Re: Soft lockups during reading /proc/PID/smaps

2014-08-04 Thread Oleg Nesterov
On 08/03, Aleksei Besogonov wrote: > > Thanks, it works on the rc7 kernel. Great! I didn't have time today, will write the changelog and send the patch tomorrow. Thanks a lot Aleksei. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to

Re: Soft lockups during reading /proc/PID/smaps

2014-08-04 Thread Oleg Nesterov
On 08/03, Aleksei Besogonov wrote: Thanks, it works on the rc7 kernel. Great! I didn't have time today, will write the changelog and send the patch tomorrow. Thanks a lot Aleksei. Oleg. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to

Re: Soft lockups during reading /proc/PID/smaps

2014-08-03 Thread Aleksei Besogonov
On 02 Aug 2014, at 11:19, Oleg Nesterov wrote: > On 07/31, Aleksei Besogonov wrote: >> >> On 31 Jul 2014, at 00:43, David Rientjes wrote: >> >>> The while_each_thread() in vm_is_stack() looks suspicious since the task >>> isn't current and rcu won't protect the iteration, and we also don't

Re: Soft lockups during reading /proc/PID/smaps

2014-08-03 Thread Aleksei Besogonov
On 02 Aug 2014, at 11:19, Oleg Nesterov o...@redhat.com wrote: On 07/31, Aleksei Besogonov wrote: On 31 Jul 2014, at 00:43, David Rientjes rient...@google.com wrote: The while_each_thread() in vm_is_stack() looks suspicious since the task isn't current and rcu won't protect the iteration,

Re: Soft lockups during reading /proc/PID/smaps

2014-08-02 Thread Oleg Nesterov
On 07/31, Aleksei Besogonov wrote: > > On 31 Jul 2014, at 00:43, David Rientjes wrote: > > > The while_each_thread() in vm_is_stack() looks suspicious since the task > > isn't current and rcu won't protect the iteration, and we also don't hold > > sighand lock or a readlock on tasklist_lock. > >

Re: Soft lockups during reading /proc/PID/smaps

2014-08-02 Thread Oleg Nesterov
On 07/31, Aleksei Besogonov wrote: On 31 Jul 2014, at 00:43, David Rientjes rient...@google.com wrote: The while_each_thread() in vm_is_stack() looks suspicious since the task isn't current and rcu won't protect the iteration, and we also don't hold sighand lock or a readlock on

Re: Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread Aleksei Besogonov
On 31 Jul 2014, at 00:43, David Rientjes wrote: > On Thu, 31 Jul 2014, Aleksei Besogonov wrote: >> I'm getting weird soft lockups while reading smaps on loaded systems with >> some background cgroups usage. This issue can be reproduced with the most >> recent kernel. >> >> Here's the stack

Re: Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread David Rientjes
On Thu, 31 Jul 2014, Aleksei Besogonov wrote: > I'm getting weird soft lockups while reading smaps on loaded systems with > some background cgroups usage. This issue can be reproduced with the most > recent kernel. > > Here's the stack trace: > [ 1748.312052] BUG: soft lockup - CPU#6 stuck for

Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread Aleksei Besogonov
I'm getting weird soft lockups while reading smaps on loaded systems with some background cgroups usage. This issue can be reproduced with the most recent kernel. Here's the stack trace: [ 1748.312052] BUG: soft lockup - CPU#6 stuck for 23s! [python2.7:1857] [ 1748.312052] Modules linked in: xfs

Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread Aleksei Besogonov
I'm getting weird soft lockups while reading smaps on loaded systems with some background cgroups usage. This issue can be reproduced with the most recent kernel. Here's the stack trace: [ 1748.312052] BUG: soft lockup - CPU#6 stuck for 23s! [python2.7:1857] [ 1748.312052] Modules linked in: xfs

Re: Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread David Rientjes
On Thu, 31 Jul 2014, Aleksei Besogonov wrote: I'm getting weird soft lockups while reading smaps on loaded systems with some background cgroups usage. This issue can be reproduced with the most recent kernel. Here's the stack trace: [ 1748.312052] BUG: soft lockup - CPU#6 stuck for 23s!

Re: Soft lockups during reading /proc/PID/smaps

2014-07-31 Thread Aleksei Besogonov
On 31 Jul 2014, at 00:43, David Rientjes rient...@google.com wrote: On Thu, 31 Jul 2014, Aleksei Besogonov wrote: I'm getting weird soft lockups while reading smaps on loaded systems with some background cgroups usage. This issue can be reproduced with the most recent kernel. Here's the