On Saturday, 13 of December 2008, Fabio Comolli wrote: > Hi. Hi, > On Sat, Dec 13, 2008 at 5:33 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > This message has been generated automatically as a part of a report > > of recent regressions. > > > > The following bug entry is on the current list of known regressions > > from 2.6.27. Please verify if it still should be listed and let me know > > (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12155 > > Subject : Regression in 2.6.28-rc and 2.6.27-stable - hibernate related > > Submitter : Fabio Comolli <fabio.comolli@xxxxxxxxx> > > Date : 2008-11-23 16:17 (21 days old) > > References : http://marc.info/?l=linux-kernel&m=122745709926361&w=4 > > Still present. It has been bisected to: > > --------------------------------------------------------------------------------------------------------------- > commit 5e55aa8db085dad1aabb4574c73c23c7ae571e7b > Author: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx> > Date: Sun Oct 26 18:20:14 2008 -0400 > > sched_clock: prevent scd->clock from moving backwards > > commit 5b7dba4ff834259a5623e03a565748704a8fe449 upstream > > sched_clock: prevent scd->clock from moving backwards > > When sched_clock_cpu() couples the clocks between two cpus, it may > increment scd->clock beyond the GTOD tick window that __update_sched_clock() > uses to clamp the clock. A later call to __update_sched_clock() may move > the clock back to scd->tick_gtod + TICK_NSEC, violating the clock's > monotonic property. > > This patch ensures that scd->clock will not be set backward. > > Signed-off-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx> > Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> > Signed-off-by: Ingo Molnar <mingo@xxxxxxx> > Cc: Chuck Ebbert <cebbert@xxxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> > ------------------------------------------------------------------------------------------------------------ > > Both 2.6.27.8 and 2.6.28-rc8 with that commit reverted work fine > (well, at least they failed to show the bug so far). Thanks for the update, I have put this information into the Bugzilla entry. Would everyone involved agree with reverting the above commit for now and revisiting the issue in the 2.6.29 time frame? Rafael -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
