|Summary:||TREE_RCU hangs at boot|
|Product:||Platform Specific/Hardware||Reporter:||Rolf Eike Beer (eike-kernel)|
|Component:||PA-RISC||Assignee:||Paul E. McKenney (paulmck)|
|Bug Depends on:|
|Attachments:||Config of 22.214.171.124|
Description Rolf Eike Beer 2010-08-07 12:18:40 UTC
I upgraded my C3600 from 126.96.36.199 to 2.6.35 and now it hangs on boot. If I switch to TINY_RCU it works again.
Comment 1 Andrew Morton 2010-08-25 23:57:22 UTC
Reassigned to Paul. Is this a regression? Sounds like it.
Comment 2 Paul E. McKenney 2010-08-26 00:43:45 UTC
Hello, Rolf! Could you please post the offending .config and console log? If the log is a silent hang, could you please force stack traces from sysrq or whatever you have handy?
Comment 3 Rolf Eike Beer 2010-08-26 06:12:22 UTC
Created attachment 28001 [details] Config of 188.8.131.52 Used that config for 2.6.35 with "make oldconfig".
Comment 4 Paul E. McKenney 2010-08-26 15:17:41 UTC
Thank you for the info, Rolf! Could you please set CONFIG_RCU_CPU_STALL_DETECTOR=y and try again? This diagnostic config option might print valuable information to the console. (Of course, the console log from your previous hang would be very useful -- just knowing roughly where in the boot process the hang occurred would help me.)
Comment 5 Rolf Eike Beer 2010-08-28 07:38:53 UTC
Sorry, I had no time to try this yesterday. I'll be on vacation for the next 2 weeks. Before I ran into this the issue was already known in #gentoo-hppa on Freenode IRC. Maybe you could ask for some tests there, the guys there also have affected machines at hand.
Comment 6 Paul E. McKenney 2010-08-30 14:29:29 UTC
Thank you, Rolf -- I pointed that IRC channel to this bug.
Comment 7 Rafael J. Wysocki 2010-08-30 17:36:55 UTC
On Monday, August 30, 2010, Rolf Eike Beer wrote: > Rafael J. Wysocki wrote: > > This message has been generated automatically as a part of a report > > of regressions introduced between 2.6.34 and 2.6.35. > > > > The following bug entry is on the current list of known regressions > > introduced between 2.6.34 and 2.6.35. Please verify if it still should > > be listed and let the tracking team know (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=16537 > > Subject : TREE_RCU hangs at boot > > Submitter : Rolf Eike Beer <email@example.com> > > Date : 2010-08-07 12:18 (23 days old) > > Yes, this is a regression that is still unfixed.
Comment 8 Rafael J. Wysocki 2010-09-12 18:49:26 UTC
Handled-By : Paul E. McKenney <firstname.lastname@example.org>
Comment 9 Rafael J. Wysocki 2010-09-21 19:07:06 UTC
On Tuesday, September 21, 2010, Paul E. McKenney wrote: > On Mon, Sep 20, 2010 at 11:26:27AM -0700, Paul E. McKenney wrote: > > On Sun, Sep 12, 2010 at 09:08:42PM +0200, Rafael J. Wysocki wrote: > > > This message has been generated automatically as a part of a report > > > of regressions introduced between 2.6.34 and 2.6.35. > > > > > > The following bug entry is on the current list of known regressions > > > introduced between 2.6.34 and 2.6.35. Please verify if it still should > > > be listed and let the tracking team know (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=16537 > > > Subject : TREE_RCU hangs at boot > > > Submitter : Rolf Eike Beer <email@example.com> > > > Date : 2010-08-07 12:18 (37 days old) > > > Handled-By : Paul E. McKenney <firstname.lastname@example.org> > > > > I cannot reproduce this. The function that is claimed to hang contains > > only printk()s. I have asked the guys who can actually reproduce it > > to try a later kernel, and will let you know how this goes. > > > > If you cannot trust printk(), who can you trust? ;-) > > It turns out that this problem is due to tab processing in the PA-RISC > firmware, which certainly explains my inability to reproduce it. It > turns out that it is fixed by: > > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=d9b68e5e88248bb24fd4e455588bea1d56108fd6 > > So we can close this regression. > > Many thanks to Guy Martin <email@example.com> for much help with > this!!!