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 2F813CAC5A5 for ; Thu, 25 Sep 2025 08:54:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 89E3F8E001E; Thu, 25 Sep 2025 04:54:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 875978E0001; Thu, 25 Sep 2025 04:54:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 764BD8E001E; Thu, 25 Sep 2025 04:54:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 6447B8E0001 for ; Thu, 25 Sep 2025 04:54:44 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 0C63E85CF6 for ; Thu, 25 Sep 2025 08:54:44 +0000 (UTC) X-FDA: 83927162088.18.6670E5B Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf04.hostedemail.com (Postfix) with ESMTP id 4805340005 for ; Thu, 25 Sep 2025 08:54:42 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=none; spf=pass (imf04.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1758790482; 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-transfer-encoding:content-transfer-encoding: in-reply-to:references; bh=+bHQorvdl2VGsXJwnvdwpUGu9FIfqf8vqwAgG8oXvIc=; b=05xERT9T01SQnF8V4t6V0418u3RzhwsuQNfnznaCGq3ff/QpdNo195tcYufsJFvP7j7fmR FTTb2G//CtRPUDyVs8q8TAtw4wu6o9SsGf7356ILgha2il76TOsiOzcaqoiDlM+Ot/MY63 gr4WYIjeOjmawszL/CHtIK90Mm7200k= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=none; spf=pass (imf04.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1758790482; a=rsa-sha256; cv=none; b=k+6uHeQgc8bc4IO2XbYxs5AwZbqqYkWwVai/9xkdWpkr0hbrg+1AgEZT3UB9Vin/EcUQNr sUJPTCTPlDMeAnAF58SvJEtLicuUXF3bMIdW0YM7UHjbjr1QrnrMMzSVYlh/rFTIc1KXjd CdMVlznh0fcuEg8i8Xq6MrUiOZwhv/c= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 147321692; Thu, 25 Sep 2025 01:54:33 -0700 (PDT) Received: from MacBook-Pro.blr.arm.com (MacBook-Pro.blr.arm.com [10.164.18.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 19A693F5A1; Thu, 25 Sep 2025 01:54:37 -0700 (PDT) From: Dev Jain To: akpm@linux-foundation.org, david@redhat.com Cc: lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dev Jain Subject: [PATCH] mm: move rmap of mTHP upon CoW reuse Date: Thu, 25 Sep 2025 14:24:29 +0530 Message-Id: <20250925085429.41607-1-dev.jain@arm.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4805340005 X-Stat-Signature: ipiucrtggt4uy1o94ny3cceyhf3auh7g X-HE-Tag: 1758790482-483656 X-HE-Meta: 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 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: At wp-fault time, when we find that a folio is exclusively mapped, we move folio->mapping to the faulting VMA's anon_vma, so that rmap overhead reduces. This is currently done for small folios (base pages) and PMD-mapped THPs. Do this for mTHP too. Signed-off-by: Dev Jain --- mm-selftests pass. mm/memory.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/memory.c b/mm/memory.c index 7e32eb79ba99..ec04d2cec6b1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4014,6 +4014,11 @@ static bool __wp_can_reuse_large_anon_folio(struct folio *folio, * an additional folio reference and never ended up here. */ exclusive = true; + + if (folio_trylock(folio)) { + folio_move_anon_rmap(folio, vma); + folio_unlock(folio); + } unlock: folio_unlock_large_mapcount(folio); return exclusive; -- 2.30.2