From patchwork Wed Oct 14 00:53:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kalesh Singh X-Patchwork-Id: 11837093 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4F4F014B5 for ; Wed, 14 Oct 2020 09:19:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 253E220878 for ; Wed, 14 Oct 2020 09:19:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="G3gn7F39" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730424AbgJNJTy (ORCPT ); Wed, 14 Oct 2020 05:19:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730448AbgJNJTk (ORCPT ); Wed, 14 Oct 2020 05:19:40 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DFACC0251B6 for ; Tue, 13 Oct 2020 17:54:14 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id ec4so1077656qvb.21 for ; Tue, 13 Oct 2020 17:54:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:cc; bh=TvfbBMDu2+s5YUKb/QcLi0FhzELrCQpbsXkcpSpM+Nk=; b=G3gn7F39iSNCnEd7q8+PVe/kEIgBPlqHPHHGmF2OPFgrjxC5QoofX4MDKRT2oC2O9r hV6n/EbqK4wdl8qi76HX5kMbwSIvdJepo6MbII62VZq0Uy9vM7eSpi7J/fSzRBT/x9VJ JmtkqQIxbilR0WKfR9oQqXFr+CHI0qaZQjOkejT7V7SEYKvDoY1wJYkfB/RI+1G+l9wa 4F+5fRoIJwXTMOXh4Al28eIZc71nv6AtVZ00GVY1xil+lb0YwwPFO+2RInHsXiVBfhWx 25Jblpp8+HkwMPVx/nTi2L97HVLH2HmXAPfuxhlAVRLFAVdeUvqn9aN9v2fAuYxiIA5i 9iKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:cc; bh=TvfbBMDu2+s5YUKb/QcLi0FhzELrCQpbsXkcpSpM+Nk=; b=BrSkiMKajsQmpa9WdokXKq/FI+s6Aea09CU7YxpU7gcaaiEAIojeiFgwwW1kZj7lfI VAqzsXYAj6eDmms+EFWz1xSY7nB2T9NArle2s2BtqL7i6uWWtYud2IeEbJgP8aus53f+ k2Oyp5WYfLqc0W6JBoFbzEqaryElxDmAm/sRArOU98pfqH2ra86K/AYnOb9LB4nEqsdc Fi0ES6qbK+dZjJNxXlMC9v+2hPd4tAZlH2Xqy4FDTkjh/tc6d2V47ufvVbCaOUqNMdxZ QSvXl3I7TjYZ18E6NySGKauSVQCbx64PE5vWs3Kde/1ITsJjiWO0LnqkdcvyqFzmS7HS nxaQ== X-Gm-Message-State: AOAM531pboeX8YyggL2avv0CRpHxvgh6zMLrw9hzGYoAyUG6TXnT0+Xo jvxXfEq/jxaFhH9VuiO3N+E5PS5A9k7qZLYzyQ== X-Google-Smtp-Source: ABdhPJw3tFbAz+wnBZvW4VQhuqFS/HjgU1bMTVbFcRuRjcOeKAwU0JK4uA8tv1QRCL/TMwPmerYSJ8B0YbB0LRqP4g== Sender: "kaleshsingh via sendgmr" X-Received: from kaleshsingh.c.googlers.com ([fda3:e722:ac3:10:14:4d90:c0a8:2145]) (user=kaleshsingh job=sendgmr) by 2002:ad4:46a8:: with SMTP id br8mr2664505qvb.24.1602636853194; Tue, 13 Oct 2020 17:54:13 -0700 (PDT) Date: Wed, 14 Oct 2020 00:53:07 +0000 In-Reply-To: <20201014005320.2233162-1-kaleshsingh@google.com> Message-Id: <20201014005320.2233162-3-kaleshsingh@google.com> Mime-Version: 1.0 References: <20201014005320.2233162-1-kaleshsingh@google.com> X-Mailer: git-send-email 2.28.0.1011.ga647a8990f-goog Subject: [PATCH v4 2/5] arm64: mremap speedup - Enable HAVE_MOVE_PMD From: Kalesh Singh Cc: surenb@google.com, minchan@google.com, joelaf@google.com, lokeshgidra@google.com, kaleshsingh@google.com, kernel-team@android.com, "Kirill A . Shutemov" , Catalin Marinas , Will Deacon , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Shuah Khan , Peter Zijlstra , Kees Cook , "Aneesh Kumar K.V" , Sami Tolvanen , Masahiro Yamada , Josh Poimboeuf , Frederic Weisbecker , Krzysztof Kozlowski , Hassan Naveed , Arnd Bergmann , Christian Brauner , Anshuman Khandual , Mark Brown , Gavin Shan , Mike Rapoport , Steven Price , Jia He , John Hubbard , Mike Kravetz , Greg Kroah-Hartman , Ram Pai , Mina Almasry , Ralph Campbell , Sandipan Das , Dave Hansen , Masami Hiramatsu , Jason Gunthorpe , Brian Geffon , SeongJae Park , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org HAVE_MOVE_PMD enables remapping pages at the PMD level if both the source and destination addresses are PMD-aligned. HAVE_MOVE_PMD is already enabled on x86. The original patch [1] that introduced this config did not enable it on arm64 at the time because of performance issues with flushing the TLB on every PMD move. These issues have since been addressed in more recent releases with improvements to the arm64 TLB invalidation and core mmu_gather code as Will Deacon mentioned in [2]. From the data below, it can be inferred that there is approximately 8x improvement in performance when HAVE_MOVE_PMD is enabled on arm64. --------- Test Results ---------- The following results were obtained on an arm64 device running a 5.4 kernel, by remapping a PMD-aligned, 1GB sized region to a PMD-aligned destination. The results from 10 iterations of the test are given below. All times are in nanoseconds. Control HAVE_MOVE_PMD 9220833 1247761 9002552 1219896 9254115 1094792 8725885 1227760 9308646 1043698 9001667 1101771 8793385 1159896 8774636 1143594 9553125 1025833 9374010 1078125 9100885.4 1134312.6 <-- Mean Time in nanoseconds Total mremap time for a 1GB sized PMD-aligned region drops from ~9.1 milliseconds to ~1.1 milliseconds. (~8x speedup). [1] https://lore.kernel.org/r/20181108181201.88826-3-joelaf@google.com [2] https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg140837.html Signed-off-by: Kalesh Singh Acked-by: Kirill A. Shutemov Cc: Catalin Marinas Cc: Will Deacon Cc: Andrew Morton --- Changes in v4: - Add Kirill's Acked-by. arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4b136e923ccb..434d6791e869 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -123,6 +123,7 @@ config ARM64 select GENERIC_VDSO_TIME_NS select HANDLE_DOMAIN_IRQ select HARDIRQS_SW_RESEND + select HAVE_MOVE_PMD select HAVE_PCI select HAVE_ACPI_APEI if (ACPI && EFI) select HAVE_ALIGNED_STRUCT_PAGE if SLUB