On Fri 2015-11-27 19:49:48, kbuild test robot wrote:
> Hi Petr,
>
> [auto build test WARNING on powerpc/next]
> [also build test WARNING on v4.4-rc2 next-20151127]
> [cannot apply to tip/x86/core]
>
> url:
> https://github.com/0day-ci/linux/commits/Petr-Mladek/Clea
Testing has shown that the backtrace sometimes does not fit
into the 4kB temporary buffer that is used in NMI context.
The warnings are gone when I double the temporary buffer size.
Note that this problem existed even in the x86-specific
implementation that was added by the commit a9edc8809328
("
We could not resize the temporary buffer in NMI context. Let's warn
if a message is lost.
This is rather theoretical. printk() should not be used in NMI.
The only sensible use is when we want to print backtrace from all
CPUs. The current buffer should be enough for this purpose.
Signed-off-by: Pe
Oops messages are important for debugging. We should try hard to get
them directly into the ring buffer and print them to the console
even in NMI context. This is problematic because the needed locks
might already be taken.
What we can do, though, is to zap all printk locks. We already do this
whe
NMIs could happen at any time. This patch makes sure that the safe
printk() in NMI will schedule IRQ work only when the related
structs are initialized.
All pending messages are flushed when the IRQ work is being
initialized.
Signed-off-by: Petr Mladek
---
kernel/printk/nmi.c | 13 -
printk() takes some locks and could not be used a safe way in NMI
context.
The chance of a deadlock is real especially when printing
stacks from all CPUs. This particular problem has been addressed
on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack
trace on all CPUs").
This pat
This patch set generalizes the already existing solution for
printing NMI messages. The main idea comes from Peter Zijlstra.
This second version has only few changes in compare with v1, see
below. Peter Zijlstra suggested to improve also handling of
the serial console. I looked into tit and it see
On Thursday 26 November 2015 13:39:09 Thomas Huth wrote:
> On 26/11/15 13:09, Michael Ellerman wrote:
> > On Thu, 2015-11-26 at 11:47 +0100, Thomas Huth wrote:
> >
> >> On 26/11/15 01:59, Rashmica Gupta wrote:
> >
> >>> All users of QPACE have upgraded to QPACE2 so remove the Cell QPACE code.
> >
Hi Peter,
On Fri, Nov 27, 2015 at 2:09 PM, Petr Mladek wrote:
> printk() takes some locks and could not be used a safe way in NMI
> context.
>
> The chance of a deadlock is real especially when printing
> stacks from all CPUs. This particular problem has been addressed
> on x86 by the commit a9ed
https://github.com/0day-ci/linux
Petr-Mladek/Cleaning-printk-stuff-in-NMI-context/20151127-191620
bafdcb831ce105cb7ff2b9e11acfcf3764da11b9 printk/nmi: Increase the size of the
temporary buffer
include/asm-generic/percpu.h:111:2: error: implicit declaration of function
'preempt_di
Hi Petr,
[auto build test ERROR on: powerpc/next]
[also build test ERROR on: v4.4-rc2 next-20151127]
[cannot apply to: tip/x86/core]
url:
https://github.com/0day-ci/linux/commits/Petr-Mladek/Cleaning-printk-stuff-in-NMI-context/20151127-191620
base: https://git.kernel.org/pub/scm/linux
"Aneesh Kumar K.V" writes:
> "Aneesh Kumar K.V" writes:
>
>> Now that we don't track 4k subpage information we can use 2K PTE
>> fragments.
>>
>> Signed-off-by: Aneesh Kumar K.V
>> ---
>> arch/powerpc/include/asm/book3s/64/hash-64k.h | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(
Hi Petr,
[auto build test WARNING on powerpc/next]
[also build test WARNING on v4.4-rc2 next-20151127]
[cannot apply to tip/x86/core]
url:
https://github.com/0day-ci/linux/commits/Petr-Mladek/Cleaning-printk-stuff-in-NMI-context/20151127-191620
base: https://git.kernel.org/pub/scm/linux
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