From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4517C1C174D for ; Tue, 3 Sep 2024 01:15:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725326148; cv=none; b=OsSQbr+JxjloRYFIPUUrPalM5thZUIU9A76z7/i3HH412KoPFQ1jc7GJRVcSmrlHNLoq5Mcfvex2fCRru8IZmBhBoGZHP1Ha3ixtB+0RIRg0Yt8EBXjJz2eS4/lxlzWVXql/SUFhsOOWbQh1Guru8UOYrTvK3/qT9JdwNNqNS0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725326148; c=relaxed/simple; bh=nfx7D0zsq28pLuNZTHDsKrLG9WMaMYzbv0T8g3h6xr8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sh3fN6IBzeMIYDRQB8AQIxhXtffw2Ke1T3ShAhHprIHXBxRECauHFFGjY1BC6c63/RN13lOVMa4ww78qNX4HjidPVG/HcKFUMIfbYmNx4zSKQD1ffbJtn3TnE/FRaFqliZXm2y8usfex+LRY2oNep0iNYIw9BD0Kjx7Jwn8mWKQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=wh03pPVH; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="wh03pPVH" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1725326142; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=TzlklaidYy3eFIkRP9DWHLpTDbs7aAqmDcAR3JaO49M=; b=wh03pPVHTg06ElxYcxYZJebEKwcg9D0/h5RGctNqpNK0Wy6oSM/Woxr5Ipw6lO4bi9SmLTyfDgHea6NOTjAJbQ89kJAN8fChsNOQvbla60oIlxSjjnIChvN1YMMX6TlWFRTjtoBSa6bsVuGpTSE0YQT4CR0Dmkbbn5iCJFstw7w= Received: from 30.74.144.108(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0WEBErgJ_1725326141) by smtp.aliyun-inc.com; Tue, 03 Sep 2024 09:15:41 +0800 Message-ID: Date: Tue, 3 Sep 2024 09:15:39 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] mm: Tidy up shmem mTHP controls and stats To: Ryan Roberts , Andrew Morton , Hugh Dickins , "Matthew Wilcox (Oracle)" , David Hildenbrand , Barry Song , Lance Yang , Gavin Shan Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20240808111849.651867-1-ryan.roberts@arm.com> <20240808111849.651867-3-ryan.roberts@arm.com> <747d1319-f746-4379-bf88-a0f6c3f558b4@linux.alibaba.com> <14823123-79e3-4c7d-8501-8c46c6ec13c7@arm.com> From: Baolin Wang In-Reply-To: <14823123-79e3-4c7d-8501-8c46c6ec13c7@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/9/2 17:58, Ryan Roberts wrote: > Hi Baolin, > > Thanks for the review - I've been out on Paternity leave so only getting around > to replying now... No worries :) > On 09/08/2024 09:31, Baolin Wang wrote: >> >> >> On 2024/8/8 19:18, Ryan Roberts wrote: >>> Previously we had a situation where shmem mTHP controls and stats were >>> not exposed for some supported sizes and were exposed for some >>> unsupported sizes. So let's clean that up. >>> >>> Anon mTHP can support all large orders [2, PMD_ORDER]. But shmem can >>> support all large orders [1, MAX_PAGECACHE_ORDER]. However, per-size >>> shmem controls and stats were previously being exposed for all the anon >>> mTHP orders, meaning order-1 was not present, and for arm64 64K base >>> pages, orders 12 and 13 were exposed but were not supported internally. >>> >>> Tidy this all up by defining ctrl and stats attribute groups for anon >>> and file separately. Anon ctrl and stats groups are populated for all >>> orders in THP_ORDERS_ALL_ANON and file ctrl and stats groups are >>> populated for all orders in THP_ORDERS_ALL_FILE_DEFAULT. >>> >>> Additionally, create "any" ctrl and stats attribute groups which are >>> populated for all orders in (THP_ORDERS_ALL_ANON | >>> THP_ORDERS_ALL_FILE_DEFAULT). swpout stats use this since they apply to >>> anon and shmem. >>> >>> The side-effect of all this is that different hugepage-*kB directories >>> contain different sets of controls and stats, depending on which memory >>> types support that size. This approach is preferred over the >>> alternative, which is to populate dummy controls and stats for memory >>> types that do not support a given size. >>> >>> Signed-off-by: Ryan Roberts >>> --- >>>   mm/huge_memory.c | 144 +++++++++++++++++++++++++++++++++++++---------- >>>   1 file changed, 114 insertions(+), 30 deletions(-) >>> >>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>> index 0c3075ee00012..082d86b7c6c2f 100644 >>> --- a/mm/huge_memory.c >>> +++ b/mm/huge_memory.c >>> @@ -482,8 +482,8 @@ static void thpsize_release(struct kobject *kobj); >>>   static DEFINE_SPINLOCK(huge_anon_orders_lock); >>>   static LIST_HEAD(thpsize_list); >>>   -static ssize_t thpsize_enabled_show(struct kobject *kobj, >>> -                    struct kobj_attribute *attr, char *buf) >>> +static ssize_t anon_enabled_show(struct kobject *kobj, >>> +                 struct kobj_attribute *attr, char *buf) >>>   { >>>       int order = to_thpsize(kobj)->order; >>>       const char *output; >>> @@ -500,9 +500,9 @@ static ssize_t thpsize_enabled_show(struct kobject *kobj, >>>       return sysfs_emit(buf, "%s\n", output); >>>   } >>>   -static ssize_t thpsize_enabled_store(struct kobject *kobj, >>> -                     struct kobj_attribute *attr, >>> -                     const char *buf, size_t count) >>> +static ssize_t anon_enabled_store(struct kobject *kobj, >>> +                  struct kobj_attribute *attr, >>> +                  const char *buf, size_t count) >>>   { >>>       int order = to_thpsize(kobj)->order; >>>       ssize_t ret = count; >>> @@ -544,19 +544,35 @@ static ssize_t thpsize_enabled_store(struct kobject *kobj, >>>       return ret; >>>   } >>>   -static struct kobj_attribute thpsize_enabled_attr = >>> -    __ATTR(enabled, 0644, thpsize_enabled_show, thpsize_enabled_store); >>> +static struct kobj_attribute anon_enabled_attr = >>> +    __ATTR(enabled, 0644, anon_enabled_show, anon_enabled_store); >>>   -static struct attribute *thpsize_attrs[] = { >>> -    &thpsize_enabled_attr.attr, >>> +static struct attribute *anon_ctrl_attrs[] = { >>> +    &anon_enabled_attr.attr, >>> +    NULL, >>> +}; >>> + >>> +static const struct attribute_group anon_ctrl_attr_grp = { >>> +    .attrs = anon_ctrl_attrs, >>> +}; >>> + >>> +static struct attribute *file_ctrl_attrs[] = { >>>   #ifdef CONFIG_SHMEM >>>       &thpsize_shmem_enabled_attr.attr, >>>   #endif >>>       NULL, >>>   }; >>>   -static const struct attribute_group thpsize_attr_group = { >>> -    .attrs = thpsize_attrs, >>> +static const struct attribute_group file_ctrl_attr_grp = { >>> +    .attrs = file_ctrl_attrs, >>> +}; >>> + >>> +static struct attribute *any_ctrl_attrs[] = { >>> +    NULL, >>> +}; >>> + >>> +static const struct attribute_group any_ctrl_attr_grp = { >>> +    .attrs = any_ctrl_attrs, >>>   }; >> >> I wonder why adding a NULL group? > > It made everything a bit more generic and therefore extensible. Its my > preference to leave it as is, but will remove it if you insist. My preference is we should add it when necessary, but but I don't have a strong opinion. Let's see what other guys prefer, David, Barry?