From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 5A02A6B0003 for ; Sat, 3 Nov 2018 14:32:13 -0400 (EDT) Received: by mail-pl1-f199.google.com with SMTP id bb3-v6so5147412plb.20 for ; Sat, 03 Nov 2018 11:32:13 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id f5-v6sor36608042pgs.87.2018.11.03.11.32.11 for (Google Transport Security); Sat, 03 Nov 2018 11:32:11 -0700 (PDT) Date: Sat, 3 Nov 2018 11:32:08 -0700 From: Joel Fernandes Subject: Re: [PATCH -next 0/3] Add support for fast mremap Message-ID: <20181103183208.GA56850@google.com> References: <20181103040041.7085-1-joelaf@google.com> <6886607.O3ZT5bM3Cy@blindfold> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Anton Ivanov Cc: Richard Weinberger , linux-kernel@vger.kernel.org, kernel-team@android.com, akpm@linux-foundation.org, Andrey Ryabinin , Andy Lutomirski , Borislav Petkov , Catalin Marinas , Chris Zankel , dancol@google.com, Dave Hansen , "David S. Miller" , elfring@users.sourceforge.net, Fenghua Yu , Geert Uytterhoeven , Guan Xuetao , Helge Deller , hughd@google.com, Ingo Molnar , "James E.J. Bottomley" , Jeff Dike , Jonas Bonn , Julia Lawall , kasan-dev@googlegroups.com, kirill@shutemov.name, kvmarm@lists.cs.columbia.edu, Ley Foon Tan , linux-alpha@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vge.kvack.org, r.kernel.org@lithops.sigma-star.at, linux-m68k@lists.linux-m68k.org, linux-mips@linux-mips.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, lokeshgidra@google.com, Max Filippov , Michal Hocko , minchan@kernel.org, nios2-dev@lists.rocketboards.org, pantin@google.com, Peter Zijlstra , Rich Felker , Sam Creasey , sparclinux@vger.kernel.org, Stafford Horne , Stefan Kristiansson , Thomas Gleixner , Tony Luck , Will Deacon , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Yoshinori Sato On Sat, Nov 03, 2018 at 09:24:05AM +0000, Anton Ivanov wrote: > On 03/11/2018 09:15, Richard Weinberger wrote: > > Joel, > > > > Am Samstag, 3. November 2018, 05:00:38 CET schrieb Joel Fernandes: > > > Hi, > > > Here is the latest "fast mremap" series. This just a repost with Kirill's > > > Acked-bys added. I would like this to be considered for linux -next. I also > > > dropped the CONFIG enablement patch for arm64 since I am yet to test it with > > > the new TLB flushing code that is in very recent kernel releases. (None of my > > > arm64 devices run mainline right now.) so I will post the arm64 enablement once > > > I get to that. The performance numbers in the series are for x86. > > > > > > List of patches in series: > > > > > > (1) mm: select HAVE_MOVE_PMD in x86 for faster mremap > > > > > > (2) mm: speed up mremap by 20x on large regions (v4) > > > v1->v2: Added support for per-arch enablement (Kirill Shutemov) > > > v2->v3: Updated commit message to state the optimization may also > > > run for non-thp type of systems (Daniel Col). > > > v3->v4: Remove useless pmd_lock check (Kirill Shutemov) > > > Rebased ontop of Linus's master, updated perf results based > > > on x86 testing. Added Kirill's Acks. > > > > > > (3) mm: treewide: remove unused address argument from pte_alloc functions (v2) > > > v1->v2: fix arch/um/ prototype which was missed in v1 (Anton Ivanov) > > > update changelog with manual fixups for m68k and microblaze. > > > > > > not included - (4) mm: select HAVE_MOVE_PMD in arm64 for faster mremap > > > This patch is dropped since last posting pending further performance > > > testing on arm64 with new TLB gather updates. See notes in patch > > > titled "mm: speed up mremap by 500x on large regions" for more > > > details. > > > > > This breaks UML build: > > CC mm/mremap.o > > mm/mremap.c: In function a??move_normal_pmda??: > > mm/mremap.c:229:2: error: implicit declaration of function a??set_pmd_ata??; did you mean a??set_pte_ata??? [-Werror=implicit-function-declaration] > > set_pmd_at(mm, new_addr, new_pmd, pmd); > > ^~~~~~~~~~ > > set_pte_at > > CC crypto/rng.o > > CC fs/direct-io.o > > cc1: some warnings being treated as errors > > > > To test yourself, just run on a x86 box: > > $ make defconfig ARCH=um > > $ make linux ARCH=um > > > > Thanks, > > //richard > > > > > > > > UM somehow managed to miss one of the 3-level functions, I sent a patch at > some point to add to the mmremap series, but it looks like it did not get > included in the final version. > > You need these two incremental on top of Joel's patch. Richard - feel free > to relocate the actual implementation of the set_pgd_at elsewhere - I put it > at the end of tlb.c > > diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h > index 7485398d0737..1692da55e63a 100644 > --- a/arch/um/include/asm/pgtable.h > +++ b/arch/um/include/asm/pgtable.h > @@ -359,4 +359,7 @@ do {A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A \ > A A A A A A A __flush_tlb_one((vaddr));A A A A A A A A A A A A A A \ > A } while (0) > > +extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, > +A A A A A A A A A A A A A A pmd_t *pmdp, pmd_t pmd); > + > A #endif > diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c > index 763d35bdda01..d17b74184ba0 100644 > --- a/arch/um/kernel/tlb.c > +++ b/arch/um/kernel/tlb.c > @@ -647,3 +647,9 @@ void force_flush_all(void) > A A A A A A A A A A A A A A A vma = vma->vm_next; > A A A A A A A } > A } > +void set_pmd_at(struct mm_struct *mm, unsigned long addr, > +A A A A A A A A A A A A A A pmd_t *pmdp, pmd_t pmd) > +{ > +A A A A A A *pmdp = pmd; > +} > + > Looks like more architectures don't define set_pmd_at. I am thinking the easiest way forward is to just do the following, instead of defining set_pmd_at for every architecture that doesn't care about it. Thoughts? diff --git a/mm/mremap.c b/mm/mremap.c index 7cf6b0943090..31ad64dcdae6 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -281,7 +281,8 @@ unsigned long move_page_tables(struct vm_area_struct *vma, split_huge_pmd(vma, old_pmd, old_addr); if (pmd_trans_unstable(old_pmd)) continue; - } else if (extent == PMD_SIZE && IS_ENABLED(CONFIG_HAVE_MOVE_PMD)) { + } else if (extent == PMD_SIZE) { +#ifdef CONFIG_HAVE_MOVE_PMD /* * If the extent is PMD-sized, try to speed the move by * moving at the PMD level if possible. @@ -296,6 +297,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma, drop_rmap_locks(vma); if (moved) continue; +#endif } if (pte_alloc(new_vma->vm_mm, new_pmd))