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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B8D0C7618E for ; Fri, 21 Apr 2023 15:35:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232308AbjDUPfH (ORCPT ); Fri, 21 Apr 2023 11:35:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229935AbjDUPfF (ORCPT ); Fri, 21 Apr 2023 11:35:05 -0400 Received: from mail-qv1-xf2a.google.com (mail-qv1-xf2a.google.com [IPv6:2607:f8b0:4864:20::f2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1457040D8 for ; Fri, 21 Apr 2023 08:35:04 -0700 (PDT) Received: by mail-qv1-xf2a.google.com with SMTP id 6a1803df08f44-5ef51c44141so10237206d6.2 for ; Fri, 21 Apr 2023 08:35:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20221208.gappssmtp.com; s=20221208; t=1682091303; x=1684683303; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=AIwc2EwMoi2Tn8izgV4+Oz6B5LB65bXuCsFCTBVkivA=; b=p46jR/2aVJ2uuWmw/MXDI1Bw0f8UBaTgoMrk4pt6iKCrL9SVUq8FNMpvaMf/q8MVmg HNw0sTRu87WY3YOHQ98z/CBUOc2QtL0XQBD9EskNE3OIoIh+cpLEsHtZI0yEObQDFBhj 5f4+3re4Y4n6ztZ6B0XBnRhHyIQ/0a8c0mj2D3VymBJMxJJRNBQm7II5R7mILjp/5wgo AjZJ6WoIXS7D3kqqKI6sEnDtQHuLulHE1790VNTugUTainUef9mdTzSBM0mF2l4+J4Tr RDeu6ernIEcm2e3aijuIrwuybZgRywzldQ6kAPGIOgMAGKQJ4SREXTL8Gb7Q69C1XewD NNXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1682091303; x=1684683303; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=AIwc2EwMoi2Tn8izgV4+Oz6B5LB65bXuCsFCTBVkivA=; b=QAs+6mL0hbTkN2SjByC48Et+p8ffb1PZglcc44xKMuTxwxsjQy79tQuzt2kimSbuqN NhIdOLpvW0Ov9QXVDwx2z3hLyZv/Q4aDfaTChKFuFToUAkY13p4UKgVVI61Dp6VkfX2I qLvWskG4XSLPhzv0BwWuwOZz8eFv1rXH8XI1pFOV4yTSaqCsdePcf2xUr1hqVHGCAuhc CDZzzO2PMz0VXNksPa11VTva0wCneij5MFhurBo/by+lbS0uk55j9mo/eeMrmfxHF3Ra AhXN0uwIpfxXz27I6+qwF3XdfmwRoMQ3L8hbGhsP8iZQZB+1AVnhkdr0jPeVYpZnAi30 VXrw== X-Gm-Message-State: AAQBX9eAs3UtfnCFmd8jq9VyAXlDyzMKsQgZv8Oe9sFdugekk+h9mKSx s8Kq562jsUE72MTT09YTQvWBcSm+Bug6pPjgPFs= X-Google-Smtp-Source: AKy350ZwdA+v1rN8c74PIN9+mxpgKKx34vtCEgUKJxx7MVUc0wFWqwCTLswvulkzoZyCh1F2bg589Q== X-Received: by 2002:a05:6214:d6e:b0:5ee:2789:15f9 with SMTP id 14-20020a0562140d6e00b005ee278915f9mr11262767qvs.16.1682091302909; Fri, 21 Apr 2023 08:35:02 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:6f0d]) by smtp.gmail.com with ESMTPSA id oj2-20020a056214440200b005ef593385e3sm1249813qvb.1.2023.04.21.08.35.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Apr 2023 08:35:02 -0700 (PDT) Date: Fri, 21 Apr 2023 11:35:01 -0400 From: Johannes Weiner To: Mel Gorman Cc: linux-mm@kvack.org, Kaiyang Zhao , Vlastimil Babka , David Rientjes , linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [RFC PATCH 12/26] mm: page_alloc: per-migratetype free counts Message-ID: <20230421153501.GE320347@cmpxchg.org> References: <20230418191313.268131-1-hannes@cmpxchg.org> <20230418191313.268131-13-hannes@cmpxchg.org> <20230421142841.parju3gmqmpefigq@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230421142841.parju3gmqmpefigq@techsingularity.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 21, 2023 at 03:28:41PM +0100, Mel Gorman wrote: > On Tue, Apr 18, 2023 at 03:12:59PM -0400, Johannes Weiner wrote: > > Increase visibility into the defragmentation behavior by tracking and > > reporting per-migratetype free counters. > > > > Subsequent patches will also use those counters to make more targeted > > reclaim/compaction decisions. > > > > Signed-off-by: Johannes Weiner > > Visibility into fragmentation behaviour is information that is > almost certainly only useful to a developer and even then, there is > /proc/pagetypeinfo. At minimum, move this patch to later in the series > but I'm skeptical about its benefit. Having them available in the memory dump (OOM, sysrq) was essential while debugging problems in later patches. For OOMs or lockups, pagetypeinfo isn't available. It would be useful to have them included in user reports if any issues pop up. They're used internally in several places later on, too. I'll expand on the changelog and move them ahead in the series. Thanks