From patchwork Tue Dec 7 03:07:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 12660989 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 6EC49C433EF for ; Tue, 7 Dec 2021 03:09:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 922196B0089; Mon, 6 Dec 2021 22:08:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 903416B008A; Mon, 6 Dec 2021 22:08:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E94D6B008C; Mon, 6 Dec 2021 22:08:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0046.hostedemail.com [216.40.44.46]) by kanga.kvack.org (Postfix) with ESMTP id 723BC6B0089 for ; Mon, 6 Dec 2021 22:08:37 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 316611809554A for ; Tue, 7 Dec 2021 03:08:27 +0000 (UTC) X-FDA: 78889515054.28.9531056 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf05.hostedemail.com (Postfix) with ESMTP id CC52E100002 for ; Tue, 7 Dec 2021 03:08:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638846506; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=eS5hnHo6fS3srX/T0Jg5HoFYDVnRWpFswXlegYGnrds=; b=TIkvDbqXZG7jhmE4ExcpN7PSmWAzbTHZN/qF4SctRt0TCAaz1fnq5gXHHiXlH6zQuofomj BUrY7SOjNP8xFEl2yO+tlUVYd1MnceI0hrEHyoJR+HfcnXeXfbBUs3fZVFwrMJ/dZWkINH aiKppXKH8F9SOKMtIUVakLlXYqPGh4Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-309-KJEMnVkSM96TyaxgypcYXA-1; Mon, 06 Dec 2021 22:08:23 -0500 X-MC-Unique: KJEMnVkSM96TyaxgypcYXA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 345E781CCB4; Tue, 7 Dec 2021 03:08:21 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-87.pek2.redhat.com [10.72.12.87]) by smtp.corp.redhat.com (Postfix) with ESMTP id DD48719C59; Tue, 7 Dec 2021 03:08:15 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, hch@lst.de, robin.murphy@arm.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, vbabka@suse.cz, m.szyprowski@samsung.com, John.p.donnelly@oracle.com, kexec@lists.infradead.org, Baoquan He Subject: [PATCH RESEND v2 3/5] mm_zone: add function to check if managed dma zone exists Date: Tue, 7 Dec 2021 11:07:48 +0800 Message-Id: <20211207030750.30824-4-bhe@redhat.com> In-Reply-To: <20211207030750.30824-1-bhe@redhat.com> References: <20211207030750.30824-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: CC52E100002 X-Stat-Signature: 1oaafnzatqtxqwpm33e8fyebq4retsbu Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=TIkvDbqX; spf=none (imf05.hostedemail.com: domain of bhe@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=bhe@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-HE-Tag: 1638846506-274191 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: In some places of the current kernel, it assumes that dma zone must have managed pages if CONFIG_ZONE_DMA is enabled. While this is not always true. E.g in kdump kernel of x86_64, only low 1M is presented and locked down at very early stage of boot, so that there's no managed pages at all in DMA zone. This exception will always cause page allocation failure if page is requested from DMA zone. Here add function has_managed_dma() and the relevant helper functions to check if there's DMA zone with managed pages. It will be used in later patches. Signed-off-by: Baoquan He --- include/linux/mmzone.h | 21 +++++++++++++++++++++ mm/page_alloc.c | 11 +++++++++++ 2 files changed, 32 insertions(+) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 58e744b78c2c..82d23e13e0e5 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -998,6 +998,18 @@ static inline bool zone_is_zone_device(struct zone *zone) } #endif +#ifdef CONFIG_ZONE_DMA +static inline bool zone_is_dma(struct zone *zone) +{ + return zone_idx(zone) == ZONE_DMA; +} +#else +static inline bool zone_is_dma(struct zone *zone) +{ + return false; +} +#endif + /* * Returns true if a zone has pages managed by the buddy allocator. * All the reclaim decisions have to use this function rather than @@ -1046,6 +1058,7 @@ static inline int is_highmem_idx(enum zone_type idx) #endif } +bool has_managed_dma(void); /** * is_highmem - helper function to quickly check if a struct zone is a * highmem zone or not. This is an attempt to keep references @@ -1131,6 +1144,14 @@ extern struct zone *next_zone(struct zone *zone); ; /* do nothing */ \ else +#define for_each_managed_zone(zone) \ + for (zone = (first_online_pgdat())->node_zones; \ + zone; \ + zone = next_zone(zone)) \ + if (!managed_zone(zone)) \ + ; /* do nothing */ \ + else + static inline struct zone *zonelist_zone(struct zoneref *zoneref) { return zoneref->zone; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c5952749ad40..ac0ea42a4e5f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -9459,4 +9459,15 @@ bool take_page_off_buddy(struct page *page) spin_unlock_irqrestore(&zone->lock, flags); return ret; } + +bool has_managed_dma(void) +{ + struct zone *zone; + + for_each_managed_zone(zone) { + if (zone_is_dma(zone)) + return true; + } + return false; +} #endif