Re: Commit 597ce1723 (MIPS: Support for 64-bit FP with O32 binaries) causing qemu hang with mips64 kernels

[Guenter Roeck <linux@roeck-us.net>]

On 02/07/2014 07:57 PM, Huacai Chen wrote:
> Hi,
>
> Maybe you can try this:
> http://patchwork.linux-mips.org/patch/6506/
> http://patchwork.linux-mips.org/patch/6507/
>
With those two patches applied the problem is gone.

Thanks a lot!

Guenter

> On Sat, Feb 8, 2014 at 11:39 AM, Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> Hi all,
>>
>> in 3.14-rc1, my mips64 qemu test fails. The image boots and then hangs.
>> Bisect points to commit 597ce1723 (MIPS: Support for 64-bit FP with O32
>> binaries).
>> Reverting this commit fixes the problem. Disabling MIPS_O32_FP64_SUPPORT
>> in my test image does _not_ solve the problem. The qemu version does not
>> seem
>> to make a difference; I tested with qemu 1.6.0 and 1.7.0.
>>
>> Console log output is available in
>> http://server.roeck-us.net:8010/builders/qemu-mips64-master/builds/34/steps/buildcommand/logs/stdio
>>
>> When the problem is seen, the emulation hangs as can be seen in the log,
>> and the qemu process consumes 100% CPU until it is killed.
>>
>> qemu command line is
>>
>> qemu-system-mips64 -kernel vmlinux -M malta -hda
>> core-image-minimal-qemumips64.ext3 \
>> -vga cirrus -usb -usbdevice wacom-tablet -no-reboot -m 128 --append
>> "root=/dev/hda \
>> rw mem=128M console=ttyS0 console=tty" -nographic
>>
>> The same configuration works fine with earlier kernels. I'll be happy to
>> provide
>> the detailed configuration as well as the root file system for testing if
>> needed.
>>
>> Obviously I have no idea if this is a problem with the patch or with qemu.
>> If there is anything I can do to help tracking down the problem further,
>> please let me know.
>>
>> Thanks,
>> Guenter
>>
>
>