Re: [PATCH v2] hugetlbfs: correct handling of negative input to/proc/sys/vm/nr_hugepages

From: Anton Arapov
Date: Thu Feb 24 2011 - 03:16:51 EST


On Tue, Feb 22, 2011 at 09:17:04PM +0100, Petr Holasek wrote:
> When user insert negative value into /proc/sys/vm/nr_hugepages it
> will result
> in the setting a random number of HugePages in system (can be easily showed
> at /proc/meminfo output). This patch fixes the wrong behavior so that the
> negative input will result in nr_hugepages value unchanged.
>
> v2: same fix was also done in hugetlb_overcommit_handler function
> as suggested by reviewers.
>
> Signed-off-by: Petr Holasek <pholasek@xxxxxxxxxx>
> Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
> ---
> mm/hugetlb.c | 6 ++----
> 1 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index bb0b7c1..06de5aa 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1872,8 +1872,7 @@ static int hugetlb_sysctl_handler_common(bool
> obey_mempolicy,
> unsigned long tmp;
> int ret;
>
> - if (!write)
> - tmp = h->max_huge_pages;
> + tmp = h->max_huge_pages;
>
> if (write && h->order >= MAX_ORDER)
> return -EINVAL;
> @@ -1938,8 +1937,7 @@ int hugetlb_overcommit_handler(struct
> ctl_table *table, int write,
> unsigned long tmp;
> int ret;
>
> - if (!write)
> - tmp = h->nr_overcommit_huge_pages;
> + tmp = h->nr_overcommit_huge_pages;
>
> if (write && h->order >= MAX_ORDER)
> return -EINVAL;
> --
> 1.7.1
> --
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Signed-off-by: Anton Arapov <anton@xxxxxxxxxx>

--
Anton
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