From nobody Sun Apr 12 00:02:31 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 3C0E5C19F2A for ; Thu, 4 Aug 2022 13:03:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232637AbiHDNDc (ORCPT ); Thu, 4 Aug 2022 09:03:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229988AbiHDNDb (ORCPT ); Thu, 4 Aug 2022 09:03:31 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59BCC2BED for ; Thu, 4 Aug 2022 06:03:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1659618210; x=1691154210; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=fjBaY/FwafB1AaXjG6rMcxtrVelzXUJzoU+isxw1T7E=; b=QXhRPgM+iJ7V5w5fTchgJA+NZtUVNyGLBC9lUdONzJWvDKn7B0hOLZy3 g509LxRJLNO5xvqkAo8ksBD4ph2HfOkxUj+rL0TzSNZNYaKpgrnLcgrOg HN6IBedTumilxVBKUQgO5ZECNSL4i2XR+YqAEvX1Xh/41ToqAVIx718Ne qPrJaZbmrqH8WQPOLWOs5CvQWUggYbBkPb+UQ7HA2MvD7w3pjhm4OHXWe YczJibXdFrmSf6MOPTusw4RJLs4yIeYCQW/4VYmbVBkehzlCz/Hp/pTUd KrVW6PdVGfXZHmRqxfSNPdJHqsNi7yD72qvC7sfcNB9HuPTXj5qSabewp A==; X-IronPort-AV: E=McAfee;i="6400,9594,10429"; a="270306449" X-IronPort-AV: E=Sophos;i="5.93,215,1654585200"; d="scan'208";a="270306449" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Aug 2022 06:03:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,215,1654585200"; d="scan'208";a="631576174" Received: from shbuild999.sh.intel.com ([10.239.147.181]) by orsmga008.jf.intel.com with ESMTP; 04 Aug 2022 06:03:13 -0700 From: Feng Tang To: Michal Hocko , Muchun Song , Mike Kravetz , Andrew Morton Cc: Dave Hansen , Ben Widawsky , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Feng Tang Subject: [PATCH] mm/hugetlb: add dedicated func to get 'allowed' nodemask for current process Date: Thu, 4 Aug 2022 21:03:42 +0800 Message-Id: <20220804130342.63355-1-feng.tang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: References: 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" Muchun Song found that after MPOL_PREFERRED_MANY policy was introduced in commit b27abaccf8e8 ("mm/mempolicy: add MPOL_PREFERRED_MANY for multiple= preferred nodes") [1], the policy_nodemask_current()'s semantics for this new policy has been changed, which returns 'preferred' nodes instead of 'allowed' nodes, and could hurt the usage of its caller in hugetlb: allowed_mems_nr(). Michal found the policy_nodemask_current() is only used by hugetlb, and suggested to move it to hugetlb code with more explicit name to enforce the 'allowed' semantics for which only MPOL_BIND policy matters. One note for the new policy_mbind_nodemask() is, the cross check from MPOL_BIND, gfp flags and cpuset configuration can lead to a no available node case, which is considered to be broken configuration, and 'NULL' (equals all nodes) will be returned. apply_policy_zone() is made extern to be called in hugetlb code and its return value is changed to bool. [1]. https://lore.kernel.org/lkml/20220801084207.39086-1-songmuchun@bytedan= ce.com/t/ Reported-by: Muchun Song Suggested-by: Michal Hocko Signed-off-by: Feng Tang Acked-by: Michal Hocko --- include/linux/mempolicy.h | 13 +------------ mm/hugetlb.c | 24 ++++++++++++++++++++---- mm/mempolicy.c | 2 +- 3 files changed, 22 insertions(+), 17 deletions(-) diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 668389b4b53d..d232de7cdc56 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -151,13 +151,6 @@ extern bool mempolicy_in_oom_domain(struct task_struct= *tsk, const nodemask_t *mask); extern nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy); =20 -static inline nodemask_t *policy_nodemask_current(gfp_t gfp) -{ - struct mempolicy *mpol =3D get_task_policy(current); - - return policy_nodemask(gfp, mpol); -} - extern unsigned int mempolicy_slab_node(void); =20 extern enum zone_type policy_zone; @@ -189,6 +182,7 @@ static inline bool mpol_is_preferred_many(struct mempol= icy *pol) return (pol->mode =3D=3D MPOL_PREFERRED_MANY); } =20 +extern bool apply_policy_zone(struct mempolicy *policy, enum zone_type zon= e); =20 #else =20 @@ -294,11 +288,6 @@ static inline void mpol_put_task_policy(struct task_st= ruct *task) { } =20 -static inline nodemask_t *policy_nodemask_current(gfp_t gfp) -{ - return NULL; -} - static inline bool mpol_is_preferred_many(struct mempolicy *pol) { return false; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index a18c071c294e..ad84bb85b6de 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4330,18 +4330,34 @@ static int __init default_hugepagesz_setup(char *s) } __setup("default_hugepagesz=3D", default_hugepagesz_setup); =20 +static nodemask_t *policy_mbind_nodemask(gfp_t gfp) +{ +#ifdef CONFIG_NUMA + struct mempolicy *mpol =3D get_task_policy(current); + + /* + * Only enforce MPOL_BIND policy which overlaps with cpuset policy + * (from policy_nodemask) specifically for hugetlb case + */ + if (mpol->mode =3D=3D MPOL_BIND && + (apply_policy_zone(mpol, gfp_zone(gfp)) && + cpuset_nodemask_valid_mems_allowed(&mpol->nodes))) + return &mpol->nodes; +#endif + return NULL; +} + static unsigned int allowed_mems_nr(struct hstate *h) { int node; unsigned int nr =3D 0; - nodemask_t *mpol_allowed; + nodemask_t *mbind_nodemask; unsigned int *array =3D h->free_huge_pages_node; gfp_t gfp_mask =3D htlb_alloc_mask(h); =20 - mpol_allowed =3D policy_nodemask_current(gfp_mask); - + mbind_nodemask =3D policy_mbind_nodemask(gfp_mask); for_each_node_mask(node, cpuset_current_mems_allowed) { - if (!mpol_allowed || node_isset(node, *mpol_allowed)) + if (!mbind_nodemask || node_isset(node, *mbind_nodemask)) nr +=3D array[node]; } =20 diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d39b01fd52fe..9f15bc533601 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1805,7 +1805,7 @@ bool vma_policy_mof(struct vm_area_struct *vma) return pol->flags & MPOL_F_MOF; } =20 -static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) +bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone) { enum zone_type dynamic_policy_zone =3D policy_zone; =20 --=20 2.27.0