On 08/10/20 09:53, yulei.kernel@xxxxxxxxx wrote: > From: Yulei Zhang <yuleixzhang@xxxxxxxxxxx> > > x86 pat uses 'struct page' by only checking if it's system ram, > however it is not true if dmem is used, let's teach pat to > recognize this case if it is ram but it is !pfn_valid() > > We always use WB for dmem and any attempt to change this > behavior will be rejected and WARN_ON is triggered > > Signed-off-by: Xiao Guangrong <gloryxiao@xxxxxxxxxxx> > Signed-off-by: Yulei Zhang <yuleixzhang@xxxxxxxxxxx> Hooks like these will make it very hard to merge this series. I like the idea of struct page-backed memory, but this is a lot of code and I wonder if it's worth adding all these complications. One can already use mem= to remove the "struct page" cost for most of the host memory, and manage the allocation of the remaining memory in userspace with /dev/mem. What is the advantage of doing this in the kernel? Paolo
