From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 9B2C0C433E0 for ; Fri, 12 Feb 2021 17:34:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 645E264DA5 for ; Fri, 12 Feb 2021 17:34:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231479AbhBLRe1 (ORCPT ); Fri, 12 Feb 2021 12:34:27 -0500 Received: from mail29.static.mailgun.info ([104.130.122.29]:27321 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231258AbhBLReV (ORCPT ); Fri, 12 Feb 2021 12:34:21 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1613151237; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=K2S35ZMNfNKZ70ztSuai8wLbHzfvfWAbdZyFwSz4e3Q=; b=oqQ3IdJ+ISFP42MHUsWAqOFSZ4HSvxtquZ0gbk8gxVrfMuBv/aYJkX5gSA1Cj41T0jq+clq/ AiMpmIgKsrkRYsUM2fH5hgVJEiYfZVhG/whefI2m5O+4DJ82eEopj2XGB+YuJoFzcU07AD4f JFm5bijeuLY6Ib+9lk5LM0lmgEE= X-Mailgun-Sending-Ip: 104.130.122.29 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-east-1.postgun.com with SMTP id 6026bbea81f6c45dceb468c5 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 12 Feb 2021 17:33:30 GMT Sender: charante=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 98748C433ED; Fri, 12 Feb 2021 17:33:29 +0000 (UTC) Received: from charante-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: charante) by smtp.codeaurora.org (Postfix) with ESMTPSA id 82B37C433CA; Fri, 12 Feb 2021 17:33:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 82B37C433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=charante@codeaurora.org From: Charan Teja Reddy To: akpm@linux-foundation.org, rientjes@google.com, vbabka@suse.cz, linux-mm@kvack.org Cc: vinmenon@codeaurora.org, linux-kernel@vger.kernel.org, Charan Teja Reddy Subject: [PATCH V2] mm: compaction: update the COMPACT[STALL|FAIL] events properly Date: Fri, 12 Feb 2021 23:03:04 +0530 Message-Id: <1613151184-21213-1-git-send-email-charante@codeaurora.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By definition, COMPACT[STALL|FAIL] events needs to be counted when there is 'At least in one zone compaction wasn't deferred or skipped from the direct compaction'. And when compaction is skipped or deferred, COMPACT_SKIPPED will be returned but it will still go and update these compaction events which is wrong in the sense that COMPACT[STALL|FAIL] is counted without even trying the compaction. Correct this by skipping the counting of these events when COMPACT_SKIPPED is returned for compaction. This indirectly also avoid the unnecessary try into the get_page_from_freelist() when compaction is not even tried. There is a corner case where compaction is skipped but still count COMPACTSTALL event, which is that IRQ came and freed the page and the same is captured in capture_control. Signed-off-by: Charan Teja Reddy --- changes in V1: https://lore.kernel.org/patchwork/patch/1373665/ mm/compaction.c | 8 ++++++++ mm/page_alloc.c | 2 ++ 2 files changed, 10 insertions(+) diff --git a/mm/compaction.c b/mm/compaction.c index 190ccda..104ebef 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -2487,6 +2487,14 @@ static enum compact_result compact_zone_order(struct zone *zone, int order, */ WRITE_ONCE(current->capture_control, NULL); *capture = READ_ONCE(capc.page); + /* + * Technically, it is also possible that compaction is skipped but + * the page is still captured out of luck(IRQ came and freed the page). + * Returning COMPACT_SUCCESS in such cases helps in properly accounting + * the COMPACT[STALL|FAIL] when compaction is skipped. + */ + if (*capture) + ret = COMPACT_SUCCESS; return ret; } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 519a60d..531f244 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4152,6 +4152,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, memalloc_noreclaim_restore(noreclaim_flag); psi_memstall_leave(&pflags); + if (*compact_result == COMPACT_SKIPPED) + return NULL; /* * At least in one zone compaction wasn't deferred or skipped, so let's * count a compaction stall -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation