On Tue, Jan 15, 2019 at 06:40:36PM +0100, Michal Hocko wrote:
On Tue 15-01-19 16:51:31, Greg KH wrote:
On Tue, Jan 15, 2019 at 04:34:44PM +0100, Michal Hocko wrote:
I do not see a straightforward backport of this patch without pulling more changes in. Do we have anybody to actually hit the issue on those older kernels? While the issue is possible in principle I do not remember anybody complaining.
If no one is complaining, that's fine, you just got this message because you put this in the commit:
Fixes: c3b94f44fcb0 ("memcg: further prevent OOM with too many dirty pages")
Which means any kernel newer than 4.2 (and some older stable releases) has the issue that this patch is trying to fix. If it doesn't need to be backported that far, wonderful!
After a second thought, we are not really affected all the way down to c3b94f44fcb0. We do account page tables to memcgs only since 3e79ec7ddc33 ("arch: x86: charge page tables to kmemcg") 4.8+. Without that there is no realy memcg reclaim and thus not wait_on_page_writeback.
So my Fixes is a bit misleading. Sorry about that.
Not a problem, thanks for looking into it. As you say 4.8+, this didn't apply to 4.9 either, so do I need to look into doing a manual backport there?
thanks,
greg k-h