From patchwork Fri Nov 24 11:05:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charan Teja Kalla X-Patchwork-Id: 169393 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:ce62:0:b0:403:3b70:6f57 with SMTP id o2csp1084811vqx; Fri, 24 Nov 2023 03:07:07 -0800 (PST) X-Google-Smtp-Source: AGHT+IHngJYN3J36Ge2rnMe2nsryjS4Cgf97lPjMThy5Aop/CPtrXBuEK96vYjbg5gkImLSpoNVO X-Received: by 2002:a05:6a20:2d1e:b0:18b:960a:efc2 with SMTP id g30-20020a056a202d1e00b0018b960aefc2mr2604100pzl.10.1700824026836; Fri, 24 Nov 2023 03:07:06 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1700824026; cv=none; d=google.com; s=arc-20160816; b=jfkUyG64UxRyS6KWAmQf3kWqA+krYuscoDFpQ9t3zI1obPzGkYm4Y6nV9w06y6r9kc HmTlV7lG/SbThrGrYWP4OxUHNjNcRqbH0LeWBOf9inxVKkIH/lf4+4p6V0YuGlUqlL7K PSmT6kACB53Kxx+3VPw7GzvPq++dYwiLtSlMG1oa6oTY4jab12HqKJW103ePzlNIUi2U AOmUN8eXxkEELnKUuPx/LfUXuW71TUvqj1yF82y9vvow1d9jrGAJyufBnpCMu1P/2Qei +0fPEnhHml99wcLiOjEkbQfl8Sg++qDuXVWNSGkyMQxT3Jy+8lCCl6G0bV6eGhDzn56b nFTg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:in-reply-to:message-id :date:subject:cc:to:from:dkim-signature; bh=XevrrF9/BcNyXtfgPOZjSxlAUBouemoME5zNztn1Vg8=; fh=OEZ1X2ugt64Sg3RaiLhA7IjZ0579kVxN/CI/M7AE/gY=; b=JOQGAh9Dgt5uWcjd4H1x7g6PAOgfRXNdVQVp0gxPY1mAB6srEIMIANcewvq2YlnXBh Wcv7ZUR4Xknrmoq9RX0ANVoY1SWYsFjafQvtKbzGlGxjuCCzGiISRRY7jQ9LJnooOHu/ 7Y2BOSdelhaB94FAvSiHGFP9Q7Lf4qY9h7kQnw4BiyZlymqCh3JE7/+Dg1Q6S+pbRKD7 Hl0gesmCqwUHxL92oNcNgVs3rDl44fV5NsnjVHGkCgU9QLO4tR942Owi57uOYgV5l9mt NpacbOhpFO90b8YlaKKYywAhbNMmZ4lItvl/CRffV4tnNHvL5LxKhrNEs1kskAkjPd3N aLog== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@quicinc.com header.s=qcppdkim1 header.b=Ox4aOybw; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=quicinc.com Received: from howler.vger.email (howler.vger.email. [2620:137:e000::3:4]) by mx.google.com with ESMTPS id y16-20020aa79430000000b0068a590d803csi3128640pfo.361.2023.11.24.03.07.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Nov 2023 03:07:06 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4; Authentication-Results: mx.google.com; dkim=pass header.i=@quicinc.com header.s=qcppdkim1 header.b=Ox4aOybw; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=quicinc.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by howler.vger.email (Postfix) with ESMTP id 86E34804917B; Fri, 24 Nov 2023 03:07:03 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at howler.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345743AbjKXLGh (ORCPT + 99 others); Fri, 24 Nov 2023 06:06:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345742AbjKXLGe (ORCPT ); Fri, 24 Nov 2023 06:06:34 -0500 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB1A3D71 for ; Fri, 24 Nov 2023 03:06:40 -0800 (PST) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3AO66F0G031216; Fri, 24 Nov 2023 11:06:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=XevrrF9/BcNyXtfgPOZjSxlAUBouemoME5zNztn1Vg8=; b=Ox4aOybwvkKC9GaMCV5HxQUruXA0yH6ef3yTi+Aul6L6RXTbWCdwnkRypAI8345YZycw yJvH3cLs/qnracKLrtjT/T/D4InOgWFrJMWYVgvlKNuOfBteTP97NMiJ7Kral8hU1LP1 GL1CckUcqJqRxW2uVg370rQxlbSy5U9JdiIJjE9TJGVP7gfm44AzAyTrUNLvLB42Oex/ x2i1D1ZfVRQ6qXci0dPDdio2iIGn6t4qCBJ1ov2e8+rSjvqPtzemEELdqOQKt+27ZfEe 28m12XHFxGouOry5v9vkWt6yW2/Li7IyV3qKBXkQ4zBCz2/jYxMGibTvNZ+eCobSYFbw tQ== Received: from nalasppmta01.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ujp8x0ub6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Nov 2023 11:06:23 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3AOB6NYA001785 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Nov 2023 11:06:23 GMT Received: from hu-charante-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Fri, 24 Nov 2023 03:06:19 -0800 From: Charan Teja Kalla To: , , , , , , CC: , , Charan Teja Kalla Subject: [PATCH V3 1/2] mm: page_alloc: correct high atomic reserve calculations Date: Fri, 24 Nov 2023 16:35:52 +0530 Message-ID: <1660034138397b82a0a8b6ae51cbe96bd583d89e.1700821416.git.quic_charante@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: vvC70aAGvT9o9sBR5JZxO4PBCB_o6bew X-Proofpoint-ORIG-GUID: vvC70aAGvT9o9sBR5JZxO4PBCB_o6bew X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-23_15,2023-11-22_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 adultscore=0 mlxlogscore=638 clxscore=1015 spamscore=0 lowpriorityscore=0 impostorscore=0 malwarescore=0 bulkscore=0 mlxscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311240086 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on howler.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Fri, 24 Nov 2023 03:07:03 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1783443254700591214 X-GMAIL-MSGID: 1783443254700591214 reserve_highatomic_pageblock() aims to reserve the 1% of the managed pages of a zone, which is used for the high order atomic allocations. It uses the below calculation to reserve: static void reserve_highatomic_pageblock(struct page *page, ....) { ....... max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages; if (zone->nr_reserved_highatomic >= max_managed) goto out; zone->nr_reserved_highatomic += pageblock_nr_pages; set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); out: .... } Since we are always appending the 1% of zone managed pages count to pageblock_nr_pages, the minimum it is turning into 2 pageblocks as the nr_reserved_highatomic is incremented/decremented in pageblock sizes. Encountered a system(actually a VM running on the Linux kernel) with the below zone configuration: Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB reserved_highatomic:8192KB managed:49224kB The existing calculations making it to reserve the 8MB(with pageblock size of 4MB) i.e. 16% of the zone managed memory. Reserving such high amount of memory can easily exert memory pressure in the system thus may lead into unnecessary reclaims till unreserving of high atomic reserves. Since high atomic reserves are managed in pageblock size granules, as MIGRATE_HIGHATOMIC is set for such pageblock, fix the calculations for high atomic reserves as, minimum is pageblock size , maximum is approximately 1% of the zone managed pages. Acked-by: Mel Gorman Signed-off-by: Charan Teja Kalla Acked-by: David Rientjes --- mm/page_alloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 733732e..a789dfd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1884,10 +1884,11 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone) unsigned long max_managed, flags; /* - * Limit the number reserved to 1 pageblock or roughly 1% of a zone. + * The number reserved as: minimum is 1 pageblock, maximum is + * roughly 1% of a zone. * Check is race-prone but harmless. */ - max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages; + max_managed = ALIGN((zone_managed_pages(zone) / 100), pageblock_nr_pages); if (zone->nr_reserved_highatomic >= max_managed) return;