From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f50.google.com (mail-oo1-f50.google.com [209.85.161.50]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 786DD1494AC for ; Fri, 5 Jul 2024 11:09:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720177744; cv=none; b=JpDRNmc87pokAXWigheoOHFrLgG/Kj0usR6hLnU1Lbfi20clxtm+7EiuPskrQRiS5wbh6Yhn1iLAGX1Ztw5xfnqYdeo3NmhFOMvhJ2O82K0kWuahE+F/SE7Dv9S3q75doLNFgef9zLakIirvbhZ4ImVLiYPFP5cuzZKVUJ+NJ14= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720177744; c=relaxed/simple; bh=fDulRA5wY27E8BaQYB2UM7S3YsQRO7WeRgkJ8bJUNC8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P3Qb9xPbP/X+0LQAOI1asshlupqd8k8Gv/8AEeTgE7kdRRHotk7sXKqQBzC5GojNN/8v66+klZh09YSsrbUYLmIOWvCvLD2FcSw9TmJDJe1qqL4QQVzuqByJD7btEIMM+eUOQ1MlJ/bE0O3lBK/3eW++jdtc3U3QzHDbW8Uj/bw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=mwH/bVZA; arc=none smtp.client-ip=209.85.161.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mwH/bVZA" Received: by mail-oo1-f50.google.com with SMTP id 006d021491bc7-5c219c54800so722686eaf.0 for ; Fri, 05 Jul 2024 04:09:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720177742; x=1720782542; darn=vger.kernel.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=6WzC+hRRvf2EydJkKilHZ95nPy417tV+PTrQEse7qlk=; b=mwH/bVZA0u3DKar1M2H32KFVMnFdQDEaq1b8yXXW64uf6ONMt5aAfYhN149AhXE7FR t6yW95ZtvPt+fbeWR8yAIR5nESSExFrkN2OXml309zRk3MJeUy16wXRfmeCqMiNq5mjz cXmvkjXpvwflH0jsphf5zrsS4yzRa4XiVEUf1oGCIOx1X7+VU7MDpOQM9A1kawRv35OV Cbq1Jm9uO1mwsi3Np9TW2SJmHuBRdIVg7AZxvv4WRsZ3qbA8kIfhhpfzsdO3byzM5TY9 gsESYaidv/sxWv/YFgcAyZsxKAEaelyQsccChPeh9UgWY9hbrJdg23V7pRhTdzuFSTKb yZZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720177742; x=1720782542; 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=6WzC+hRRvf2EydJkKilHZ95nPy417tV+PTrQEse7qlk=; b=loi9pSWcV4XI4BLOZMfHdNA6DOoVbM5sAfSejRmuWMwtKZzEJvVnVx0F2YL66vjwRv POZ8wldKlFsTmsHDXKhZ//AfXyP3FUDyFe8f1E9fQiJ3ro64e11xifxH/E5bU3fXM07y z3ZFgN6A8UDRs+xHsytOJ/lenF1oM+dDEEbK+hW12k09XWFCip3SPH/i66X17rzRr19u R38m86+Q+6yv1IfSbd/zzGTXcc51avHPdWuG0gqV+YM7Aj/JxvD3F/Ec+F+UtJfYepew rMlHWjloZFNhYMYkhGDJ7OX3WRHVK4y375iFJpvfD7wlkOC7RTJQBWMbF3vvY0cejHex fpHw== X-Forwarded-Encrypted: i=1; AJvYcCU0k7QbgavUc/L4Xv01pCY/oi6YOdfjg1ignUWtW1gZu/Nsn2xO3mbKfkEeW5OdBvsWtriE+4ePtLEILebm8oqYjO73Zxugz7NB/5Wa X-Gm-Message-State: AOJu0Yw/hwqdyT2CR4nmMEW8drbC4VwQKk9o1aV3VJUS0rifVfXiLKeX F0hjqvBnY7l3JlM1D3z2vJQHLmVZWnmG/+rh5cvHAlk8xC5xDAEq X-Google-Smtp-Source: AGHT+IHzeICS1oNqqYW7D/8f6xEgQJzXIS/jUrkrbvOuSduc2b9TuE9ZL7Q4J8OXY322Cju933uguQ== X-Received: by 2002:a05:6870:171e:b0:24c:ae57:b4b9 with SMTP id 586e51a60fabf-25e2bb3d366mr4061569fac.14.1720177742409; Fri, 05 Jul 2024 04:09:02 -0700 (PDT) Received: from EBJ9932692.tcent.cn ([43.129.202.66]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70b0238331csm2714112b3a.170.2024.07.05.04.08.58 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 05 Jul 2024 04:09:01 -0700 (PDT) From: Lance Yang To: david@redhat.com Cc: 21cnbao@gmail.com, akpm@linux-foundation.org, baohua@kernel.org, baolin.wang@linux.alibaba.com, dj456119@gmail.com, ioworker0@gmail.com, libang.li@antgroup.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mingzhe.yang@ly.com, ryan.roberts@arm.com, shy828301@gmail.com, ziy@nvidia.com Subject: Re: [PATCH v3 2/2] mm: add docs for per-order mTHP split counters Date: Fri, 5 Jul 2024 19:08:16 +0800 Message-ID: <20240705110816.75871-1-ioworker0@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <40ba1239-bbe2-470b-8574-c7e098b40bc7@redhat.com> References: <40ba1239-bbe2-470b-8574-c7e098b40bc7@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi David and Ryan, Thanks for taking time to review! Updated the doc. How about the following? 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. 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, if splitting is possible. Thanks, Lance