From nobody Mon Feb 9 12:27:55 2026 Received: from wout3-smtp.messagingengine.com (wout3-smtp.messagingengine.com [64.147.123.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A54D1292FD for ; Tue, 20 Feb 2024 18:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=64.147.123.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708453966; cv=none; b=lCq4m7TrcSOIpPbmJv2tvSw8PDb3hyV4QpHMjDBQmt0Hs5YxM9tsxDCeBjRm+IJfQffna4Gq0p06THPrj+FSa0FbSfyah4MnyoRhjpMDmYJh0XX39A0jUfWAMPWrH2Omu4ZOMbMJ5klnBVCg3aTVC1maWTAXgeuTjWRpwJqpHlc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708453966; c=relaxed/simple; bh=HhOvTaFPif92cm6vV+oSKDGsnXOY2r1rAN3bwiOwq/I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rpRIW/wVumZT9te2cIEFKLsAQZb50qfklcaAIv/mVXy8LcPvUhrGJHRkQWWkXykEbUadY8DnOw9YnT/M9HLGIjKadNfDW+C4rmFjSmcdN+O7Qd+kk0Uqy7g5ijV5OaOREJ6AcXmPgx7j+p76APGTfjsO5PJkTkGJvuNj38Ezu7E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sent.com; spf=pass smtp.mailfrom=sent.com; dkim=pass (2048-bit key) header.d=sent.com header.i=@sent.com header.b=IBCxnz5k; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=jiSueTP2; arc=none smtp.client-ip=64.147.123.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sent.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sent.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sent.com header.i=@sent.com header.b="IBCxnz5k"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="jiSueTP2" Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 8B5B03200A4D; Tue, 20 Feb 2024 13:32:42 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute2.internal (MEProxy); Tue, 20 Feb 2024 13:32:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sent.com; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:reply-to:subject:subject:to:to; s=fm1; t= 1708453962; x=1708540362; bh=VthfB9xHWXamr5LNX5aI7SP9sOuq2T7O1Uc OskPjsOI=; b=IBCxnz5kEzrcnVVh8byadrCYLGeY+gCPJu4KYwlIh6EYBa+DLmh DVgGL5okBSyRGQJM8oS2cHgWVRx3A/VIJsXjlm3/Q8xVAl81p8ZTP/MDsKI2ilKg j1Ao/xGia5AXXNoAg2GqbL8XA2QOpbmWkUYhgoERs1srQZHv3C2sJWikcSOgJwz/ +rJtvtpe0YpSvNLJwH2TfKlclX3dzkRoKZiE4kGoAG4IF8+gMNdMFu8x2Hi8ckn9 gW/FXHoVwtF++TWclK+cV7TKWHLboYQV2MVqYg/G0zDsRVdgwpivGy01VjhcrLvX Bh05vMbRhOlvB5aLeaXKrxXzQ4cKhU/uynQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:reply-to:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t= 1708453962; x=1708540362; bh=VthfB9xHWXamr5LNX5aI7SP9sOuq2T7O1Uc OskPjsOI=; b=jiSueTP2NFAW16xmDieh0jQv1EMcSklBlVsdVriYGBp7o94Ggcq fl0/Y10zf0QltMFk5nK18Kf7eVAmp5HMBYWlwcMMrbzm2fCsUiP4W6EWAgsjePP1 pugKuaGP0Dg72DLTzagqAwEVofFHzqE8dUqb7Ia413zAYAzGmQ/RmNmNMqu80iK8 dpyfuQmLBOu24LqQBr77Xce4SnEjXhA2bFEF/1r0RToVXdwMDXckGJibLq+U8kYX /vNtbBD9Is8Z+R/sn+DyixhqNPCqW9vOfAJ/u/DEMTKXT0EFLnPVqCUjBp/RfVJ4 2jWosqtyzTbBoRRq+5SVmMelvVS5BbOYhzg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvledrfedtgdduudehucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhhrgggtgfesthekredtredtjeenucfhrhhomhepkghi ucgjrghnuceoiihirdihrghnsehsvghnthdrtghomheqnecuggftrfgrthhtvghrnhepje ekteekffelleekudfftdefvddtjeejuedtuedtteegjefgvedtfedujeekieevnecuvehl uhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepiihirdihrghnse hsvghnthdrtghomh X-ME-Proxy: Feedback-ID: iccd040f4:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 20 Feb 2024 13:32:41 -0500 (EST) From: Zi Yan To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Zi Yan , "Huang, Ying" , Ryan Roberts , Andrew Morton , "Matthew Wilcox (Oracle)" , David Hildenbrand , "Yin, Fengwei" , Yu Zhao , Vlastimil Babka , "Kirill A . Shutemov" , Johannes Weiner , Baolin Wang , Kemeng Shi , Mel Gorman , Rohan Puri , Mcgrof Chamberlain , Adam Manzanares , "Vishal Moola (Oracle)" Subject: [PATCH v7 2/4] mm/compaction: enable compacting >0 order folios. Date: Tue, 20 Feb 2024 13:32:18 -0500 Message-ID: <20240220183220.1451315-3-zi.yan@sent.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240220183220.1451315-1-zi.yan@sent.com> References: <20240220183220.1451315-1-zi.yan@sent.com> Reply-To: Zi Yan Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable From: Zi Yan migrate_pages() supports >0 order folio migration and during compaction, even if compaction_alloc() cannot provide >0 order free pages, migrate_pages() can split the source page and try to migrate the base pages from the split. It can be a baseline and start point for adding support for compacting >0 order folios. Signed-off-by: Zi Yan Suggested-by: Huang Ying Reviewed-by: Baolin Wang Reviewed-by: Vlastimil Babka Tested-by: Baolin Wang Tested-by: Yu Zhao Cc: Adam Manzanares Cc: David Hildenbrand Cc: Johannes Weiner Cc: Kemeng Shi Cc: Kirill A. Shutemov Cc: Luis Chamberlain Cc: Matthew Wilcox (Oracle) Cc: Mel Gorman Cc: Ryan Roberts Cc: Vishal Moola (Oracle) Cc: Vlastimil Babka Cc: Yin Fengwei --- mm/compaction.c | 101 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 76 insertions(+), 25 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index ccd447282665..6509fab27be9 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -40,9 +40,22 @@ static inline void count_compact_events(enum vm_event_it= em item, long delta) { count_vm_events(item, delta); } + +/* + * order =3D=3D -1 is expected when compacting proactively via + * 1. /proc/sys/vm/compact_memory + * 2. /sys/devices/system/node/nodex/compact + * 3. /proc/sys/vm/compaction_proactiveness + */ +static inline bool is_via_compact_memory(int order) +{ + return order =3D=3D -1; +} + #else #define count_compact_event(item) do { } while (0) #define count_compact_events(item, delta) do { } while (0) +static inline bool is_via_compact_memory(int order) { return false; } #endif =20 #if defined CONFIG_COMPACTION || defined CONFIG_CMA @@ -816,6 +829,32 @@ static bool too_many_isolated(struct compact_control *= cc) return too_many; } =20 +/** + * skip_isolation_on_order() - determine when to skip folio isolation base= d on + * folio order and compaction target order + * @order: to-be-isolated folio order + * @target_order: compaction target order + * + * This avoids unnecessary folio isolations during compaction. + */ +static bool skip_isolation_on_order(int order, int target_order) +{ + /* + * Unless we are performing global compaction (i.e., + * is_via_compact_memory), skip any folios that are larger than the + * target order: we wouldn't be here if we'd have a free folio with + * the desired target_order, so migrating this folio would likely fail + * later. + */ + if (!is_via_compact_memory(target_order) && order >=3D target_order) + return true; + /* + * We limit memory compaction to pageblocks and won't try + * creating free blocks of memory that are larger than that. + */ + return order >=3D pageblock_order; +} + /** * isolate_migratepages_block() - isolate all migrate-able pages within * a single pageblock @@ -947,7 +986,22 @@ isolate_migratepages_block(struct compact_control *cc,= unsigned long low_pfn, valid_page =3D page; } =20 - if (PageHuge(page) && cc->alloc_contig) { + if (PageHuge(page)) { + /* + * skip hugetlbfs if we are not compacting for pages + * bigger than its order. THPs and other compound pages + * are handled below. + */ + if (!cc->alloc_contig) { + const unsigned int order =3D compound_order(page); + + if (order <=3D MAX_PAGE_ORDER) { + low_pfn +=3D (1UL << order) - 1; + nr_scanned +=3D (1UL << order) - 1; + } + goto isolate_fail; + } + /* for alloc_contig case */ if (locked) { unlock_page_lruvec_irqrestore(locked, flags); locked =3D NULL; @@ -1008,21 +1062,24 @@ isolate_migratepages_block(struct compact_control *= cc, unsigned long low_pfn, } =20 /* - * Regardless of being on LRU, compound pages such as THP and - * hugetlbfs are not to be compacted unless we are attempting - * an allocation much larger than the huge page size (eg CMA). - * We can potentially save a lot of iterations if we skip them - * at once. The check is racy, but we can consider only valid - * values and the only danger is skipping too much. + * Regardless of being on LRU, compound pages such as THP + * (hugetlbfs is handled above) are not to be compacted unless + * we are attempting an allocation larger than the compound + * page size. We can potentially save a lot of iterations if we + * skip them at once. The check is racy, but we can consider + * only valid values and the only danger is skipping too much. */ if (PageCompound(page) && !cc->alloc_contig) { const unsigned int order =3D compound_order(page); =20 - if (likely(order <=3D MAX_PAGE_ORDER)) { - low_pfn +=3D (1UL << order) - 1; - nr_scanned +=3D (1UL << order) - 1; + /* Skip based on page order and compaction target order. */ + if (skip_isolation_on_order(order, cc->order)) { + if (order <=3D MAX_PAGE_ORDER) { + low_pfn +=3D (1UL << order) - 1; + nr_scanned +=3D (1UL << order) - 1; + } + goto isolate_fail; } - goto isolate_fail; } =20 /* @@ -1165,10 +1222,11 @@ isolate_migratepages_block(struct compact_control *= cc, unsigned long low_pfn, } =20 /* - * folio become large since the non-locked check, - * and it's on LRU. + * Check LRU folio order under the lock */ - if (unlikely(folio_test_large(folio) && !cc->alloc_contig)) { + if (unlikely(skip_isolation_on_order(folio_order(folio), + cc->order) && + !cc->alloc_contig)) { low_pfn +=3D folio_nr_pages(folio) - 1; nr_scanned +=3D folio_nr_pages(folio) - 1; folio_set_lru(folio); @@ -1788,6 +1846,10 @@ static struct folio *compaction_alloc(struct folio *= src, unsigned long data) struct compact_control *cc =3D (struct compact_control *)data; struct folio *dst; =20 + /* this makes migrate_pages() split the source page and retry */ + if (folio_test_large(src)) + return NULL; + if (list_empty(&cc->freepages)) { isolate_freepages(cc); =20 @@ -2090,17 +2152,6 @@ static isolate_migrate_t isolate_migratepages(struct= compact_control *cc) return cc->nr_migratepages ? ISOLATE_SUCCESS : ISOLATE_NONE; } =20 -/* - * order =3D=3D -1 is expected when compacting proactively via - * 1. /proc/sys/vm/compact_memory - * 2. /sys/devices/system/node/nodex/compact - * 3. /proc/sys/vm/compaction_proactiveness - */ -static inline bool is_via_compact_memory(int order) -{ - return order =3D=3D -1; -} - /* * Determine whether kswapd is (or recently was!) running on this node. * --=20 2.43.0