real time (time_second) can go backwards (or jump forwards too much) if someone steps the the clock. In kern_tc.c, time_uptime is implemented as a purely monotonic clock which goes forward by 1 (second) approximately every 1 second of real-real-time, while time_second is misimplemented as essentially (boottime.tv_sec + time_uptime), where boottime is bogusly changed (although the actual boot time didn't change) if someone steps the realtime clock to fix drift in it, including for POSIX leap seconds and resumes. (Suspends stop the monotonic clock, and on resume only the real time clock is advanced by much (by bogusly setting boottime forwards so that (boottime.tv_sec + time_uptime) gives the correct real time.) Using real time is actually correct for some timeouts, mainly for long ones. E.g., ones for the next day shouldn't be 8 hours late because the system was suspended overnight. Bruce ___ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to svn-src-all-unsubscr...@freebsd.org
svn commit: r215791 - stable/8/sys/netinet
Author: glebius Date: Wed Nov 24 05:37:12 2010 New Revision: 215791 URL: http://svn.freebsd.org/changeset/base/215791 Log: MFhead r214508: Revert a small part of the r198301, that is entirely unrelated to the r198301 itself. It also broke the logic of not sending more than one ARP request per second, that consequently lead to a potential problem of flooding network with broadcast packets. Modified: stable/8/sys/netinet/if_ether.c Modified: stable/8/sys/netinet/if_ether.c == --- stable/8/sys/netinet/if_ether.c Wed Nov 24 05:24:36 2010 (r215790) +++ stable/8/sys/netinet/if_ether.c Wed Nov 24 05:37:12 2010 (r215791) @@ -381,7 +381,7 @@ retry: int canceled; LLE_ADDREF(la); - la-la_expire = time_second + V_arpt_down; + la-la_expire = time_second; canceled = callout_reset(la-la_timer, hz * V_arpt_down, arptimer, la); if (canceled) ___ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to svn-src-all-unsubscr...@freebsd.org
Re: svn commit: r215791 - stable/8/sys/netinet
On Wed, 24 Nov 2010, Gleb Smirnoff wrote: Log: MFhead r214508: Revert a small part of the r198301, that is entirely unrelated to the r198301 itself. It also broke the logic of not sending more than one ARP request per second, that consequently lead to a potential problem of flooding network with broadcast packets. Modified: stable/8/sys/netinet/if_ether.c Modified: stable/8/sys/netinet/if_ether.c == --- stable/8/sys/netinet/if_ether.c Wed Nov 24 05:24:36 2010 (r215790) +++ stable/8/sys/netinet/if_ether.c Wed Nov 24 05:37:12 2010 (r215791) @@ -381,7 +381,7 @@ retry: int canceled; LLE_ADDREF(la); - la-la_expire = time_second + V_arpt_down; + la-la_expire = time_second; canceled = callout_reset(la-la_timer, hz * V_arpt_down, arptimer, la); if (canceled) Isn't using non-monotic time for timeouts always wrong? There are lots of other time_second's in networkining code. These still outnumber time_uptime's by about 68:41. rtcock.c uses the weird expression time_second - time_uptime for metrics. Since time_uptime is relative to boot time while time_second is relative to the Epoch, their difference is approximately the number of seconds since the Epoch, which is a very strange value which might nevertheless be useful for converting between monotonic expiry times and real expiry times, but I think it doesn't work even for that if the real time is stepped. Bruce ___ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to svn-src-all-unsubscr...@freebsd.org
