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From:   Pavel Tatashin <pasha.tatashin@soleen.com>
Date:   Thu, 15 Jul 2021 14:10:33 -0400
Message-ID: <CA+CK2bCzn8BVOH2pB4=MPyyDN9KeoWRmQ=GYq25R1zDKibuEeg@mail.gmail.com>
Subject: Re: [PATCH 2/2] mm: KSM: fix data type
To:     Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Tyler Hicks <tyhicks@linux.microsoft.com>,
        linux-mm <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Thu, Jul 15, 2021 at 2:01 PM Zhansaya Bagdauletkyzy
<zhansayabagdaulet@gmail.com> wrote:
>
> ksm_stable_node_chains_prune_millisecs is declared as int, but in
> stable__node_chains_prune_millisecs_store(), it can store values up to
> UINT_MAX. Change the variable type to unsigned int.
>
> Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
> ---
>  mm/ksm.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 057d0c245bf4..2e4bd7662e52 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -259,7 +259,7 @@ static unsigned long ksm_stable_node_chains;
>  static unsigned long ksm_stable_node_dups;
>
>  /* Delay in pruning stale stable_node_dups in the stable_node_chains */
> -static int ksm_stable_node_chains_prune_millisecs = 2000;
> +static unsigned int ksm_stable_node_chains_prune_millisecs = 2000;
>
>  /* Maximum number of page slots sharing a stable node */
>  static int ksm_max_page_sharing = 256;
> @@ -3105,11 +3105,11 @@ stable_node_chains_prune_millisecs_store(struct kobject *kobj,
>                                          struct kobj_attribute *attr,
>                                          const char *buf, size_t count)
>  {
> -       unsigned long msecs;
> +       unsigned int msecs;
>         int err;
>
> -       err = kstrtoul(buf, 10, &msecs);
> -       if (err || msecs > UINT_MAX)
> +       err = kstrtouint(buf, 10, &msecs);
> +       if (err)
>                 return -EINVAL;
>
>         ksm_stable_node_chains_prune_millisecs = msecs;

LGTM, but I would merge the two patches together. They both update
types of sysfs tunnables in the same file.

Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>


> --
> 2.25.1
>