From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-vk1-f175.google.com (mail-vk1-f175.google.com [209.85.221.175]) (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 59327387 for ; Mon, 1 Jul 2024 00:02:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719792149; cv=none; b=NgB9jThJGLqAKW+DODpSSLX7Dk70kFzZpwy8hl2pN0wMfyNFvl3jE900LL1vL4N694Ib7DjzmBfixAZCVK6bDwpCz2rqKI69CPPOsSVWsNgcZGEeen6oGhMnmsf2TneqGXTHGbyZsacNo9E0fNMpCiz3EJesEbc51roiakR9d9M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719792149; c=relaxed/simple; bh=NbgkfrTDAiPMFVVs0YSeT9ayus6njpTHVQtt6B8eRv8=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=dj2/geH9igHIRdT9CGgN83YPfGKYSKgRixRltxSt+qJ8IpuFpjOFEmMt4no7YYzO/M7oW5IJwcKfKaBHV/t68C7xvQYHYSe0AK5LGel/fwkSzc5fRlUyUXM7R9611cLb9x10UnHs2UyCQGegZFxS91xn6j/I9MXRojEM93qhCUw= 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=aDXfrCLr; arc=none smtp.client-ip=209.85.221.175 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="aDXfrCLr" Received: by mail-vk1-f175.google.com with SMTP id 71dfb90a1353d-4ef5f4e3f56so768767e0c.3 for ; Sun, 30 Jun 2024 17:02:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1719792145; x=1720396945; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=bhN9AvD496DDfdjwo2Jpu2JMzYfWFg3K+lNbZSu8nz0=; b=aDXfrCLrrz7BVYZReKrHtqYIberssV2zlyF+ITBlzS8vN06+DUQNs6rDQYC9M84SPo TgU+qHh0gfPHjpbVrQgtf0xqkKesfqyN8Sk/Of4yI7L5XYxCKAapwNpj2zwqWHR5wukg 0qxPrJJkdhb/5yS82DUtKmQakmvHttN85TZLmW0l4C9s0DPq34ViF13a3gC5H1DdJX95 8/6NY1vx2oZHFsdCLscl6br+18LT4cSe4ca1pdFgcWjmDcd432AslKm8uEIvJgpNzR8m /nkPlWjkLvIogi0LBGmK+fkgNip9QeFqCozWldnHs5+hj8W6e2YulbNH1WLMWr3tanh5 puZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719792145; x=1720396945; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bhN9AvD496DDfdjwo2Jpu2JMzYfWFg3K+lNbZSu8nz0=; b=MGzFZ/75PuQmBVuVx8JIOkqgjPjkRzypFT8vDehdno5DN9cipS+PyZQHYXTzeB1vmT HtggLiiE2eoaZI8XhJKOa1MTBzQ8fSXpB3AmNDebf50XoEVvEjLIQnuvHeyouErFb4vC ST+qktwIYkaxH4tGaLRgv5yjSIoRvUPlpbkD/yCoFgwqkRUIUkpN59AugdFajoLIUZvV YWst85/X9wgi9CxjvH1DldWSUOXkNPAXftTcV6T8MTwG/vlD3pzA3OXxkByssXgGWE+w evqLil4DA74FBueZF2YVyGtvu35cwXZY4RxSlSK0C0cWRQKDkjA1U7ks0onqADdxV+2o QcTA== X-Forwarded-Encrypted: i=1; AJvYcCUlfmfV4GWsS21FUSSXMcyToRfeIKhtsLP2TPjiLXne7l5fHz3kzEHgY0Wrd94gFn9PhtwL7pdfGSIyQNehctObA4g/trVC6IEkzBK3 X-Gm-Message-State: AOJu0YwVh4Y++lCDm1MaTcDTx/cPiKIXNk9y3EP1YqFY6WSNvCAGtFvy blXxDMPG15R5wUDsUNjwCOOmHFLlBo530AOP6bTNC9gRIYzKPpNQ+ZGbWSPGHkdE6+PGx5ZWYNo LENCFENevYdJXsXSThqgDUDfANWU= X-Google-Smtp-Source: AGHT+IFkYOZAIccehM4mD5dWvZy3ssCMdsjnZYfbVnoRIM94K1dOA5MX7p4didYbA0msMSHMQoipe2OMdh8UBaXpttc= X-Received: by 2002:a05:6122:1b85:b0:4ef:6b47:3570 with SMTP id 71dfb90a1353d-4f2a56addcbmr5108954e0c.8.1719792145192; Sun, 30 Jun 2024 17:02:25 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20240628130750.73097-1-ioworker0@gmail.com> <20240628130750.73097-2-ioworker0@gmail.com> In-Reply-To: <20240628130750.73097-2-ioworker0@gmail.com> From: Barry Song <21cnbao@gmail.com> Date: Mon, 1 Jul 2024 12:02:14 +1200 Message-ID: Subject: Re: [PATCH v2 1/2] mm: add per-order mTHP split counters To: Lance Yang Cc: akpm@linux-foundation.org, dj456119@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, Mingzhe Yang Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, Jun 29, 2024 at 1:09=E2=80=AFAM Lance Yang wr= ote: > > Currently, the split counters in THP statistics no longer include > PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split > counters to monitor the frequency of mTHP splits. This will help develope= rs > better analyze and optimize system performance. > > /sys/kernel/mm/transparent_hugepage/hugepages-/stats > split > split_failed > split_deferred > > Signed-off-by: Mingzhe Yang > Signed-off-by: Lance Yang Personally, I'm not convinced that using a temporary variable order makes the code more readable. Functions like folio_test_pmd_mappable() seem more readable = to me. In any case, it's a minor issue. Acked-by: Barry Song > --- > include/linux/huge_mm.h | 3 +++ > mm/huge_memory.c | 19 ++++++++++++++----- > 2 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 212cca384d7e..cee3c5da8f0e 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -284,6 +284,9 @@ enum mthp_stat_item { > MTHP_STAT_FILE_ALLOC, > MTHP_STAT_FILE_FALLBACK, > MTHP_STAT_FILE_FALLBACK_CHARGE, > + MTHP_STAT_SPLIT, > + MTHP_STAT_SPLIT_FAILED, > + MTHP_STAT_SPLIT_DEFERRED, > __MTHP_STAT_COUNT > }; > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index c7ce28f6b7f3..a633206375af 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -559,6 +559,9 @@ DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPO= UT_FALLBACK); > DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC); > DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK); > DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_FALLBACK_CHAR= GE); > +DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT); > +DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED); > +DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED); > > static struct attribute *stats_attrs[] =3D { > &anon_fault_alloc_attr.attr, > @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] =3D { > &file_alloc_attr.attr, > &file_fallback_attr.attr, > &file_fallback_charge_attr.attr, > + &split_attr.attr, > + &split_failed_attr.attr, > + &split_deferred_attr.attr, > NULL, > }; > > @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *p= age, struct list_head *list, > XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_o= rder); > struct anon_vma *anon_vma =3D NULL; > struct address_space *mapping =3D NULL; > - bool is_thp =3D folio_test_pmd_mappable(folio); > + int order =3D folio_order(folio); > int extra_pins, ret; > pgoff_t end; > bool is_hzp; > @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *p= age, struct list_head *list, > VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); > VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); > > - if (new_order >=3D folio_order(folio)) > + if (new_order >=3D order) > return -EINVAL; > > if (folio_test_anon(folio)) { > @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *p= age, struct list_head *list, > i_mmap_unlock_read(mapping); > out: > xas_destroy(&xas); > - if (is_thp) > + if (order >=3D HPAGE_PMD_ORDER) > count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAI= LED); > + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_F= AILED); > return ret; > } > > @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio) > #ifdef CONFIG_MEMCG > struct mem_cgroup *memcg =3D folio_memcg(folio); > #endif > + int order =3D folio_order(folio); > unsigned long flags; > > /* > * Order 1 folios have no space for a deferred list, but we also > * won't waste much memory by not adding them to the deferred lis= t. > */ > - if (folio_order(folio) <=3D 1) > + if (order <=3D 1) > return; > > /* > @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio) > > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > if (list_empty(&folio->_deferred_list)) { > - if (folio_test_pmd_mappable(folio)) > + if (order >=3D HPAGE_PMD_ORDER) > count_vm_event(THP_DEFERRED_SPLIT_PAGE); > + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED); > list_add_tail(&folio->_deferred_list, &ds_queue->split_qu= eue); > ds_queue->split_queue_len++; > #ifdef CONFIG_MEMCG > -- > 2.45.2 >