Le 27/11/2018 à 10:58, Alexandre Belloni a écrit :
> Hello Richard,
>
> On 27/11/2018 10:51:13+0100, richard.genoud@xxxxxxxxx wrote:
>> Hi all,
>>
>> I reproduced the memory leak on my board (at91sam9g35-cm) with a 4.20-rc3.
>>
>> It triggered an OOM after a couple of hours running a code like this:
>> #include <sys/types.h>
>> #include <sys/stat.h>
>> #include <fcntl.h>
>> #include <unistd.h>
>>
>>
>> int main(int argc, char **argv)
>> {
>> int fd;
>> do {
>> fd = open("/dev/ttyS1", O_RDONLY);
>> close(fd);
>> } while (true);
>> return 0;
>> }
>>
>> As Mario pointed out, this only happens when atmel,use-dma-{r,t}x are
>> used in the device-tree.
>>
>> Adding:
>> CONFIG_DEBUG_SLAB=y
>> CONFIG_DEBUG_SLAB_LEAK=y
>> Doesn't show anything suspect in /proc/slab_allocators
>>
>> From what I found until now, it's something done in :
>> dma_request_slave_channel();
>> that leaks kmalloc-32
>> Mabe I missed something, but it seems that everything DMA related is
>> deallocated in atmel_release_{tx,rx}_dma().
>>
>> Is this ringing a bell ?
>>
>
> Yes, this is known issue and it has yet to be worked on.
>
After a talk on freenode, Alex found the problem.
A patch is on its way.
Thanks !
