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Date: Sun, 20 Sep 2015 12:58:28 +0200
From: Michal Hocko <mhocko@kernel.org>
To: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        =?iso-8859-1?Q?P=E1draig?= Brady <P@draigBrady.com>,
        David Rientjes <rientjes@google.com>,
        =?iso-8859-1?Q?J=F6rn?= Engel <joern@purestorage.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Naoya Horiguchi <nao.horiguchi@gmail.com>
Subject: Re: [PATCH v6 2/2] mm: hugetlb: proc: add HugetlbPages field to
 /proc/PID/status
Message-ID: <20150920105828.GB20562@dhcp22.suse.cz>
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On Thu 17-09-15 09:09:31, Naoya Horiguchi wrote:
> Currently there's no easy way to get per-process usage of hugetlb pages, which
> is inconvenient because userspace applications which use hugetlb typically want
> to control their processes on the basis of how much memory (including hugetlb)
> they use. So this patch simply provides easy access to the info via
> /proc/PID/status.

Thank you for making this much more lightweight. If we ever have a
request for a per-size breakdown we can add HugetlbPages-$size: value kB

> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Acked-by: Joern Engel <joern@logfs.org>
> Acked-by: David Rientjes <rientjes@google.com>

Acked-by: Michal Hocko <mhocko@suse.com>

Just a small nit-pick, feel free to ignore if this was really intended:

[...]
> +static inline void hugetlb_count_add(long l, struct mm_struct *mm)
> +{
> +	atomic_long_add(l, &mm->hugetlb_usage);
> +}
> +
> +static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
> +{
> +	atomic_long_sub(l, &mm->hugetlb_usage);
> +}

I can see why you didn't use dec_mm_counter but the ordering could be
same. Other functions which handle counters follow the same template
(target, counter/count).

-- 
Michal Hocko
SUSE Labs