From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 04/15] arm64: switch to generic version of pte allocation Date: Fri, 3 May 2019 11:05:09 +0100 Message-ID: <20190503100508.GB47811@lakrids.cambridge.arm.com> References: <1556810922-20248-1-git-send-email-rppt@linux.ibm.com> <1556810922-20248-5-git-send-email-rppt@linux.ibm.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <1556810922-20248-5-git-send-email-rppt@linux.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mike Rapoport Cc: Michal Hocko , Catalin Marinas , Palmer Dabbelt , linux-mips@vger.kernel.org, Guo Ren , linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, Helge Deller , x86@kernel.org, Russell King , Matthew Wilcox , Geert Uytterhoeven , Matt Turner , Sam Creasey , Arnd Bergmann , linux-um@lists.infradead.org, Richard Weinberger , linux-m68k@lists.linux-m68k.org, Greentime Hu , nios2-dev@lists.rocketboards.org, Guan Xuetao , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Kuo , Paul Burton Hi, On Thu, May 02, 2019 at 06:28:31PM +0300, Mike Rapoport wrote: > The PTE allocations in arm64 are identical to the generic ones modulo the > GFP flags. > > Using the generic pte_alloc_one() functions ensures that the user page > tables are allocated with __GFP_ACCOUNT set. > > The arm64 definition of PGALLOC_GFP is removed and replaced with > GFP_PGTABLE_USER for p[gum]d_alloc_one() and for KVM memory cache. > > The mappings created with create_pgd_mapping() are now using > GFP_PGTABLE_KERNEL. > > The conversion to the generic version of pte_free_kernel() removes the NULL > check for pte. > > The pte_free() version on arm64 is identical to the generic one and > can be simply dropped. > > Signed-off-by: Mike Rapoport > --- > arch/arm64/include/asm/pgalloc.h | 43 ++++------------------------------------ > arch/arm64/mm/mmu.c | 2 +- > arch/arm64/mm/pgd.c | 4 ++-- > virt/kvm/arm/mmu.c | 2 +- > 4 files changed, 8 insertions(+), 43 deletions(-) [...] > diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c > index 289f911..2ef1a53 100644 > --- a/arch/arm64/mm/pgd.c > +++ b/arch/arm64/mm/pgd.c > @@ -31,9 +31,9 @@ static struct kmem_cache *pgd_cache __ro_after_init; > pgd_t *pgd_alloc(struct mm_struct *mm) > { > if (PGD_SIZE == PAGE_SIZE) > - return (pgd_t *)__get_free_page(PGALLOC_GFP); > + return (pgd_t *)__get_free_page(GFP_PGTABLE_USER); > else > - return kmem_cache_alloc(pgd_cache, PGALLOC_GFP); > + return kmem_cache_alloc(pgd_cache, GFP_PGTABLE_USER); > } In efi_virtmap_init() we use pgd_alloc() to allocate a pgd for EFI runtime services, which we map with a special kernel page table. I'm not sure if accounting that is problematic, as it's allocated in a kernel thread off the back of an early_initcall. Just to check, Is that sound, or do we need a pgd_alloc_kernel()? Thanks, Mark.