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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52B9EC2BD09 for ; Thu, 4 Jul 2024 01:29:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D29936B0093; Wed, 3 Jul 2024 21:29:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CD8566B0095; Wed, 3 Jul 2024 21:29:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B35D56B0096; Wed, 3 Jul 2024 21:29:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8E9A86B0093 for ; Wed, 3 Jul 2024 21:29:41 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 40C601A094A for ; Thu, 4 Jul 2024 01:29:41 +0000 (UTC) X-FDA: 82300338162.19.511470A Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) by imf19.hostedemail.com (Postfix) with ESMTP id 6F5F81A0004 for ; Thu, 4 Jul 2024 01:29:39 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Gpg1PxKo; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf19.hostedemail.com: domain of ioworker0@gmail.com designates 209.85.214.171 as permitted sender) smtp.mailfrom=ioworker0@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1720056559; a=rsa-sha256; cv=none; b=QWeuwfreAt+N0pQ/adUJkzegZ7AJLeHczMhys0E0mo6lsLmLNJE1inZKKsqtVOXc5aZp68 0y8uNufbqKViKUJpfkW7SFzvEC51rREcyb6tESONC5ZZ84jM0pxNXkIUlc1y/Jn8sJo+qv maDVzSIeNcamtQXvZUZPF5yE6pyP3WQ= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=Gpg1PxKo; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf19.hostedemail.com: domain of ioworker0@gmail.com designates 209.85.214.171 as permitted sender) smtp.mailfrom=ioworker0@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1720056559; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=BTYAZdivsHjBzXP9vp5pmO/cchsVNESwksg5bZfIdNg=; b=Kuozl+Dv0bm/NcC8hpxcap5Jrg/KKAzVvMdtm342aLZ2MLmltRe8Z0FzHtvAK/Ne+i1Eu2 uEecWWB/f7+XbmdF51Zop08PeIN+TBDvVyNKKv0lOQ+oi9z0d/nP+ctbZi14pDUuJxPv4o t7GY6c/n7vFrZplj3vIR+h02tgl3oeA= Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-1fb0d88fd25so1040985ad.0 for ; Wed, 03 Jul 2024 18:29:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720056578; x=1720661378; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=BTYAZdivsHjBzXP9vp5pmO/cchsVNESwksg5bZfIdNg=; b=Gpg1PxKoKQX3DbmBF5RaA9gR7EA0jL/KNnjWyDBXd+7Gfu88x+UF3iSq9QKIdlCg5H TDcMjQod/ASVGBde8XF4DDDP2BYq17/i5WWK8FLNJbpQ3AESFqtGJ+xkUTleMOk1iPBA o1r2tIqYOm9HljpVJDi4iPbPCg37uluF85csVbcH8F8zaMKt9VkWtLt95elnKWh+7+jc UvNXWVN0NkIrZa9AZz1FH6cDSQXhQOeaanBXEIsz/V/W1QY4CPJicfJ1g5+3qId1Y+Ql Tf/AC3lpRzWgjTx7UOgfY5CTc3w5MlRQ2QUVDW4yTJWOZyeVyyCunEoSWNTEq0u+hTjv 2cOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720056578; x=1720661378; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=BTYAZdivsHjBzXP9vp5pmO/cchsVNESwksg5bZfIdNg=; b=a5AuNf/lqZCwcOqV9s0A0o0MIkzXkI45fE+/nh7KpcZlAnBAdRkKbSLgQXgzV5lfJo Ue5ee+rlb7cpwJFqrbtJLOR0O4IpWDSOxo1iY2zuNP5ZBkQ7i/FSvj4Hg3veJjQvHYCu o26RslBoOpRLCRd2ofaqJBdzdkxULARWsSzalgcEwlvcQ2Gh2up/AA7kVvmDCL2bonK8 F8D93P6yQuXS/M7eK6HNfPCAshNifeyqgQEgV4j9LOI9eOFrylYDtoXnjOSJ12tzJITs kA//3tvv8jkTXVbsTmOKQHkrlcGjlMZxBmgPg4PsppEhXfpKj1+AnuzYvS+svS03UrBF s3xQ== X-Forwarded-Encrypted: i=1; AJvYcCWlvcrs4QPMfw74bvPGKyeqclRkyuO0Zxb7V7a8BqD0AweQ7BSoDR/UkU7qelewkHFUdcgFXFW4ur0tI9scihlEKL0= X-Gm-Message-State: AOJu0YxFmYNjX5ppBRzIqePsOGrGQYpwGW/TCUqcflhkxb+6WIRYte0c fi2LOkA+rjZXLdOBL3WtRJ3JxnidgboL3GgXzQEPP8VoTMxilO8s X-Google-Smtp-Source: AGHT+IGY0yPT+zHZTfE83IvT3tjkGOP/4CZzxM5op9vPgkY0O7Su3xXQfWK8rAUNvo6/V70lKKe6OQ== X-Received: by 2002:a17:903:8c8:b0:1f0:8c5e:ffdd with SMTP id d9443c01a7336-1fb3440b4d9mr3459145ad.4.1720056578292; Wed, 03 Jul 2024 18:29:38 -0700 (PDT) Received: from EBJ9932692.tcent.cn ([124.156.216.125]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fac153767dsm110162735ad.148.2024.07.03.18.29.34 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 03 Jul 2024 18:29:38 -0700 (PDT) From: Lance Yang To: akpm@linux-foundation.org Cc: dj456119@gmail.com, 21cnbao@gmail.com, ryan.roberts@arm.com, david@redhat.com, shy828301@gmail.com, ziy@nvidia.com, libang.li@antgroup.com, baolin.wang@linux.alibaba.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Lance Yang , Barry Song , Mingzhe Yang Subject: [PATCH v3 2/2] mm: add docs for per-order mTHP split counters Date: Thu, 4 Jul 2024 09:29:05 +0800 Message-ID: <20240704012905.42971-3-ioworker0@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240704012905.42971-1-ioworker0@gmail.com> References: <20240704012905.42971-1-ioworker0@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 6F5F81A0004 X-Stat-Signature: zutnhcb7ih9cspxdj1i1b3hfwo58gk4h X-Rspam-User: X-HE-Tag: 1720056579-334462 X-HE-Meta: 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 iffRbHCm yBkzNsrJlU6htvjA5WEytcPUHiA6DSaFibcU9+3R8hRybpkKDtA0vjuKG2/60iKIvaFlrH8PSv5WQUbnoPf2z+o/mu/54VNrrL8Abe7yMURRMTRTdkq/+yZnYmM88HbX+zXOeseTv7UEwNSZIuQB2BC1JJZktugPoO0BwXsWMmdR+jIb0KKel2+0j82AV65fKX7JdS/Fi/DpbNkZ1DLSqIysXkHIXp27HEC/LbCdC40aYfFO0O57ZfG+J6tZsTRWJh6nHWhBOpeMVvBLRP/J2yeZSle1x6LJq5xCBHkbVMBLNZqiFrrikeHk8bWGafulMAPTMxHdbnrs/Oqo/dL+BD23bufwOiR3LbrqYFm8DCCfLBtozOuf/6snte5sgkx7+gKGibEZOxzNV8xNtDAPKhAIMYryDqdwQz9UX19oVOmp2LmvMhEgF3nESLg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This commit introduces documentation for mTHP split counters in transhuge.rst. Reviewed-by: Barry Song Signed-off-by: Mingzhe Yang Signed-off-by: Lance Yang --- Documentation/admin-guide/mm/transhuge.rst | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 1f72b00af5d3..0830aa173a8b 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -369,10 +369,6 @@ also applies to the regions registered in khugepaged. Monitoring usage ================ -.. note:: - Currently the below counters only record events relating to - PMD-sized THP. Events relating to other THP sizes are not included. - The number of PMD-sized anonymous transparent huge pages currently used by the system is available by reading the AnonHugePages field in ``/proc/meminfo``. To identify what applications are using PMD-sized anonymous transparent huge @@ -514,6 +510,22 @@ file_fallback_charge falls back to using small pages even though the allocation was successful. +split + is incremented every time a huge page is successfully split into + smaller orders. This can happen for a variety of reasons but a + common reason is that a huge page is old and is being reclaimed. + This action implies splitting any block mappings into PTEs. + +split_failed + is incremented if kernel fails to split huge + page. This can happen if the page was pinned by somebody. + +split_deferred + is incremented when a huge page is put onto split + queue. This happens when a huge page is partially unmapped and + splitting it would free up some memory. Pages on split queue are + going to be split under memory pressure. + As the system ages, allocating huge pages may be expensive as the system uses memory compaction to copy data around memory to free a huge page for use. There are some counters in ``/proc/vmstat`` to help -- 2.45.2