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 96EA0FD2D73 for ; Tue, 10 Mar 2026 13:00:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BED4F6B0088; Tue, 10 Mar 2026 09:00:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BC5046B008A; Tue, 10 Mar 2026 09:00:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD16C6B0098; Tue, 10 Mar 2026 09:00:10 -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 9D8086B0088 for ; Tue, 10 Mar 2026 09:00:10 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 3DA28138DBE for ; Tue, 10 Mar 2026 13:00:10 +0000 (UTC) X-FDA: 84530161380.12.8D52BF8 Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) by imf09.hostedemail.com (Postfix) with ESMTP id 46BD1140006 for ; Tue, 10 Mar 2026 13:00:08 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CU4iyxRk; spf=pass (imf09.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1773147608; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=RftT2Y3IHSXVZYJ/UW0Tv3eAsLcm29Tj9tutyIZqu1o=; b=qNReTS2BeFLL9B7ogMHGW/qBHJyv5mgGPGqM5UiLIwx6A6/ASq6MFS/RKqGeV06O1mGKNY Hkpxtkq0hAskmO77JYcMLCk2rRoM+Netvk4cIwe46hHMdzauZK+tRAoA4MQ3SiFAgmQZHn glmlqLavlCZjqX83YyKq/e1m1g4Ua/s= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CU4iyxRk; spf=pass (imf09.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1773147608; a=rsa-sha256; cv=none; b=SUTdmmVmJisAeUIuttlMEbjGm++Ful+RqU3FmAuHP3mLwUEsHCFRdvACtfTUqDUzOTHGGI EnXQa7dHStjzjC1XlMMsqs6y6W9tAddIy8uvibQdpuZph9ZtCNmXEsOe0vl6BHp8h4IWr9 XgZVvl9B4ngn5NUEhNqzekyhRub0tfc= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773147605; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RftT2Y3IHSXVZYJ/UW0Tv3eAsLcm29Tj9tutyIZqu1o=; b=CU4iyxRkqkOC9/RWtWv+LAXeUNmQxDABlgtj4YJbm6UgHanX2RC8TMubw3qTTXydh02zku 6CI+w51oyp132mrx6nNaEog5MHpNDZFpwyNJcwjN1iMFnEqSSB2q8AhbsiZdTJ6v1HYvFI 2KD7n6dcSjrzxsZPydIqyn5R/lh+p88= From: Lance Yang To: dev.jain@arm.com Cc: Liam.Howlett@oracle.com, akpm@linux-foundation.org, anshuman.khandual@arm.com, axelrasmussen@google.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, bhe@redhat.com, chrisl@kernel.org, david@kernel.org, harry.yoo@oracle.com, hughd@google.com, jannh@google.com, kas@kernel.org, kasong@tencent.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, mhocko@suse.com, nphamcs@gmail.com, pfalcato@suse.de, riel@surriel.com, rppt@kernel.org, ryan.roberts@arm.com, shikemeng@huaweicloud.com, surenb@google.com, vbabka@kernel.org, weixugc@google.com, willy@infradead.org, youngjun.park@lge.com, yuanchu@google.com, yuzhao@google.com, ziy@nvidia.com, Lance Yang Subject: Re: [PATCH 0/9] mm/rmap: Optimize anonymous large folio unmapping Date: Tue, 10 Mar 2026 20:59:40 +0800 Message-ID: <20260310125940.39707-1-lance.yang@linux.dev> In-Reply-To: <20260310073013.4069309-1-dev.jain@arm.com> References: <20260310073013.4069309-1-dev.jain@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: rp6ea4en398hnjbg9ttajhicxo5jkq1u X-Rspamd-Server: rspam09 X-Rspam-User: X-Rspamd-Queue-Id: 46BD1140006 X-HE-Tag: 1773147608-803823 X-HE-Meta: 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 lu63ikE8 gp/D3ZlA0p1XATCew3JOjIZS+qTvLnQPD/aqyFFCn3wWxWPrpQQEV30ZLDKDmf1871lwjDO2iisRHCL6PhTtqr9cOxqFGc2IB11WFOKnJAcU9BFe8lWW/Bj0Y2e+bTES9p5CEIVHRrkKtmkft7yJbWD5s7OScCHtRFidIgO9Lzffnw5k0j7DnO5UyaBwBo88rR/iMB0zKfQWKV3bTkYoPQrddAg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Mar 10, 2026 at 01:00:04PM +0530, Dev Jain wrote: >Speed up unmapping of anonymous large folios by clearing the ptes, and >setting swap ptes, in one go. > >The following benchmark (stolen from Barry at [1]) is used to measure the >time taken to swapout 256M worth of memory backed by 64K large folios: > > #define _GNU_SOURCE > #include > #include > #include > #include > #include > #include > #include > > #define SIZE_MB 256 > #define SIZE_BYTES (SIZE_MB * 1024 * 1024) > > int main() { > void *addr = mmap(NULL, SIZE_BYTES, PROT_READ | PROT_WRITE, > MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); > if (addr == MAP_FAILED) { > perror("mmap failed"); > return 1; > } > > memset(addr, 0, SIZE_BYTES); > > struct timespec start, end; > clock_gettime(CLOCK_MONOTONIC, &start); > > if (madvise(addr, SIZE_BYTES, MADV_PAGEOUT) != 0) { > perror("madvise(MADV_PAGEOUT) failed"); > munmap(addr, SIZE_BYTES); > return 1; > } > > clock_gettime(CLOCK_MONOTONIC, &end); > > long duration_ns = (end.tv_sec - start.tv_sec) * 1e9 + > (end.tv_nsec - start.tv_nsec); > printf("madvise(MADV_PAGEOUT) took %ld ns (%.3f ms)\n", > duration_ns, duration_ns / 1e6); > > munmap(addr, SIZE_BYTES); > return 0; > } > >On arm64, only showing one of the middle values in the distribution: > >without patch: >madvise(MADV_PAGEOUT) took 52192959 ns (52.193 ms) > >with patch: >madvise(MADV_PAGEOUT) took 26676625 ns (26.677 ms) Good numbers! Just tested on x86 KVM with THP=never, no performance regression observed. Cheers, Lance