On Thu, Feb 05, 2015 at 12:45:55AM -0800, Alfred Perlstein wrote: > > > On 2/5/15 12:30 AM, Konstantin Belousov wrote: > > On Thu, Feb 05, 2015 at 08:56:59AM +0100, Dimitry Andric wrote: > >> If you let bsdtar continue, and press control-T a few times, does the > >> user time (u) increase at all? Does it ever go any further, if you let > >> it run for a very long time? > >> > >> I believe a problem may have been introduced by r277922, leading to > >> filesystem hangs in some scenarios. It looks like this commit is also > >> in dumbbell's github fork: > >> > >> https://github.com/dumbbell/freebsd/commit/83723416a6bb8695d60c6573722a81086899f521 > >> > > > > Would be nice if you mailed me with your findings. > > > > Please try this. > > > > diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c > > index 79783c8..700854e 100644 > > --- a/sys/ufs/ffs/ffs_softdep.c > > +++ b/sys/ufs/ffs/ffs_softdep.c > > @@ -1393,7 +1393,7 @@ softdep_flush(addr) > > VFSTOUFS(mp)->softdep_jblocks->jb_suspended)) > > kthread_suspend_check(); > > ACQUIRE_LOCK(ump); > > - while ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) > > + if ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) > > msleep(&ump->softdep_flushtd, LOCK_PTR(ump), PVM, > > "sdflush", hz / 2); > > ump->softdep_flags &= ~FLUSH_CLEANUP; > > @@ -1423,10 +1423,9 @@ worklist_speedup(mp) > > > > ump = VFSTOUFS(mp); > > LOCK_OWNED(ump); > > - if ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) { > > + if ((ump->softdep_flags & (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) > > ump->softdep_flags |= FLUSH_CLEANUP; > > - wakeup(&ump->softdep_flushtd); > > - } > > + wakeup(&ump->softdep_flushtd); > > } > > > > static int > > @@ -1471,11 +1470,10 @@ softdep_speedup(ump) > > TAILQ_INSERT_TAIL(&softdepmounts, sdp, sd_next); > > FREE_GBLLOCK(&lk); > > if ((altump->softdep_flags & > > - (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) { > > + (FLUSH_CLEANUP | FLUSH_EXIT)) == 0) > > altump->softdep_flags |= FLUSH_CLEANUP; > > - altump->um_softdep->sd_cleanups++; > > - wakeup(&altump->softdep_flushtd); > > - } > > + altump->um_softdep->sd_cleanups++; > > + wakeup(&altump->softdep_flushtd); > > FREE_LOCK(altump); > > } > > } > > _______________________________________________ > > Why the conversion of while() to if()? > > > The reason for a while() when doing msleep/wakeup is typically to > prevent superfluous wakeups from signalling early.
if()->while() was one of the changes in r277922, and I suspect that it is the cause of the issue. I.e. my thought right now is that softdep_process_worklist() does not keep up with the requests. If this is true, then real fix is somewhere else, but restoring pre-r277922 behaviour should get rid of immediate pain. _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
