Re: mm: mkfs.ext4 invoked oom-killer on i386 - pagecache_get_page

[Chris Down]

Yafang Shao writes:
> Look at this patch[1] carefully you will find that it introduces the
> same issue that I tried to fix in another patch [2]. Even more sad is
> these two patches are in the same patchset. Although this issue isn't
> related with the issue found by Naresh, we have to ask ourselves why
> we always make the same mistake ?
> One possible answer is that we always forget the lifecyle of
> memory.emin before we read it. memory.emin doesn't have the same
> lifecycle with the memcg, while it really has the same lifecyle with
> the reclaimer. IOW, once a reclaimer begins the protetion value should
> be set to 0, and after we traversal the memcg tree we calculate a
> protection value for this reclaimer, finnaly it disapears after the
> reclaimer stops. That is why I highly suggest to add an new protection
> member in scan_control before.

I agree with you that the e{min,low} lifecycle is confusing for everyone -- the 
only thing I've not seen confirmation of is any confirmed correlation with the 
i386 oom killer issue. If you've validated that, I'd like to see the data :-)