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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6109CAC59A for ; Wed, 17 Sep 2025 16:29:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EDB548E005A; Wed, 17 Sep 2025 12:29:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EB2D08E0002; Wed, 17 Sep 2025 12:29:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DEFB88E005A; Wed, 17 Sep 2025 12:29:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id D1D518E0002 for ; Wed, 17 Sep 2025 12:29:23 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 8B35B1DF522 for ; Wed, 17 Sep 2025 16:29:23 +0000 (UTC) X-FDA: 83899277406.26.8C798BB Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf07.hostedemail.com (Postfix) with ESMTP id CFDBE4000A for ; Wed, 17 Sep 2025 16:29:21 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="Efgoo/3O"; spf=pass (imf07.hostedemail.com: domain of acme@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=acme@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1758126562; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7zIZpqfsiZ4CVgJARmyKbDE6sDykkMIKdlIbnxDb4+Q=; b=C4tYM7/dOLfM7NkYRrE9OtaNa5duni+P4lSxXp2xnfavAGWI5/DdVQ7taxXZG7kvT2jvaC fP004psR3BzfQNkSMilWBKwZeeI7mKf7n0ROuBYmymXMtzoxJPSbOzrtznmsSMuEuAZ6UA eNz++Q5fp/LP/UIxUTmenX2lO/tWmnU= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="Efgoo/3O"; spf=pass (imf07.hostedemail.com: domain of acme@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=acme@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1758126562; a=rsa-sha256; cv=none; b=a4LXMYmTgF71dQxnzZc4bOtdf3N0sFFAp0EBtEPKJqjfxH/kqKQY0I3oKcFyFPJS4NmjoS 5z7a2Tqbjka2Df2xbXXsQ/w+dgFw4H/5Ii/yxDXC7c73cC8+hndbVmApJAUW/ylSPCwxZ2 Y9szVP0gHqS4CsVmEaCwpifPM9xyLwA= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id C7B6641821; Wed, 17 Sep 2025 16:29:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 591F7C4CEE7; Wed, 17 Sep 2025 16:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758126560; bh=2OcN4+QE4vB9KSX+x87Cdk3l913EKng1ECYM1XJ4iNY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Efgoo/3O0LeCmXH1rE1DrgEshaiVcNwoiGdG8gPR/qVy13CnvZhy67MLqQDbd1Nwu enTVAYHlzhaquq3xtN8aHEQJ43+ZMLVMdsXkEZIa+HcUfpRIV1k0dv2gdUGFQ4LcPp MLXKrgn89SIv2BNKLnINxK6b+AQdHaO1/9YvsrzW1bPzB0zZ+PH9NwTAvEnOWPivsk e1H/U0OCmG9hQDwRJ7dblDd0FZeTJpXJgS/cWqhzztqV2KHa56zWXi5lbfUt7zGwOX qsfIETUK9/JSo5CI5A/DO3GDqdyjekXMCAuVzOxn4Llo0FK3St0PJRf7PEYyzQJCps sptrXw5WzO+QA== Date: Wed, 17 Sep 2025 13:29:18 -0300 From: Arnaldo Carvalho de Melo To: Ankur Arora Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, david@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org, namhyung@kernel.org, tglx@linutronix.de, willy@infradead.org, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com Subject: Re: [PATCH v7 00/16] mm: folio_zero_user: clear contiguous pages Message-ID: References: <20250917152418.4077386-1-ankur.a.arora@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250917152418.4077386-1-ankur.a.arora@oracle.com> X-Stat-Signature: h6ix6z6n3wccwwkymbqphqyu5y36tx5e X-Rspam-User: X-Rspamd-Queue-Id: CFDBE4000A X-Rspamd-Server: rspam04 X-HE-Tag: 1758126561-725569 X-HE-Meta: U2FsdGVkX1+NRmmkqzcyT7hi0SrpitlYqLqku93+p/UJioxu09UgIopS/EtFXm9CGwt1Yr+HpN7ZboXjMvwzy3BZU05cy9svValul1/vZAqK3V4b8YbvJQjGMp1+c/m/95HagE71zbYyNYHqu/RmMtPJLRiAvnxe/xys06e13Kx5Z0qy1uQcZ8qdKcDhFo0oNgcsR9jH51PCKg58S7e1hcVAWb4LrlLbZ7wU/qx39vlBORMEh6MYgtN+qzipF4Yq+X0LyrHLguZ/DzAU6oZif/fsxJyi1ujujRrKXbbMqJ5iJw2958W1CgXDn50mFhjQQ0G8/OBym8FL/X4A1pgJs6dB5UtHbAiMUXanNNx5KOHLJbmHvuWRfNw8FYoTmnkieGBaa67iQU/96oN6LYW2aArZPEgJdJ8wuYv54rPiHsR+gFrNMiuz77WVWyzZqeUHx3j06MCWhH9Kr18F+pt1y2ENHcq3qJ0BH8PfjniM3+F0ab4EtR8E+tbauq+LasRLoReDni2Lfyvn20fbbvIPzfKyjBSjs1TT1hWMilo2f5WZw89wOcUiNz84Bincby0SgwRU5wcDXBqWErkZEFaj4uPpdh5qkRqzFJlQNpBd0b6Rwiejdeb9KmDB+lXUm1WBmf6787yZr8I9wiUoWhCL0u5QQa9q0KFxekd9SS3BPIIErIa9rFjDP9RKzGLEdANqNg1erMR9VsdkrZ/h7/8nCuoKP0q6q8WLODU4bN3c3JxdWFmdESDVRHZmyoP2KphNrn1pQm4dTvtUBJsEa/3jVbepev+gG9yzvYFBkhSKKStNwuuXznRvTxQ1n6iS9W7R0nyOUpuuGTNyT6gork5JR3gAxaOelfaqyN6cFYQ4Gj+rb180g19TdFmFhcH7vruR8UPFFiXKE2Qn5fp/BehfoKkEmLt6CwqrDkzrFQKW+Lt0VsyVwiLxL6DqjGl3g6cKpI+BiosC9Vnrt6mJqAW EhxNYRBr EepWSMce7lzV9W624fPhQKSLoAVc1wQdGaIqggWx/lw8S+fSyovWZVkCnygiff4SOWYxLBy6H6Is7lb3Lex1kNuefRLGkM2Bb9N1no3JcQsExTgAo9WRaX7BY5PpVRZYijuoJ0agzLRoC7tIjvNW6Wdy+1MK/pZIZU6cAcXNIAHZ428qKyPvB+UWB7Gq9eRuskLyvO/qKpX2wA0RY6OQD7NgLCpYlLX3dBx6sxCQkDzRHJb07cAdudOTCsQdMQwIPjET138EW3v9rMtV141Lz26eNzWs+9911xpG3NGWDUNaUc8q1iM44it7F5z4N+WDEzoYmj4vD5JaZH1i9UFvKHuwWFupktyiV/jmxqbDaKm+G+SREVUimprYCYJlMEPIkvMEvr/Aj6Pxq4+I= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Sep 17, 2025 at 08:24:02AM -0700, Ankur Arora wrote: > This series adds clearing of contiguous page ranges for hugepages, > improving on the current page-at-a-time approach in two ways: > > - amortizes the per-page setup cost over a larger extent > > - when using string instructions, exposes the real region size > to the processor. > > A processor could use a knowledge of the extent to optimize the > clearing. AMD Zen uarchs, as an example, elide allocation of > cachelines for regions larger than L3-size. > > Demand faulting a 64GB region shows performance improvements: > > $ perf bench mem map -p $pg-sz -f demand -s 64GB -l 5 > > mm/folio_zero_user x86/folio_zero_user change > (GB/s +- %stdev) (GB/s +- %stdev) > > pg-sz=2MB 11.82 +- 0.67% 16.48 +- 0.30% + 39.4% preempt=* > > pg-sz=1GB 17.14 +- 1.39% 17.42 +- 0.98% [#] + 1.6% preempt=none|voluntary > pg-sz=1GB 17.51 +- 1.19% 43.23 +- 5.22% +146.8% preempt=full|lazy > > [#] Milan uses a threshold of LLC-size (~32MB) for eliding cacheline > allocation, which is higher than the maximum extent used on x86 > (ARCH_CONTIG_PAGE_NR=8MB), so preempt=none|voluntary sees no improvement > with pg-sz=1GB. I'm picking up the tools/perf part for perf-tools-next (v6.18), already almost 100% reviewed by Namhyung. Thanks, - Arnaldo > Raghavendra also tested v3/v4 on AMD Genoa and sees similar improvements [1]. > > Changelog: > > v7: > - interface cleanups, comments for clear_user_highpages(), clear_user_pages(), > clear_pages(). > - fixed build errors flagged by kernel test robot > - move all x86 patches to the tail end > > v6: > - perf bench mem: update man pages and other cleanups (Namhyung Kim) > - unify folio_zero_user() for HIGHMEM, !HIGHMEM options instead of > working through a new config option (David Hildenbrand). > - cleanups and simlification around that. > (https://lore.kernel.org/lkml/20250902080816.3715913-1-ankur.a.arora@oracle.com/) > > v5: > - move the non HIGHMEM implementation of folio_zero_user() from x86 > to common code (Dave Hansen) > - Minor naming cleanups, commit messages etc > (https://lore.kernel.org/lkml/20250710005926.1159009-1-ankur.a.arora@oracle.com/) > > v4: > - adds perf bench workloads to exercise mmap() populate/demand-fault (Ingo) > - inline stosb etc (PeterZ) > - handle cooperative preemption models (Ingo) > - interface and other cleanups all over (Ingo) > (https://lore.kernel.org/lkml/20250616052223.723982-1-ankur.a.arora@oracle.com/) > > v3: > - get rid of preemption dependency (TIF_ALLOW_RESCHED); this version > was limited to preempt=full|lazy. > - override folio_zero_user() (Linus) > (https://lore.kernel.org/lkml/20250414034607.762653-1-ankur.a.arora@oracle.com/) > > v2: > - addressed review comments from peterz, tglx. > - Removed clear_user_pages(), and CONFIG_X86_32:clear_pages() > - General code cleanup > (https://lore.kernel.org/lkml/20230830184958.2333078-1-ankur.a.arora@oracle.com/) > > Comments appreciated! > > Also at: > github.com/terminus/linux clear-pages.v7 > > [1] https://lore.kernel.org/lkml/fffd4dad-2cb9-4bc9-8a80-a70be687fd54@amd.com/ > > Ankur Arora (16): > perf bench mem: Remove repetition around time measurement > perf bench mem: Defer type munging of size to float > perf bench mem: Move mem op parameters into a structure > perf bench mem: Pull out init/fini logic > perf bench mem: Switch from zalloc() to mmap() > perf bench mem: Allow mapping of hugepages > perf bench mem: Allow chunking on a memory region > perf bench mem: Refactor mem_options > perf bench mem: Add mmap() workloads > mm: define clear_pages(), clear_user_pages() > mm/highmem: introduce clear_user_highpages() > arm: mm: define clear_user_highpages() > mm: memory: support clearing page ranges > x86/mm: Simplify clear_page_* > x86/clear_page: Introduce clear_pages() > x86/clear_pages: Support clearing of page-extents > > arch/arm/include/asm/page.h | 7 + > arch/x86/include/asm/page_32.h | 6 + > arch/x86/include/asm/page_64.h | 72 +++- > arch/x86/lib/clear_page_64.S | 39 +- > include/linux/highmem.h | 18 + > include/linux/mm.h | 44 +++ > mm/memory.c | 82 +++- > tools/perf/Documentation/perf-bench.txt | 58 ++- > tools/perf/bench/bench.h | 1 + > tools/perf/bench/mem-functions.c | 390 ++++++++++++++----- > tools/perf/bench/mem-memcpy-arch.h | 2 +- > tools/perf/bench/mem-memcpy-x86-64-asm-def.h | 4 + > tools/perf/bench/mem-memset-arch.h | 2 +- > tools/perf/bench/mem-memset-x86-64-asm-def.h | 4 + > tools/perf/builtin-bench.c | 1 + > 15 files changed, 560 insertions(+), 170 deletions(-) > > -- > 2.43.5