lkml.org 
[lkml]   [2011]   [Jul]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [GIT PULL v2] sched: Make sleep inside atomic detection work on !PREEMPT
On Fri, Jul 01, 2011 at 02:36:29PM +0200, Ingo Molnar wrote:
>
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
>
> > On Fri, Jun 10, 2011 at 03:30:18PM +0200, Frederic Weisbecker wrote:
> > > Ingo,
> > >
> > > Please pull the sched/core branch that can be found at:
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing.git
> > > sched/core
> >
> > Hi Ingo,
> >
> > I have added Randy's ack on the last patch. To get it, please pull the v2 in
> > the following branch:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing.git
> > sched/core-v2
> >
> > There are no other changes.
>
> Hm, this triggers such warnings now:
>
> Detected 2010.217 MHz processor.
> Marking TSC unstable due to TSCs unsynchronized
> Calibrating delay loop (skipped), value calculated using timer frequency.. 4022.95 BogoMIPS (lpj=6700723)
> pid_max: default: 4096 minimum: 301
> BUG: scheduling while atomic: swapper/0/0x10000002
> no locks held by swapper/0.
> Pid: 0, comm: swapper Not tainted 3.0.0-rc5-tip-01401-ga7adf5f-dirty #141020
> Call Trace:
> [<ffffffff81ddb3b0>] __schedule_bug+0x60/0x65
> [<ffffffff81dee803>] schedule+0x953/0x980
> [<ffffffff81571e30>] ? serial8250_console_putchar+0x30/0x40
> [<ffffffff81df177b>] ? _raw_spin_unlock+0x2b/0x50
> [<ffffffff8107882a>] __cond_resched+0x2a/0x40
> [<ffffffff81dee8e2>] _cond_resched+0x32/0x40
> [<ffffffff81110ba8>] __alloc_pages_nodemask+0x1b8/0x880
> [<ffffffff81df23ce>] ? common_interrupt+0xe/0x13
> [<ffffffff81080649>] ? vprintk+0x359/0x530
> [<ffffffff8113b4e7>] slob_new_pages+0x17/0x80
> [<ffffffff8113bd13>] __kmalloc_node+0xa3/0x270
> [<ffffffff81ddb6d5>] ? printk+0x41/0x43
> [<ffffffff82738420>] pidmap_init+0x80/0xbf
> [<ffffffff8272aa54>] start_kernel+0x28b/0x300
> [<ffffffff8272a2ee>] x86_64_start_reservations+0xfe/0x102
> [<ffffffff8272a3e2>] x86_64_start_kernel+0xf0/0xf7
> Security Framework initialized
> AppArmor: AppArmor initialized
> Mount-cache hash table entries: 256
> Initializing cgroup subsys cpuacct
>
> Not sure we want to warn about schedule during early init, or can it
> cause problems and should thus be fixed? I bet there's more such
> instances.

I believe this is harmless because no other other tasks than init are queued at that
time. But I don't know, may be calling schedule() involves some things that
are not ready yet at that time.

Either we add a system_state check in schedule_debug() or we fix the callers
to not call schedule when system_state shows we are booting..


\
 
 \ /
  Last update: 2011-07-01 14:59    [W:0.074 / U:6.904 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site