lkml.org 
[lkml]   [2008]   [Jun]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    SubjectRe: [Bug #10815] 2.6.26-rc4: RIP find_pid_ns+0x6b/0xa0
    On Sat, Jun 14, 2008 at 11:43:38PM +0400, Alexey Dobriyan wrote:
    > On Sat, Jun 14, 2008 at 11:12:12AM -0700, Paul E. McKenney wrote:
    > > On Sat, Jun 14, 2008 at 06:58:39PM +0400, Oleg Nesterov wrote:
    > > > On 06/14, Paul E. McKenney wrote:
    > > > >
    > > > > On Fri, Jun 13, 2008 at 04:52:55PM +0300, Adrian Bunk wrote:
    > > > > > On Sat, Jun 07, 2008 at 10:42:57PM +0200, Rafael J. Wysocki 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 2.6.25. Please verify if it still should be listed.
    > > > > > >
    > > > > > >
    > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=10815
    > > > > > > Subject : 2.6.26-rc4: RIP find_pid_ns+0x6b/0xa0
    > > > > > > Submitter : Alexey Dobriyan <adobriyan@gmail.com>
    > > > > > > Date : 2008-05-27 09:23 (12 days old)
    > > > > > > References : http://lkml.org/lkml/2008/5/27/9
    > > > > > > Handled-By : Oleg Nesterov <oleg@tv-sign.ru>
    > > > > > > Linus Torvalds <torvalds@linux-foundation.org>
    > > > > > > Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    > > > > > > Patch : http://lkml.org/lkml/2008/5/28/16
    > > > > >
    > > > > > What happened with this issue?
    > > > >
    > > > > The patch listed above works for me, passes rcutorture, &c. However,
    > > > > I never have been able to reproduce the original problem, so cannot say
    > > > > whether it qualifies as a fix.
    > > >
    > > > I doubt very much RCU was the reason of this problem.
    > >
    > > Although I very much appreciate your confidence in my code, it is new
    > > code, so therefore under suspicion.
    > >
    > > > Alexey, how did you trigger this problem?
    > >
    > > One of them involved running LTP while doing 170 kernel builds in
    > > parallel.
    >
    > My gut feeling is that find_pid_ns oops, __d_lookup oops and
    > __call_for_each_cic oops are the same bug.
    >
    > And rcutorture failures I've mentioned to Paul privately.

    Yep, running rcutorture in parallel with LTP, which didn't reproduce
    for me either.

    Did the patch at http://lkml.org/lkml/2008/5/28/16 help?

    > Oleg, debugging you've posted never triggered.
    >
    > kerneloops suggests that I'm alone. :-(

    Assuming that the above patch didn't help... As a desperation measure,
    I could suggest the following patch.

    Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    ---

    rcupreempt.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    diff -urpNa -X dontdiff linux-2.6.26-rc4/kernel/rcupreempt.c linux-2.6.26-rc4-alexey/kernel/rcupreempt.c
    --- linux-2.6.26-rc4/kernel/rcupreempt.c 2008-05-30 04:39:01.000000000 -0700
    +++ linux-2.6.26-rc4-alexey/kernel/rcupreempt.c 2008-06-14 20:24:53.000000000 -0700
    @@ -77,7 +77,7 @@
    *
    * GP in GP_STAGES stands for Grace Period ;)
    */
    -#define GP_STAGES 2
    +#define GP_STAGES 3
    struct rcu_data {
    spinlock_t lock; /* Protect rcu_data fields. */
    long completed; /* Number of last completed batch. */

    \
     
     \ /
      Last update: 2008-06-15 05:33    [W:0.026 / U:0.088 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site