From patchwork Wed Mar 10 15:08:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar Salvador X-Patchwork-Id: 12128197 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBD88C433E0 for ; Wed, 10 Mar 2021 15:09:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6CB6564F4B for ; Wed, 10 Mar 2021 15:09:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CB6564F4B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C8B18D01BA; Wed, 10 Mar 2021 10:09:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 079018D01A6; Wed, 10 Mar 2021 10:09:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E5D678D01BA; Wed, 10 Mar 2021 10:09:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C76CF8D01A6 for ; Wed, 10 Mar 2021 10:09:22 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 85E311803951A for ; Wed, 10 Mar 2021 15:09:22 +0000 (UTC) X-FDA: 77904298164.16.E6A69A5 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf12.hostedemail.com (Postfix) with ESMTP id 9E26F3FA for ; Wed, 10 Mar 2021 15:09:09 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A7E46AD72; Wed, 10 Mar 2021 15:09:01 +0000 (UTC) From: Oscar Salvador To: Andrew Morton Cc: Vlastimil Babka , David Hildenbrand , Michal Hocko , Muchun Song , Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: [PATCH v4 2/4] mm,compaction: Let isolate_migratepages_{range,block} return error codes Date: Wed, 10 Mar 2021 16:08:51 +0100 Message-Id: <20210310150853.13541-3-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20210310150853.13541-1-osalvador@suse.de> References: <20210310150853.13541-1-osalvador@suse.de> X-Stat-Signature: cwoefm97cfpzh3wrted11udskj71a5wm X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 9E26F3FA Received-SPF: none (suse.de>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: none/none X-HE-Tag: 1615388949-91144 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: Currently, isolate_migratepages_{range,block} and their callers use a pfn == 0 vs pfn != 0 scheme to let the caller know whether there was any error during isolation. This does not work as soon as we need to start reporting different error codes and make sure we pass them down the chain, so they are properly interpreted by functions like e.g: alloc_contig_range. Let us rework isolate_migratepages_{range,block} so we can report error codes. Since isolate_migratepages_block will stop returning the next pfn to be scanned, we reuse the cc->migrate_pfn field to keep track of that. Signed-off-by: Oscar Salvador --- mm/compaction.c | 48 ++++++++++++++++++++++++------------------------ mm/internal.h | 2 +- mm/page_alloc.c | 7 +++---- 3 files changed, 28 insertions(+), 29 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index e04f4476e68e..5769753a8f60 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -787,15 +787,16 @@ static bool too_many_isolated(pg_data_t *pgdat) * * Isolate all pages that can be migrated from the range specified by * [low_pfn, end_pfn). The range is expected to be within same pageblock. - * Returns zero if there is a fatal signal pending, otherwise PFN of the - * first page that was not scanned (which may be both less, equal to or more - * than end_pfn). + * Returns -EINTR in case we need to abort when we have too many isolated pages + * due to e.g: signal pending, async mode or having still pages to migrate, or 0. + * cc->migrate_pfn will contain the next pfn to scan (which may be both less, + * equal to or more that end_pfn). * * The pages are isolated on cc->migratepages list (not required to be empty), * and cc->nr_migratepages is updated accordingly. The cc->migrate_pfn field * is neither read nor updated. */ -static unsigned long +static int isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, unsigned long end_pfn, isolate_mode_t isolate_mode) { @@ -810,6 +811,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, unsigned long next_skip_pfn = 0; bool skip_updated = false; + cc->migrate_pfn = low_pfn; + /* * Ensure that there are not too many pages isolated from the LRU * list by either parallel reclaimers or compaction. If there are, @@ -818,16 +821,16 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, while (unlikely(too_many_isolated(pgdat))) { /* stop isolation if there are still pages not migrated */ if (cc->nr_migratepages) - return 0; + return -EINTR; /* async migration should just abort */ if (cc->mode == MIGRATE_ASYNC) - return 0; + return -EINTR; congestion_wait(BLK_RW_ASYNC, HZ/10); if (fatal_signal_pending(current)) - return 0; + return -EINTR; } cond_resched(); @@ -1130,7 +1133,9 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, if (nr_isolated) count_compact_events(COMPACTISOLATED, nr_isolated); - return low_pfn; + cc->migrate_pfn = low_pfn; + + return 0; } /** @@ -1139,15 +1144,15 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn, * @start_pfn: The first PFN to start isolating. * @end_pfn: The one-past-last PFN. * - * Returns zero if isolation fails fatally due to e.g. pending signal. - * Otherwise, function returns one-past-the-last PFN of isolated page - * (which may be greater than end_pfn if end fell in a middle of a THP page). + * Returns -EINTR in case isolation fails fatally due to e.g. pending signal, + * or 0. */ -unsigned long +int isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn, block_start_pfn, block_end_pfn; + int ret = 0; /* Scan block by block. First and last block may be incomplete */ pfn = start_pfn; @@ -1166,17 +1171,17 @@ isolate_migratepages_range(struct compact_control *cc, unsigned long start_pfn, block_end_pfn, cc->zone)) continue; - pfn = isolate_migratepages_block(cc, pfn, block_end_pfn, - ISOLATE_UNEVICTABLE); + ret = isolate_migratepages_block(cc, pfn, block_end_pfn, + ISOLATE_UNEVICTABLE); - if (!pfn) + if (ret) break; if (cc->nr_migratepages >= COMPACT_CLUSTER_MAX) break; } - return pfn; + return ret; } #endif /* CONFIG_COMPACTION || CONFIG_CMA */ @@ -1847,7 +1852,7 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) */ for (; block_end_pfn <= cc->free_pfn; fast_find_block = false, - low_pfn = block_end_pfn, + cc->migrate_pfn = low_pfn = block_end_pfn, block_start_pfn = block_end_pfn, block_end_pfn += pageblock_nr_pages) { @@ -1889,10 +1894,8 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) } /* Perform the isolation */ - low_pfn = isolate_migratepages_block(cc, low_pfn, - block_end_pfn, isolate_mode); - - if (!low_pfn) + if (isolate_migratepages_block(cc, low_pfn, block_end_pfn, + isolate_mode)) return ISOLATE_ABORT; /* @@ -1903,9 +1906,6 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) break; } - /* Record where migration scanner will be restarted. */ - cc->migrate_pfn = low_pfn; - return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE; } diff --git a/mm/internal.h b/mm/internal.h index 9902648f2206..e670abb1154c 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -261,7 +261,7 @@ struct capture_control { unsigned long isolate_freepages_range(struct compact_control *cc, unsigned long start_pfn, unsigned long end_pfn); -unsigned long +int isolate_migratepages_range(struct compact_control *cc, unsigned long low_pfn, unsigned long end_pfn); int find_suitable_fallback(struct free_area *area, unsigned int order, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 94467f1b85ff..2184e3ef4116 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8477,11 +8477,10 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, if (list_empty(&cc->migratepages)) { cc->nr_migratepages = 0; - pfn = isolate_migratepages_range(cc, pfn, end); - if (!pfn) { - ret = -EINTR; + ret = isolate_migratepages_range(cc, pfn, end); + if (ret) break; - } + pfn = cc->migrate_pfn; tries = 0; } else if (++tries == 5) { ret = -EBUSY;