Linux Virtualization - Aug 2018 - [PATCH v3 2/2] virtio_balloon: replace oom notifier with shrinker

On 2018/08/03 17:32, Wei Wang wrote:
> +static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
> +{
> +	vb->shrinker.scan_objects = virtio_balloon_shrinker_scan;
> +	vb->shrinker.count_objects = virtio_balloon_shrinker_count;
> +	vb->shrinker.batch = 0;
> +	vb->shrinker.seeks = DEFAULT_SEEKS;
Why flags field is not set? If vb is allocated by kmalloc(GFP_KERNEL)
and is nowhere zero-cleared, KASAN would complain it.
> +
> +	return register_shrinker(&vb->shrinker);
> +}

On 08/03/2018 08:11 PM, Tetsuo Handa wrote:
> On 2018/08/03 17:32, Wei Wang wrote:
>> +static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
>> +{
>> +	vb->shrinker.scan_objects = virtio_balloon_shrinker_scan;
>> +	vb->shrinker.count_objects = virtio_balloon_shrinker_count;
>> +	vb->shrinker.batch = 0;
>> +	vb->shrinker.seeks = DEFAULT_SEEKS;
> Why flags field is not set? If vb is allocated by kmalloc(GFP_KERNEL)
> and is nowhere zero-cleared, KASAN would complain it.
Could you point where in the code that would complain it?
I only see two shrinker flags (NUMA_AWARE and MEMCG_AWARE), and they 
seem not related to that.


Best,
Wei

On 2018/08/06 18:56, Wei Wang wrote:
> On 08/03/2018 08:11 PM, Tetsuo Handa wrote:
>> On 2018/08/03 17:32, Wei Wang wrote:
>>> +static int virtio_balloon_register_shrinker(struct virtio_balloon
*vb)
>>> +{
>>> +??? vb->shrinker.scan_objects = virtio_balloon_shrinker_scan;
>>> +??? vb->shrinker.count_objects = virtio_balloon_shrinker_count;
>>> +??? vb->shrinker.batch = 0;
>>> +??? vb->shrinker.seeks = DEFAULT_SEEKS;
>> Why flags field is not set? If vb is allocated by kmalloc(GFP_KERNEL)
>> and is nowhere zero-cleared, KASAN would complain it.
> 
> Could you point where in the code that would complain it?
> I only see two shrinker flags (NUMA_AWARE and MEMCG_AWARE), and they seem
not related to that.
Where is vb->shrinker.flags initialized?