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* linux-2.5.40 64GB highmem BUG()
@ 2002-10-07 13:27 Adam J. Richter
  2002-10-08  0:48 ` Thomas Molina
  2002-12-19 23:36 ` William Lee Irwin III
  0 siblings, 2 replies; 6+ messages in thread
From: Adam J. Richter @ 2002-10-07 13:27 UTC (permalink / raw)
  To: linux-kernel

	Although 2.5.40 has been out for a while, I think I ought
to post this bug as I haven't seen any other mention of it.

	When I boot an 2.5.40 x86 kernel built with CONFIG_HIGHMEM64G,
and with a 920kB initial ramdisk (2.2MB uncompressed), I get a kernel
BUG() at highmem.c line 480, preceded by a message saying "scheduling
with KM_TYPE 15 held!"  The machine on which I experienced this
problem has 1.25GB of RAM.  The problem occurs with and without
CONFIG_PREEMPT.  All kernels that tried were SMP kernels running on a
uniprocessor.

	The problem does not occur if I build 2.5.40 with
CONFIG_HIGHMEM4G or CONFIG_NOHIGMEM.  So, it's probably not causing
problems for many people, but I thought I should report it anyhow.

Adam J. Richter     __     ______________   575 Oroville Road
adam@yggdrasil.com     \ /                  Milpitas, California 95035
+1 408 309-6081         | g g d r a s i l   United States of America
                         "Free Software For The Rest Of Us."

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: linux-2.5.40 64GB highmem BUG()
@ 2002-10-08  1:12 Adam J. Richter
  0 siblings, 0 replies; 6+ messages in thread
From: Adam J. Richter @ 2002-10-08  1:12 UTC (permalink / raw)
  To: tmolina; +Cc: linux-kernel

On 2002-10-08 0:48:32, Thomas Molina wrote:
>On Mon, 7 Oct 2002, Adam J. Richter wrote:
>
>>       Although 2.5.40 has been out for a while, I think I ought
>> to post this bug as I haven't seen any other mention of it.
>> 
>>       When I boot an 2.5.40 x86 kernel built with CONFIG_HIGHMEM64G,
>> and with a 920kB initial ramdisk (2.2MB uncompressed), I get a kernel
>> BUG() at highmem.c line 480, preceded by a message saying "scheduling
>> with KM_TYPE 15 held!"  The machine on which I experienced this
>> problem has 1.25GB of RAM.  The problem occurs with and without
>> CONFIG_PREEMPT.  All kernels that tried were SMP kernels running on a
>> uniprocessor.
>> 
>>       The problem does not occur if I build 2.5.40 with
>> CONFIG_HIGHMEM4G or CONFIG_NOHIGMEM.  So, it's probably not causing
>> problems for many people, but I thought I should report it anyhow.
>
>Does the accompanying trace output say BUG(), or is there a might_sleep() 
>in the trace output?  In other words, is it a scheduling while holding a 
>lock kind of thing?

	It is the BUG() statement in check_highmem_ptes in mm/highmem.c:

#if CONFIG_DEBUG_HIGHMEM
void check_highmem_ptes(void)
{
        int idx, type;

        preempt_disable();
        for (type = 0; type < KM_TYPE_NR; type++) {
                idx = type + KM_TYPE_NR*smp_processor_id();
                if (!pte_none(*(kmap_pte-idx))) {
                        printk("scheduling with KM_TYPE %d held!\n", type);
                        BUG();
                }
        }
        preempt_enable();
}
#endif

	I'm updating to 2.5.41 and will post a trace if the problem
still occurs.

Adam J. Richter     __     ______________   575 Oroville Road
adam@yggdrasil.com     \ /                  Milpitas, California 95035
+1 408 309-6081         | g g d r a s i l   United States of America
                         "Free Software For The Rest Of Us."

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: linux-2.5.40 64GB highmem BUG()
@ 2002-12-21  9:43 Adam J. Richter
  2002-12-21  9:48 ` William Lee Irwin III
  0 siblings, 1 reply; 6+ messages in thread
From: Adam J. Richter @ 2002-12-21  9:43 UTC (permalink / raw)
  To: wli; +Cc: linux-kernel

>> 	Although 2.5.40 has been out for a while, I think I ought
>> to post this bug as I haven't seen any other mention of it.
>> 	When I boot an 2.5.40 x86 kernel built with CONFIG_HIGHMEM64G,
>> and with a 920kB initial ramdisk (2.2MB uncompressed), I get a kernel
>> BUG() at highmem.c line 480, preceded by a message saying "scheduling
>> with KM_TYPE 15 held!"  The machine on which I experienced this
>> problem has 1.25GB of RAM.  The problem occurs with and without
>> CONFIG_PREEMPT.  All kernels that tried were SMP kernels running on a
>> uniprocessor.

>This is not reproducible here with 2.5.52-mm2. Is the initrd required
>to trigger this?

	Yes, the initrd seems to be required.  It happens when
the initrd attempts to mount /proc (it runs a shell script that
starts by setting PATH, mounting /dev, and mounting /proc).

	I've verified that under 2.5.52 the problem occurs with
CONFIG_HIGHME64G and not with CONFIG_HIGHMEM4G.  Actually, now the
problem is a BUG() at slab.c:1451, which is also memory corruption,
and I suspect just an evolution of the same problem from 2.5.40.

	Anyhow, in case it helps you, I've put the vmlinux and initrd
that produce this problem in
ftp://ftp.yggdrasil.com/private/adam/for-wli/.  Note that the ramdisk
has kernel modules that don't match the kernel but that's not the
issue, as I configured that kernel to have a different version name.

       Thanks for your attention to this problem.

Adam J. Richter     __     ______________   575 Oroville Road
adam@yggdrasil.com     \ /                  Milpitas, California 95035
+1 408 309-6081         | g g d r a s i l   United States of America
                         "Free Software For The Rest Of Us."

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2002-12-21  9:41 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2002-10-07 13:27 linux-2.5.40 64GB highmem BUG() Adam J. Richter
2002-10-08  0:48 ` Thomas Molina
2002-12-19 23:36 ` William Lee Irwin III
2002-10-08  1:12 Adam J. Richter
2002-12-21  9:43 Adam J. Richter
2002-12-21  9:48 ` William Lee Irwin III

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