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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF46CFA3743 for ; Tue, 1 Nov 2022 06:22:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229907AbiKAGWp (ORCPT ); Tue, 1 Nov 2022 02:22:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229817AbiKAGWm (ORCPT ); Tue, 1 Nov 2022 02:22:42 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC8F515FC8 for ; Mon, 31 Oct 2022 23:22:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667283761; x=1698819761; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=FHNWw3yNYbnjvEUD6v5MeX3IamjwsD8jl6R6ZXAIZWg=; b=UyAkC0Ck9H15p5jGbZnhlv2BkjE5px+qlyKw8qsze7dOtt/UeR/KERkH qmHlexE9loKBvjowFRve77a9S6WYBAtapWcNVoE6qVxDk3GuMk1a+L/eY nYNnaYhi94zQy5zFkgYh+0Q/dOC8EUYn2nRxbMcTf1YbKsknacA2dn5Kl gSA+uRWGqLRByqGLVyqPmkV1oXZDiRnzR3BMZg9BFVgoEmxtz9NqdcG5Q thrME5G7MwIveljKVffSrihjsaerZPl3Wfwa3qiQfuHB62s6JUImpKlhw zp/qQfzoe8NiA6fweRiCkoaHwJpiwSZaCkaAfBlRl5uoXMu64ktUkiO8s w==; X-IronPort-AV: E=McAfee;i="6500,9779,10517"; a="395388675" X-IronPort-AV: E=Sophos;i="5.95,229,1661842800"; d="scan'208";a="395388675" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Oct 2022 23:22:41 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10517"; a="878998335" X-IronPort-AV: E=Sophos;i="5.95,229,1661842800"; d="scan'208";a="878998335" Received: from yhuang6-mobl2.sh.intel.com ([10.238.6.69]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Oct 2022 23:22:38 -0700 From: Huang Ying To: linux-mm@kvack.org Cc: Matthew Wilcox , linux-kernel@vger.kernel.org, Andrew Morton , Huang Ying , Zi Yan , Yang Shi , Baolin Wang , Oscar Salvador Subject: [RFC 0/2] migrate: convert migrate_pages()/unmap_and_move() to use folios Date: Tue, 1 Nov 2022 14:21:35 +0800 Message-Id: <20221101062137.83649-1-ying.huang@intel.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The conversion is quite straightforward, just replace the page API to the corresponding folio API. migrate_pages() and unmap_and_move() mostly work with folios (head pages) only. One question is about THP. Which is converted to large folio in the patchset. This is generally OK, because the code can work with arbitrary order large folio at most times. But some THP related statistics (such as THP_MIGRATION_SUCCESS, etc.) are converted for large folio with arbitrary order too. Do we really care about the order of large folio? Do we need to be backward compatible strictly? Best Regards, Huang, Ying