From patchwork Wed Sep 21 22:36:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Berger X-Patchwork-Id: 12984274 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 6D5EFC32771 for ; Wed, 21 Sep 2022 22:37:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 062416B0072; Wed, 21 Sep 2022 18:37:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0129F80008; Wed, 21 Sep 2022 18:37:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF5666B0074; Wed, 21 Sep 2022 18:37:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id D1A1B6B0072 for ; Wed, 21 Sep 2022 18:37:17 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id AC523A0185 for ; Wed, 21 Sep 2022 22:37:17 +0000 (UTC) X-FDA: 79937554914.22.D839E01 Received: from mail-qk1-f178.google.com (mail-qk1-f178.google.com [209.85.222.178]) by imf27.hostedemail.com (Postfix) with ESMTP id 5F8C74000B for ; Wed, 21 Sep 2022 22:37:17 +0000 (UTC) Received: by mail-qk1-f178.google.com with SMTP id k12so5031701qkj.8 for ; Wed, 21 Sep 2022 15:37:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=W65OPn/JICs8j0QopHJv5kNae6yu6rzXZKtwjhKQdDM=; b=BJt7G/2c59nwBSk8Q0V3/7HnKDO6LesViA0xuVg+AKKCX+h2EeeBYkeXg6TsoAjlVC Kib+ror8qjzjovAiAcLv1qxgl61JtBdSuWNin5zR6mKlz5IaSzErcjv/YpMPdKimVqk9 V6p0PisB7NFwu+6MsTMW0YBvCWFQ6g+5q/GnTMHJzHvw2ZxG+o1Aa4b6LHlvAWogYl/S Hr4kS8K6rhVR6CSn5aeSA0GnQKzcFVoawtIeiRgdn6w+ONR+upm/zFSZI7s5R9zcI7iV fFAN2mAfWX1wHgNMjY+Xen1iIvDy1Wd8PQkGAnIihgOh6KtFnNxdX7iQmG+ZNvQfEhmm IJZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=W65OPn/JICs8j0QopHJv5kNae6yu6rzXZKtwjhKQdDM=; b=k23wii1F1BSzYcqzkYyhdaUgtdT4QlEYx2+TamXdJlQNAhZjb05YatIPqLpRdDK6MR cOZRiJZxkt60RXxFk2+oPFHnyRaftAwqA04AiWMsLoWlcgoiANHzxbq6PlhRA4BxSo5/ JbtN721MqT8G/uEmstlYEcduJnSKvfPU9px9RMFLM7yfVJ8bIg/uz4C9nrCYqO8WdSXT P8tsoDvJbfCZysTQcymHUtj/8LdVdNRuHLSGioFkcuAZQ7AvqFf4aKtatu/8ULG4e5G+ pi/T6cierrI9SIQ7cHd0T8hfhd6HwlyG6rKCJB5cKCjm/DlTEgq509G2ak9qrzP8+7ju O7Ww== X-Gm-Message-State: ACrzQf0Gjj+F6rKT7kp+NUg0XjAQp5FeuoOjcGnMLg909X6EdnJC/PnA N0jiDeNPQFHAXkH6JsTwvAP0oihUDQk= X-Google-Smtp-Source: AMsMyM7dWSkzW1KyqoUVlKGHvNPTSTszHVZixiUm4p91nyjOSPM1g3zSIZHi3b8z8mqKUFlf+7gJoQ== X-Received: by 2002:a05:620a:254e:b0:6c9:cc85:c41a with SMTP id s14-20020a05620a254e00b006c9cc85c41amr275973qko.260.1663799836698; Wed, 21 Sep 2022 15:37:16 -0700 (PDT) Received: from stbirv-lnx-3.igp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id j13-20020a05620a288d00b006cea2984c9bsm2731540qkp.100.2022.09.21.15.37.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Sep 2022 15:37:14 -0700 (PDT) From: Doug Berger To: Andrew Morton Cc: Mike Kravetz , Muchun Song , Florian Fainelli , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Doug Berger Subject: [PATCH 1/3] mm/hugetlb: refactor alloc_and_dissolve_huge_page Date: Wed, 21 Sep 2022 15:36:37 -0700 Message-Id: <20220921223639.1152392-2-opendmb@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220921223639.1152392-1-opendmb@gmail.com> References: <20220921223639.1152392-1-opendmb@gmail.com> MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663799837; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=W65OPn/JICs8j0QopHJv5kNae6yu6rzXZKtwjhKQdDM=; b=F+XKKpJ/XGWwNRFR7H1Hk2BSd2bkYsZt1tMIoO2kZ/AAWtgBaCZDXjkrwDTmyE5xpZOld5 brCPyGaU49fMV5Nd/Qi18c+Rgd8XwDHhTdfbv3y5mT/LTtpbTdX779Zkzpps0kGDyK4ZDO yk/8zMxtR+TW9+eKTcyEf1zJJtt76zk= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b="BJt7G/2c"; spf=pass (imf27.hostedemail.com: domain of opendmb@gmail.com designates 209.85.222.178 as permitted sender) smtp.mailfrom=opendmb@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663799837; a=rsa-sha256; cv=none; b=VsBhxUfZgNJDJ3Wm45PxBmb824UQogYclM0UszJBpOUPyat2EnDqEn2Fnlsn3BoKvTO+cm KfTHL6ojzsyEYZfQgYQgPoI4fcPLGS2XzUVzcPpg2cWFuve8Z9fxJGfrUhQgo51S0VTBhJ 0QSi7dGS1l4wsjYk66okWrbupqqreTs= Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b="BJt7G/2c"; spf=pass (imf27.hostedemail.com: domain of opendmb@gmail.com designates 209.85.222.178 as permitted sender) smtp.mailfrom=opendmb@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Stat-Signature: xi8eidppfoe6d6bctnm8pr3ahz7s7y78 X-Rspamd-Queue-Id: 5F8C74000B X-Rspam-User: X-Rspamd-Server: rspam12 X-HE-Tag: 1663799837-607468 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: The alloc_replacement_page() and replace_hugepage() functions are created from code in the alloc_and_dissolve_huge_page() function to allow their reuse by the next commit. Signed-off-by: Doug Berger --- mm/hugetlb.c | 84 +++++++++++++++++++++++++++++++--------------------- 1 file changed, 51 insertions(+), 33 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e070b8593b37..2b60de78007c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2709,32 +2709,22 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma, } /* - * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one - * @h: struct hstate old page belongs to - * @old_page: Old page to dissolve - * @list: List to isolate the page in case we need to - * Returns 0 on success, otherwise negated error. + * Before dissolving the page, we need to allocate a new one for the + * pool to remain stable. Here, we allocate the page and 'prep' it + * by doing everything but actually updating counters and adding to + * the pool. This simplifies and let us do most of the processing + * under the lock. */ -static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, - struct list_head *list) +static struct page *alloc_replacement_page(struct hstate *h, int nid) { gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE; - int nid = page_to_nid(old_page); bool alloc_retry = false; struct page *new_page; - int ret = 0; - /* - * Before dissolving the page, we need to allocate a new one for the - * pool to remain stable. Here, we allocate the page and 'prep' it - * by doing everything but actually updating counters and adding to - * the pool. This simplifies and let us do most of the processing - * under the lock. - */ alloc_retry: new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL); if (!new_page) - return -ENOMEM; + return ERR_PTR(-ENOMEM); /* * If all goes well, this page will be directly added to the free * list in the pool. For this the ref count needs to be zero. @@ -2748,7 +2738,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, SetHPageTemporary(new_page); if (!put_page_testzero(new_page)) { if (alloc_retry) - return -EBUSY; + return ERR_PTR(-EBUSY); alloc_retry = true; goto alloc_retry; @@ -2757,6 +2747,48 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, __prep_new_huge_page(h, new_page); + return new_page; +} + +static void replace_hugepage(struct hstate *h, int nid, struct page *old_page, + struct page *new_page) +{ + lockdep_assert_held(&hugetlb_lock); + /* + * Ok, old_page is still a genuine free hugepage. Remove it from + * the freelist and decrease the counters. These will be + * incremented again when calling __prep_account_new_huge_page() + * and enqueue_huge_page() for new_page. The counters will remain + * stable since this happens under the lock. + */ + remove_hugetlb_page(h, old_page, false); + + /* + * Ref count on new page is already zero as it was dropped + * earlier. It can be directly added to the pool free list. + */ + __prep_account_new_huge_page(h, nid); + enqueue_huge_page(h, new_page); +} + +/* + * alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one + * @h: struct hstate old page belongs to + * @old_page: Old page to dissolve + * @list: List to isolate the page in case we need to + * Returns 0 on success, otherwise negated error. + */ +static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, + struct list_head *list) +{ + int nid = page_to_nid(old_page); + struct page *new_page; + int ret = 0; + + new_page = alloc_replacement_page(h, nid); + if (IS_ERR(new_page)) + return PTR_ERR(new_page); + retry: spin_lock_irq(&hugetlb_lock); if (!PageHuge(old_page)) { @@ -2783,21 +2815,7 @@ static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page, cond_resched(); goto retry; } else { - /* - * Ok, old_page is still a genuine free hugepage. Remove it from - * the freelist and decrease the counters. These will be - * incremented again when calling __prep_account_new_huge_page() - * and enqueue_huge_page() for new_page. The counters will remain - * stable since this happens under the lock. - */ - remove_hugetlb_page(h, old_page, false); - - /* - * Ref count on new page is already zero as it was dropped - * earlier. It can be directly added to the pool free list. - */ - __prep_account_new_huge_page(h, nid); - enqueue_huge_page(h, new_page); + replace_hugepage(h, nid, old_page, new_page); /* * Pages have been replaced, we can safely free the old one.