Re: 2.6.25 regression: vivi - scheduling while atomic

[Andrew Morton <akpm@linux-foundation.org>]

> On Tue, 22 Apr 2008 02:08:32 +0200 hermann pitton <hermann-pitton@arcor.de> wrote:
> Hi,
> 
> Am Montag, den 21.04.2008, 15:37 -0700 schrieb Brandon Philips:
> > On 10:16 Mon 21 Apr 2008, Gregor Jasny wrote:
> > > Call Trace:
> > >  [<ffffffff803efc9b>] schedule+0xe5/0x5c7
> > >  [<ffffffff80251c90>] __rmqueue_smallest+0x88/0x107
> > >  [<ffffffff8023e84b>] getnstimeofday+0x2f/0x83
> > >  [<ffffffff8023cf8a>] ktime_get_ts+0x17/0x48
> > >  [<ffffffff803f0424>] schedule_timeout+0x1e/0xad
> > >  [<ffffffff80220498>] enqueue_task+0x13/0x1e
> > >  [<ffffffff803efab8>] wait_for_common+0xf6/0x16b
> > >  [<ffffffff802230a0>] default_wake_function+0x0/0xe
> > >  [<ffffffff8023a270>] kthread_create+0xa3/0x108
> > >  [<ffffffff880d2471>] :vivi:vivi_thread+0x0/0x779
> > >  [<ffffffff802634cb>] remap_vmalloc_range+0xa1/0xe6
> > >  [<ffffffff80231242>] lock_timer_base+0x26/0x4c
> > >  [<ffffffff8023138e>] __mod_timer+0xb6/0xc5
> > >  [<ffffffff880d23fc>] :vivi:vivi_start_thread+0x54/0xc9
> > >  [<ffffffff88053603>] :videobuf_core:videobuf_streamon+0x6c/0xaa
> > >  [<ffffffff8809dba3>] :videodev:__video_do_ioctl+0x1327/0x2ad9
> > >  [<ffffffff80222d76>] __wake_up+0x38/0x4f
> > >  [<ffffffff80242f1f>] futex_wake+0xdb/0xfa
> > >  [<ffffffff8809f6ab>] :videodev:video_ioctl2+0x17c/0x210
> > >  [<ffffffff8025bb36>] handle_mm_fault+0x6b1/0x6cb
> > >  [<ffffffff8027b47d>] vfs_ioctl+0x55/0x6b
> > >  [<ffffffff8027b6e6>] do_vfs_ioctl+0x253/0x264
> > >  [<ffffffff8027b733>] sys_ioctl+0x3c/0x5d
> > >  [<ffffffff8020afcb>] system_call_after_swapgs+0x7b/0x80
> > >
> > > This happenes on a vanilla 2.6.25 with loaded nvidia graphics module.
> > > System architecture is x86_64. If it matters I'll try to reproduce this
> > > error on a non tainted kernel.
> > 
> > No need to reproduce on a non-tainted Kernel.  This is a known issue
> > with patches merged into the v4l-dvb tree several weeks ago but it seems
> > to not have made it into 2.6.25 :(
> > 
> >  http://linuxtv.org/hg/v4l-dvb/rev/06eb92ed0b18
> >  http://linuxtv.org/hg/v4l-dvb/rev/c50180f4ddfc
> > 
> > I can rebase the patches for 2.6.25 but they are too big to go into the
> > stable 2.6.25 tree...
> > 
> > Thanks for the report,
> > 
> > 	Brandon
> > 
> 
> hmm, because of that 100 lines only rule including offsets?
> 
> The current v4l-dvb on 2.6.24 has 233 modules.
> 
> It is usual that changes, if needed, are going over lots of them.
> 
> How far one can come with _such_ rules, given that one single line
> changed counts up to seven with the offsets?
> 
> How can one even comment on that brain damage?
> 

There is no "100 line rule" for -stable patches, if that is what you were
referring to.

Please just send the patches to stable@kernel.org, along with a full
description of why they are needed in 2.6.25.x.  If those fine folk see a
problem with merging the patches then they will explain that problem and
discussion will ensue.  It will not involve the term "100 line rule"!