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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ECA8C2BD09 for ; Tue, 25 Jun 2024 01:19:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C1D296B00FE; Mon, 24 Jun 2024 21:19:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BCB406B0103; Mon, 24 Jun 2024 21:19:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A6BA06B010C; Mon, 24 Jun 2024 21:19:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 849D36B00FE for ; Mon, 24 Jun 2024 21:19:37 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 1158E12142E for ; Tue, 25 Jun 2024 01:19:37 +0000 (UTC) X-FDA: 82267653594.30.614941D Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) by imf03.hostedemail.com (Postfix) with ESMTP id E563820013 for ; Tue, 25 Jun 2024 01:19:33 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=icljNSq9; spf=pass (imf03.hostedemail.com: domain of ying.huang@intel.com designates 198.175.65.20 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1719278361; 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=B0qYsO04xaEHhvZjqIAYZJDpBSys8gou3Fa1HIfpxQA=; b=4p/DDQ/XGeoTsuTORcCwVBn4pAIZXU7ip/YECZ4fVXTV40ZyRXWrRc96cNtz02dXUaECpg mpMBBtLBzOWxC6o27Cn8TUvbFkfl85LbbLVzxMkVNfVX8/lafDlgdJdad1BXzfFZtODADP srYETRCp9ois2QQ+zGItTf6h4Ci4U5U= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1719278361; a=rsa-sha256; cv=none; b=vc9xHsz1bzfrwthF4rougA8wWVJuq/HQJu/NVwxyA7XQn+DNyg5lDVwBTkODFQCtaGWirV UvfhlqFOp5OXSCMLemsxRVOPwILJuC2kqzKF66VkGpyXxNZHD/Bt3UfXxEv/shwOyiBhIp aONvbfkzj/GuFwndVV29A3EOYCR7Ux4= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=icljNSq9; spf=pass (imf03.hostedemail.com: domain of ying.huang@intel.com designates 198.175.65.20 as permitted sender) smtp.mailfrom=ying.huang@intel.com; dmarc=pass (policy=none) header.from=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1719278375; x=1750814375; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=hl8DzPiMZFGRhrp1WZSG6/b29WAISU6j01dVgvMW95A=; b=icljNSq90qEa8tGZ8G9om8KPfjhQI/ZeJWUfiurDCCpZzKPzrCbeCuC8 b8Q6YvsGD+mAfkQn3DhXq8+JfhCH5NGPP6PNDlo8P/mPmvSvGirlsErX2 tvCLoIVMdQ4otkZbQ9/BqIY2J/ALrzg2wmt/8YSiX2Aug3LTRAWJmGXUx IPYqAYPbZ5QiHX0j2BaaVSGAgCTpuQd0bOdj8zYOrA3zzMHAimRBybLoj nnuH50ojJr5T3+/H2enLfezDh/b476XeeECpEUbT/9vyhsHvlAm5Jtgq9 ut9QD5XJy4f+EvXbWixHssPTTfqyNRIhFjw4itI1eZMqCfAvEb7lzYnyU w==; X-CSE-ConnectionGUID: ZKKJzXgzSR23Ej4QYg7Lqw== X-CSE-MsgGUID: VV0n4/JERsWok2SUhB1Szw== X-IronPort-AV: E=McAfee;i="6700,10204,11113"; a="16099687" X-IronPort-AV: E=Sophos;i="6.08,263,1712646000"; d="scan'208";a="16099687" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2024 18:19:33 -0700 X-CSE-ConnectionGUID: OMweji/PSgWk3WgZadzMEw== X-CSE-MsgGUID: 3boZ5J7tSkCy6+sc3RcnDg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,263,1712646000"; d="scan'208";a="48437550" Received: from unknown (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2024 18:19:31 -0700 From: "Huang, Ying" To: Zhenneng Li Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] migrate_pages: modify max number of pages to migrate in batch In-Reply-To: <20240624045120.121261-1-lizhenneng@kylinos.cn> (Zhenneng Li's message of "Mon, 24 Jun 2024 12:51:20 +0800") References: <20240624045120.121261-1-lizhenneng@kylinos.cn> Date: Tue, 25 Jun 2024 09:17:40 +0800 Message-ID: <87o77pzuq3.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: E563820013 X-Stat-Signature: 5ok9aojnumy8fxb3on1ks7875dyycx1o X-HE-Tag: 1719278373-557474 X-HE-Meta: U2FsdGVkX1//nvk7Q5LLlhd7j2rYmJL0fwohPYcoLD7u3cPs7VvStD02beBs1ZrZWgoGMtVdfYMu3xEqoRAmKe834MXs5I4cMIdCWpJqVJVK6KdUCPSITgLsBbWrDjZ6M+nFyNgH/IODEFMNn0MMuQ4gIKEq3m+qE2xFjFcwN4ufF3gJLDlTOVr9Gt62QkpJRP/rrxEUv82kPr5x1EzNVhjq5dwTe9m3uXAtOB6rpZCZ5yv/a16rLqd1SrzrVwoX7sZCPoy2JCn7nvB9RbcoyK6m+uSN905x3Se0BMAMRc5xnb39myaZ8pTywM60p+REMuUbNrqqU1vcAKWu3LgLQXELPhr6Vkw0y1KszIZ58aNCQSnxNBAEyhkk1Fi+sWGs8WYFmrZxw4brUhC6NKWo0xZQ7YLaAe1cC2v2hOu+Glay0ahZ1bbUfU9BbB9OyI9Ucp4BW5iXZwqEp/IB2JvZT35lT/4SiIXemEDp+nTBiMDgKRtmMPWinLffNkCbof82clgYERXL0HdNbEP2QYcrpm0cF7HIDu37RIDAhgfyr9txv0I3UjLu0Nua9Xs7AUfJF+kLXf3ToFIkgtJBterFOaBXHti/1hl+oL2FDHRD1T2AMiWytRgkvP4tYrnfcvqfTMVQyZvMiPsvCBmfX6O/eOg/dmy467GUPhtXjPmmR2oaExkYUPocHCgUxuowoEIAKZC/4DLRcC5Z4GW3bESASeoczotuSOv6iNoaJkvWIIu4Mviq/Tgp1PNZw65FYRapjvDwP/8nlTx9QeBLuLfI/2LDp96ce3ebU3YhFgmDcf4yu46hmPV5NvNtWJFlHe9JsS33XC1PyfXastr//Zuq8+L9yiSV9bNkNas6HbPzua1cgPhrpIWoS3y7qVnIn0elU0LXlzcUF+wjS8kELlaEPvUXx1zSvmQp5xRkdDNo+vv62UeJnoNaemXWCZFpDZHOAZ/sPeulJ7knUI2KrPW XC6ftdeo pJig5Tq44hHWeHniQzDtasp7JnoxNKfFXgrF1JFPTL7X9bC+VkgTsYAEjeyup6aHn+BVPsRyGV1ykQzDZgnhWk0kdzD1wQf+4D4DxoO/hKPCCMwX7WSoQyuY/zFOTxJq8+Fz8LvTqCxmBRnc7ACWVfP7BD/J1bJu2IjATeKg9SR7ig8Hh2Dvebqy3FIOOuOL429hV 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: Hi, Zhenneng, Zhenneng Li writes: > We restrict the number of pages to be migrated to no more than > HPAGE_PMD_NR or NR_MAX_BATCHED_MIGRATION, but in fact, the > number of pages to be migrated may reach 2*HPAGE_PMD_NR-1 or 2 > *NR_MAX_BATCHED_MIGRATION-1, it's not in inconsistent with the context. Yes. It's not HPAGE_PMD_NR exactly. > Please refer to the patch: 42012e0436d4(migrate_pages: restrict number > of pages to migrate in batch) > > Signed-off-by: Zhenneng Li > --- > mm/migrate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 781979567f64..7a4b37aac9e8 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1961,7 +1961,7 @@ int migrate_pages(struct list_head *from, new_folio_t get_new_folio, > break; > } > if (nr_pages >= NR_MAX_BATCHED_MIGRATION) > - list_cut_before(&folios, from, &folio2->lru); > + list_cut_before(&folios, from, &folio->lru); If the first entry of the list "from" is a THP with size HPAGE_PMD_NR, "folio" will be the first entry of from, so that "folios" will be empty. Right? > else > list_splice_init(from, &folios); > if (mode == MIGRATE_ASYNC) -- Best Regards, Huang, Ying