From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bharata B Rao Subject: Re: [PATCH 2/2] mm: remove extra ZONE_DEVICE struct page refcount Date: Tue, 29 Sep 2020 08:29:41 +0530 Message-ID: <20200929025941.GA257792@in.ibm.com> References: <20200925204442.31348-1-rcampbell@nvidia.com> <20200925204442.31348-3-rcampbell@nvidia.com> Reply-To: bharata-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20200925204442.31348-3-rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: Ralph Campbell Cc: Yang Shi , Zi Yan , nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Alistair Popple , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-ppc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Paul Mackerras , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Matthew Wilcox , Jason Gunthorpe , Dan Williams , Andrew Morton , Ira Weiny , Christoph Hellwig , "Kirill A . Shutemov" , Ben Skeggs List-Id: nouveau.vger.kernel.org On Fri, Sep 25, 2020 at 01:44:42PM -0700, Ralph Campbell wrote: > ZONE_DEVICE struct pages have an extra reference count that complicates the > code for put_page() and several places in the kernel that need to check the > reference count to see that a page is not being used (gup, compaction, > migration, etc.). Clean up the code so the reference count doesn't need to > be treated specially for ZONE_DEVICE. > > Signed-off-by: Ralph Campbell > --- > arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +- > drivers/gpu/drm/nouveau/nouveau_dmem.c | 2 +- > include/linux/dax.h | 2 +- > include/linux/memremap.h | 7 ++- > include/linux/mm.h | 44 -------------- > lib/test_hmm.c | 2 +- > mm/gup.c | 44 -------------- > mm/internal.h | 8 +++ > mm/memremap.c | 82 ++++++-------------------- > mm/migrate.c | 5 -- > mm/page_alloc.c | 3 + > mm/swap.c | 46 +++------------ > 12 files changed, 44 insertions(+), 203 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c > index 7705d5557239..e6ec98325fab 100644 > --- a/arch/powerpc/kvm/book3s_hv_uvmem.c > +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c > @@ -711,7 +711,7 @@ static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm) > > dpage = pfn_to_page(uvmem_pfn); > dpage->zone_device_data = pvt; > - get_page(dpage); > + init_page_count(dpage); The powerpc change looks good. Passes a quick sanity test of booting/rebooting a secure guest on Power. Tested-by: Bharata B Rao Regards, Bharata.