From nobody Sun Feb 8 23:33:05 2026 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 17990EB64D7 for ; Wed, 21 Jun 2023 07:40:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231612AbjFUHkY (ORCPT ); Wed, 21 Jun 2023 03:40:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231718AbjFUHj6 (ORCPT ); Wed, 21 Jun 2023 03:39:58 -0400 Received: from chinatelecom.cn (prt-mail.chinatelecom.cn [42.123.76.226]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 62C3E170D for ; Wed, 21 Jun 2023 00:39:30 -0700 (PDT) HMM_SOURCE_IP: 172.18.0.218:48856.2131214271 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-36.111.64.85 (unknown [172.18.0.218]) by chinatelecom.cn (HERMES) with SMTP id A2234280099; Wed, 21 Jun 2023 15:39:22 +0800 (CST) X-189-SAVE-TO-SEND: +liuq131@chinatelecom.cn Received: from ([36.111.64.85]) by app0025 with ESMTP id 7601d43524a14bd38a38d662434cb33b for akpm@linux-foundation.org; Wed, 21 Jun 2023 15:39:25 CST X-Transaction-ID: 7601d43524a14bd38a38d662434cb33b X-Real-From: liuq131@chinatelecom.cn X-Receive-IP: 36.111.64.85 X-MEDUSA-Status: 0 Sender: liuq131@chinatelecom.cn From: liuq To: akpm@linux-foundation.org Cc: ying.huang@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, liuq Subject: [PATCH v2] mm/min_free_kbytes: modify min_free_kbytes calculation rules Date: Wed, 21 Jun 2023 15:39:12 +0800 Message-Id: <20230621073912.21747-1-liuq131@chinatelecom.cn> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The current calculation of min_free_kbytes only uses ZONE_DMA and ZONE_NORMAL pages,but the ZONE_MOVABLE zone->_watermark[WMARK_MIN] will also divide part of min_free_kbytes.This will cause the min watermark of ZONE_NORMAL to be too small in the presence of ZONE_MOVEABLE. __GFP_HIGH and PF_MEMALLOC allocations usually don't need moveable zone pages, so just like ZONE_HIGHMEM, cap pages_min to a small value in __setup_per_zone_wmarks. Signed-off-by: liuq --- mm/page_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 47421bedc12b..608384712a89 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6364,7 +6364,7 @@ static void __setup_per_zone_wmarks(void) =20 /* Calculate total number of !ZONE_HIGHMEM pages */ for_each_zone(zone) { - if (!is_highmem(zone)) + if (!is_highmem(zone) || zone_idx(zone) !=3D ZONE_MOVABLE) lowmem_pages +=3D zone_managed_pages(zone); } =20 @@ -6374,7 +6374,7 @@ static void __setup_per_zone_wmarks(void) spin_lock_irqsave(&zone->lock, flags); tmp =3D (u64)pages_min * zone_managed_pages(zone); do_div(tmp, lowmem_pages); - if (is_highmem(zone)) { + if (is_highmem(zone) || zone_idx(zone) =3D=3D ZONE_MOVABLE) { /* * __GFP_HIGH and PF_MEMALLOC allocations usually don't * need highmem pages, so cap pages_min to a small --=20 2.27.0