From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outbound.ms.icloud.com (p-west3-cluster6-host9-snip4-4.eps.apple.com [57.103.75.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B225E2D6409 for ; Fri, 1 May 2026 05:56:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=57.103.75.87 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777614978; cv=none; b=UlVPTXWbAmTGKj6AaKaBlFefiPanKbO4h/VXgLZLQBmM4zIQZLnkD1mAFgXAsH6ZLHd4xoGcObhloRJMdST5nvAc5Kceb2ZUcmV2FY9wunRgglbfQGerLy9Cu33Cm0Z+Ix8+1A4bhoqmj23PDMZKz0lvnWDXQ7EFJ/EG34HC0do= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777614978; c=relaxed/simple; bh=fe5qUdEup0HLb2HrLDxT1324Rwy5SIK9P92A+sggjFw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ClEzlnOiXdRCdTqFBH4DhuCswntKbqAYGvPWG8tUBCLZL3NrVKvGepOkoBNqEOmoYcU5j28uLXmDRbblKs8OB4+YHuwYPZr3GuEcl9Ui7mOxvkQT5AgSSrsDvCR6QMgCwDI0X8kDYzM8Jd/cgYSqghQoqmolAdvib+h5+geNBd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com; spf=pass smtp.mailfrom=icloud.com; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b=EwI+l9V3; arc=none smtp.client-ip=57.103.75.87 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=icloud.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b="EwI+l9V3" Received: from outbound.ms.icloud.com (unknown [127.0.0.2]) by p00-icloudmta-asmtp-us-west-3a-60-percent-8 (Postfix) with ESMTPS id B115A180013D; Fri, 01 May 2026 05:56:13 +0000 (UTC) X-ICL-Out-Info: HUtFAUMEWwJACUgBTUQeDx5WFlZNRAJCTQhAA0MFWgFeAUEdXwFLVxQEFEYGVg1dE0wLcwRUB10FXVZQAlpLVBQEFEYGVg1dE0wLcwRUB10FXVZQAlpLQBMESgZNXw5eHwQXRhlVBEceXVZeHhkCURxWDVdDVARfUEkMQVBsWgBHF0gdXRlZb1BdHA4EVAddBV1WUAJaS18ZXUUPXwdZBEAMSAJAQwNCL1oXREBBWh9DFEgDWARcBUQBSwReDytGFVcbVgNDRVEfVEYTGU4bV01QG18CQg8= Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1777614977; x=1780206977; bh=i/MDV/SdEyba8CAl8JXsfJJlaWhqdQgOiCYK9KUK3R4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:x-icloud-hme; b=EwI+l9V3Eq8DZJruLYfJo2dpxYir0zhLiB6TNlieOp7ifXH23lRVEDJC2EU/hq2wz3FO6ybNlfeB5udpXES9bVb4DDPjRx5qGhQeG0RGpS4aeYJlQVqt9gMmBBN+OMqNrOjOHmlA5zrDnza9xoLCQ3Zt37WtiivxOz+wlzcSE/lQsBRuRKtpOJa8Xve9bT7AyzxRExricclw1cf7QwdUFqYSbxqL27mRqA+uuLwh4JFiZvxAMyxdRzSXF29n50bgq85Gcp07zwj4wGta2LzNMkxiF8wkih1e//DMnTvkPyfovmUaHWPCPe6x3NrUb6QI6aD2R4Dxb0NFmsnDNoTkXQ== Received: from [127.0.0.1] (unknown [17.57.154.37]) by p00-icloudmta-asmtp-us-west-3a-60-percent-8 (Postfix) with ESMTPSA id DB5BF1800108; Fri, 01 May 2026 05:56:07 +0000 (UTC) From: Luka Bai Date: Fri, 01 May 2026 13:55:44 +0800 Subject: [PATCH 3/5] mm: add pmd level THP COW judgement helpers Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260501-thp_cow-v1-3-005377483738@tencent.com> References: <20260501-thp_cow-v1-0-005377483738@tencent.com> In-Reply-To: <20260501-thp_cow-v1-0-005377483738@tencent.com> To: linux-mm@kvack.org Cc: Jonathan Corbet , Shuah Khan , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Arnd Bergmann , Kairui Song , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, Luka Bai X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777614950; l=1685; i=lukabai@tencent.com; s=20260501; h=from:subject:message-id; bh=l3c8ZOwbATo+2PT4NYOAUghe4sk42dQjWN37S7JdcBg=; b=TSo2qM8r3KPPphClijLCEpGTnjI/pFC9+a8AQTQmdnuguNqhfa6BphAbJgkEVtcBJUMnH5Yi1 ukFPpvM8SE3DKy0cbu0hqLnkQgMtbzyqiZoO3sLbQG5tG9zz+vGRHPR X-Developer-Key: i=lukabai@tencent.com; a=ed25519; pk=KeaVteSWd00GIAjFyWZnuFsKAKixjga1ZkLMcI66nPM= X-Authority-Info-Out: v=2.4 cv=No3cssdJ c=1 sm=1 tr=0 ts=69f4407f cx=c_apl:c_pps:t_out a=qkKslKyYc0ctBTeLUVfTFg==:117 a=IkcTkHD0fZMA:10 a=NGcC8JguVDcA:10 a=x7bEGLp0ZPQA:10 a=UaoJkeuwEpQA:10 a=VkNPw1HP01LnGYTKEx00:22 a=GvQkQWPkAAAA:8 a=JogxrxylMUJFqwMgd1oA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: hB3IhlfY35IDEelkOKd30xeVKZ4dDTn9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTAxMDA1MyBTYWx0ZWRfX//GBnMBXJ+C+ gHIiUEpz5ykqv7rnL7hYpfRWgqfJ+r3gKMPEjydZWch8zDPRgnyic8lbsqmz7W3j9NORpehDbpm HKuQctCjN/YpeWJWQpUmbYiEkaC5JrIxyy1VYLmK2OeCTZUFp/ZJTLlnSzwEPF9GWO0BvAqBwZH 92Ej9piDwed/XU5gqf3lLyK9lyoPcVTUFAwXQRhq6IyviOvKDCRzX5nIdOLVel7x3tE0paAqprv knKjDu7zC5UVTLsD/eKxfTzl6wKAa+LQOLDzaRlo39GVGxC/5cSWeEIKnzNoLLM02pYqJyPLP3f NLHOvfOkNVMRy2QeQMYWg8GVvr1m0kohvEJxV0b1t4BN80PB9t1gM0vd7O3QsI= X-Proofpoint-GUID: hB3IhlfY35IDEelkOKd30xeVKZ4dDTn9 From: Luka Bai We add hugepage_cow_always and hugepage_cow_madvise as two convenient helpers to decide whether we want to do THP COW under each specific circumstance. Also, we add a helper hugepage_cow_enabled to help us know the setup more easily. THP COW is only opened when hugepage is globally enabled or madvise enabled. Signed-off-by: Luka Bai --- include/linux/huge_mm.h | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 2a62f0f92f68..3e5c6da3905b 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -203,6 +203,38 @@ static inline bool hugepage_global_always(void) (1<vm_flags; + + /* anonymous THP need to be enabled first */ + if (!hugepage_global_always() && + (!hugepage_global_enabled() || !(vm_flags & VM_HUGEPAGE))) + return false; + + /* always enables all the THP COW */ + if (hugepage_cow_always()) + return true; + + /* madvise enables THP cow only when vm_flags says so */ + if (hugepage_cow_madvise() && (vm_flags & VM_THP_COW)) + return true; + + return false; +} + static inline int highest_order(unsigned long orders) { return fls_long(orders) - 1; -- 2.52.0