From nobody Mon Feb 9 12:24:05 2026 Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) (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 17A9F1474B2 for ; Fri, 2 Feb 2024 16:16:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.111.4.26 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706890581; cv=none; b=ADFiwMIzklFKesO8G1WdnIGqcYK0fC3BCcguf9R56l7yo3AOegsUNfkDPp50gyiSHa3h6U6/b8yuuyOAHhTFNmUiDjz31BN9LBdhjELEHfUPRckkKM+0rYWph+WRk1AWqXNbL18mM5fv2DYS/y/yM0YfShFMNmQ16mrkHVnBCLs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706890581; c=relaxed/simple; bh=JQ3XAd6+1pk8HTCEGu8mix5SOQ7LMO81KCcmw2HK8Iw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rDfCbmNNWS0hrEybw09hTXwexXHsQtg13kA8cvJ933cG/LvYZQBu5vTUUG0ZKf6K0/U8WNwXvQxD2E3B7KUA9V+jIYSTLZen9Um3qwPs1KKLwQQ06aDXdZCsEiyxnPWXfwkyX4AAH5pxmh8JGLUTCXBgS8npWdUcDLkIJjRAYvI= 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=Q6BNiPci; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=w3EzSPMY; arc=none smtp.client-ip=66.111.4.26 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="Q6BNiPci"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="w3EzSPMY" Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id 450FD5C0108; Fri, 2 Feb 2024 11:16:19 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Fri, 02 Feb 2024 11:16:19 -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=fm3; t= 1706890579; x=1706976979; bh=Srz2TBF5bSmmDzT+fRItHrkdBt/FNKVEiEo yh1M6V+0=; b=Q6BNiPcizadAd+EZgLpzobSWkpvEDzg+ntUAZW2HFba3/Lbpme2 O8sD/KsTLcClEooEDS+rgni1VKTOJVvjKG2BECTjNiNda9PMom5VpxTwxk+kmX9g 5SJAxrVHTNtZxoS5jAUi56r/D8XWcS0OJh2+HEwhuwHmt1t9F6ixsOpYuh0Z62lf jsolvlGzfHgQFVTRoeCZd2VaMnTaM1ocYqJaIOR1z9/NUXsfDnUeuUp37YoN3RGo h9R7gudHRW7KTw4tSyeCZ1fkU5pRSQ2k5vAl5Zfe3Gl+tFLgCwcmgP1//oQ2W0+0 ZAsBefLjP95IPfEJx9zsNtGrcaHxRnXII7w== 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=fm3; t= 1706890579; x=1706976979; bh=Srz2TBF5bSmmDzT+fRItHrkdBt/FNKVEiEo yh1M6V+0=; b=w3EzSPMYiSxw7VrU6CcZVS7tnyWg0o5f4EO+FRuCOUgJup6WH3A gUN6QtlNYcx+Xn13uj0UTgRkf7/WGHrUMYbh0SZWawyQ1VsQMjqfWMGZIYZFIdqB TgfodME8fk/7pVIskKCsZPmLBTaZTRcAhff4gV09XWLcq2pcbc6xc//W7iVxO8y1 k6Mv24maaJmmjZhsBbAUxbjFqyQp+8mkxO3FQkx6tvJUlZgqg+MLuMvmItlouDmy QqdBcxCFwfun+0ZBRcIHVEJ2iA/lBy8U/xlgdDOcFYEGbzGP8Vtg7NECbWUCEn7U NABFdFaLw/It9y8LVlvkv8GiKqoNy+b8vYQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvkedrfedugedgkeehucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhhrgggtgfesthekredtredtjeenucfhrhhomhepkghi ucgjrghnuceoiihirdihrghnsehsvghnthdrtghomheqnecuggftrfgrthhtvghrnhepje ekteekffelleekudfftdefvddtjeejuedtuedtteegjefgvedtfedujeekieevnecuvehl uhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepiihirdihrghnse hsvghnthdrtghomh X-ME-Proxy: Feedback-ID: iccd040f4:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 2 Feb 2024 11:16:17 -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 v3 3/3] mm/compaction: optimize >0 order folio compaction with free page split. Date: Fri, 2 Feb 2024 11:15:54 -0500 Message-ID: <20240202161554.565023-4-zi.yan@sent.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202161554.565023-1-zi.yan@sent.com> References: <20240202161554.565023-1-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 During migration in a memory compaction, free pages are placed in an array of page lists based on their order. But the desired free page order (i.e., the order of a source page) might not be always present, thus leading to migration failures and premature compaction termination. Split a high order free pages when source migration page has a lower order to increase migration successful rate. Note: merging free pages when a migration fails and a lower order free page is returned via compaction_free() is possible, but there is too much work. Since the free pages are not buddy pages, it is hard to identify these free pages using existing PFN-based page merging algorithm. Signed-off-by: Zi Yan --- mm/compaction.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index 58a4e3fb72ec..fa9993c8a389 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1832,9 +1832,43 @@ static struct folio *compaction_alloc(struct folio *= src, unsigned long data) struct compact_control *cc =3D (struct compact_control *)data; struct folio *dst; int order =3D folio_order(src); + bool has_isolated_pages =3D false; =20 +again: if (!cc->freepages[order].nr_pages) { - isolate_freepages(cc); + int i; + + for (i =3D order + 1; i < NR_PAGE_ORDERS; i++) { + if (cc->freepages[i].nr_pages) { + struct page *freepage =3D + list_first_entry(&cc->freepages[i].pages, + struct page, lru); + + int start_order =3D i; + unsigned long size =3D 1 << start_order; + + list_del(&freepage->lru); + cc->freepages[i].nr_pages--; + + while (start_order > order) { + start_order--; + size >>=3D 1; + + list_add(&freepage[size].lru, + &cc->freepages[start_order].pages); + cc->freepages[start_order].nr_pages++; + set_page_private(&freepage[size], start_order); + } + dst =3D (struct folio *)freepage; + goto done; + } + } + if (!has_isolated_pages) { + isolate_freepages(cc); + has_isolated_pages =3D true; + goto again; + } + if (!cc->freepages[order].nr_pages) return NULL; } @@ -1842,6 +1876,7 @@ static struct folio *compaction_alloc(struct folio *s= rc, unsigned long data) dst =3D list_first_entry(&cc->freepages[order].pages, struct folio, lru); cc->freepages[order].nr_pages--; list_del(&dst->lru); +done: post_alloc_hook(&dst->page, order, __GFP_MOVABLE); if (order) prep_compound_page(&dst->page, order); --=20 2.43.0