On Tue, Sep 23, 2014 at 12:29:27PM +0400, Vladimir Davydov wrote: > On Mon, Sep 22, 2014 at 10:52:50PM -0700, Greg Thelen wrote: > > In this condition, if res usage is at limit then there's no point in > > swapping because memsw.usage is already maximal. Prior to this patch > > I think the kernel did the right thing, but not afterwards. > > > > Before this patch: > > if res.usage == res.limit, try_charge() indirectly calls > > try_to_free_mem_cgroup_pages(noswap=true) > > But this is wrong. If we fail to charge res, we should try to do swap > out along with page cache reclaim. Swap out won't affect memsw.usage, > but will diminish res.usage so that the allocation may succeed. Oops, I missed your point, sorry. If we hit the res.limit and memsw.limit=res.limit, we automatically hit memsw.limit too, so there's no point swapping out. Thanks, Vladimir -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>