From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 28526C47DD9 for ; Mon, 22 Jan 2024 19:43:12 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=dghOIczA; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=dghOIczA; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TJgcZ3h82z3cTx for ; Tue, 23 Jan 2024 06:43:10 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=dghOIczA; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=dghOIczA; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=170.10.129.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=david@redhat.com; receiver=lists.ozlabs.org) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4TJgbc5rP9z3bmN for ; Tue, 23 Jan 2024 06:42:17 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705952535; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=qd9zQc8SwlMxJsbzyQie1UqPu3p8Wk+b2U2cDU4I5Gw=; b=dghOIczAf3yPvGXARla7b+OiBLmzGUEvk+iDeFxd4UnNffD5kp8ljtdCrnOpw5dPPN2hZ1 14HMYugEjPCA5PiCqCzLlnvJFM2zGfElX5I9zEIQLJYKmgtBw6eolrB/yYk3ppAXSMn2y9 ffnCtodP7s8oVYnuDvIuJadeAyuXzs0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705952535; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=qd9zQc8SwlMxJsbzyQie1UqPu3p8Wk+b2U2cDU4I5Gw=; b=dghOIczAf3yPvGXARla7b+OiBLmzGUEvk+iDeFxd4UnNffD5kp8ljtdCrnOpw5dPPN2hZ1 14HMYugEjPCA5PiCqCzLlnvJFM2zGfElX5I9zEIQLJYKmgtBw6eolrB/yYk3ppAXSMn2y9 ffnCtodP7s8oVYnuDvIuJadeAyuXzs0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-351-x69pe3DCPsqpnwDc2t8HtA-1; Mon, 22 Jan 2024 14:42:11 -0500 X-MC-Unique: x69pe3DCPsqpnwDc2t8HtA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AEEA788D016; Mon, 22 Jan 2024 19:42:09 +0000 (UTC) Received: from t14s.redhat.com (unknown [10.39.195.114]) by smtp.corp.redhat.com (Postfix) with ESMTP id 267043C2E; Mon, 22 Jan 2024 19:42:02 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Subject: [PATCH v1 00/11] mm/memory: optimize fork() with PTE-mapped THP Date: Mon, 22 Jan 2024 20:41:49 +0100 Message-ID: <20240122194200.381241-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , Catalin Marinas , linux-mm@kvack.org, sparclinux@vger.kernel.org, Alexander Gordeev , Will Deacon , linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Russell King , Matthew Wilcox , "Aneesh Kumar K.V" , "Naveen N. Rao" , Gerald Schaefer , Christian Borntraeger , Albert Ou , Ryan Roberts , Vasily Gorbik , Heiko Carstens , Nicholas Piggin , Paul Walmsley , linux-arm-kernel@lists.infradead.org, Dinh Nguyen , Palmer Dabbelt , Sven Schnelle , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Now that the rmap overhaul[1] is upstream that provides a clean interface for rmap batching, let's implement PTE batching during fork when processing PTE-mapped THPs. This series is partially based on Ryan's previous work[2] to implement cont-pte support on arm64, but its a complete rewrite based on [1] to optimize all architectures independent of any such PTE bits, and to use the new rmap batching functions that simplify the code and prepare for further rmap accounting changes. We collect consecutive PTEs that map consecutive pages of the same large folio, making sure that the other PTE bits are compatible, and (a) adjust the refcount only once per batch, (b) call rmap handling functions only once per batch and (c) perform batch PTE setting/updates. While this series should be beneficial for adding cont-pte support on ARM64[2], it's one of the requirements for maintaining a total mapcount[3] for large folios with minimal added overhead and further changes[4] that build up on top of the total mapcount. Independent of all that, this series results in a speedup during fork with PTE-mapped THP, which is the default with THPs that are smaller than a PMD (for example, 16KiB to 1024KiB mTHPs for anonymous memory[5]). On an Intel Xeon Silver 4210R CPU, fork'ing with 1GiB of PTE-mapped folios of the same size (stddev < 1%) results in the following runtimes for fork() (shorter is better): Folio Size | v6.8-rc1 | New | Change ------------------------------------------ 4KiB | 0.014328 | 0.014265 | 0% 16KiB | 0.014263 | 0.013293 | - 7% 32KiB | 0.014334 | 0.012355 | -14% 64KiB | 0.014046 | 0.011837 | -16% 128KiB | 0.014011 | 0.011536 | -18% 256KiB | 0.013993 | 0.01134 | -19% 512KiB | 0.013983 | 0.011311 | -19% 1024KiB | 0.013986 | 0.011282 | -19% 2048KiB | 0.014305 | 0.011496 | -20% Next up is PTE batching when unmapping, that I'll probably send out based on this series this/next week. Only tested on x86-64. Compile-tested on most other architectures. Will do more testing and double-check the arch changes while this is getting some review. [1] https://lkml.kernel.org/r/20231220224504.646757-1-david@redhat.com [2] https://lkml.kernel.org/r/20231218105100.172635-1-ryan.roberts@arm.com [3] https://lkml.kernel.org/r/20230809083256.699513-1-david@redhat.com [4] https://lkml.kernel.org/r/20231124132626.235350-1-david@redhat.com [5] https://lkml.kernel.org/r/20231207161211.2374093-1-ryan.roberts@arm.com Cc: Andrew Morton Cc: Matthew Wilcox (Oracle) Cc: Ryan Roberts Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Dinh Nguyen Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: "Aneesh Kumar K.V" Cc: "Naveen N. Rao" Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Alexander Gordeev Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Sven Schnelle Cc: "David S. Miller" Cc: linux-arm-kernel@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: sparclinux@vger.kernel.org David Hildenbrand (11): arm/pgtable: define PFN_PTE_SHIFT on arm and arm64 nios2/pgtable: define PFN_PTE_SHIFT powerpc/pgtable: define PFN_PTE_SHIFT risc: pgtable: define PFN_PTE_SHIFT s390/pgtable: define PFN_PTE_SHIFT sparc/pgtable: define PFN_PTE_SHIFT mm/memory: factor out copying the actual PTE in copy_present_pte() mm/memory: pass PTE to copy_present_pte() mm/memory: optimize fork() with PTE-mapped THP mm/memory: ignore dirty/accessed/soft-dirty bits in folio_pte_batch() mm/memory: ignore writable bit in folio_pte_batch() arch/arm/include/asm/pgtable.h | 2 + arch/arm64/include/asm/pgtable.h | 2 + arch/nios2/include/asm/pgtable.h | 2 + arch/powerpc/include/asm/pgtable.h | 2 + arch/riscv/include/asm/pgtable.h | 2 + arch/s390/include/asm/pgtable.h | 2 + arch/sparc/include/asm/pgtable_64.h | 2 + include/linux/pgtable.h | 17 ++- mm/memory.c | 188 +++++++++++++++++++++------- 9 files changed, 173 insertions(+), 46 deletions(-) base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d -- 2.43.0