----- Original Message -----
> From: "Andrew Morton" <a...@linux-foundation.org>
> To: "Jan Stancek" <jstan...@redhat.com>
> Cc: linux...@kvack.org, linux-kernel@vger.kernel.org,
> n-horigu...@ah.jp.nec.com, "mike kravetz"
> <mike.krav...@oracle.com>, "hillf zj" <hillf...@alibaba-inc.com>, "kirill
> shutemov"
> <kirill.shute...@linux.intel.com>, "dave hansen"
> <dave.han...@linux.intel.com>, "paul gortmaker"
> <paul.gortma...@windriver.com>
> Sent: Friday, 4 March, 2016 10:38:07 PM
> Subject: Re: [PATCH] mm/hugetlb: use EOPNOTSUPP in hugetlb sysctl handlers
>
> On Thu, 3 Mar 2016 11:02:51 +0100 Jan Stancek <jstan...@redhat.com> wrote:
>
> > Replace ENOTSUPP with EOPNOTSUPP. If hugepages are not supported,
> > this value is propagated to userspace. EOPNOTSUPP is part of uapi
> > and is widely supported by libc libraries.
>
> hm, what is the actual user-visible effect of this change? Does it fix
> some misbehaviour?
>
It gives nicer message to user, rather than:
# cat /proc/sys/vm/nr_hugepages
cat: /proc/sys/vm/nr_hugepages: Unknown error 524
And also LTP's proc01 test was failing because this ret code (524)
was unexpected:
proc01 1 TFAIL : proc01.c:396: read failed: /proc/sys/vm/nr_hugepages:
errno=???(524): Unknown error 524
proc01 2 TFAIL : proc01.c:396: read failed:
/proc/sys/vm/nr_hugepages_mempolicy: errno=???(524): Unknown error 524
proc01 3 TFAIL : proc01.c:396: read failed:
/proc/sys/vm/nr_overcommit_hugepages: errno=???(524): Unknown error 524
Regards,
Jan
