----- Original Message ----- > From: "Andrew Morton" <akpm@xxxxxxxxxxxxxxxxxxxx> > To: "Jan Stancek" <jstancek@xxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, n-horiguchi@xxxxxxxxxxxxx, "mike kravetz" > <mike.kravetz@xxxxxxxxxx>, "hillf zj" <hillf.zj@xxxxxxxxxxxxxxx>, "kirill shutemov" > <kirill.shutemov@xxxxxxxxxxxxxxx>, "dave hansen" <dave.hansen@xxxxxxxxxxxxxxx>, "paul gortmaker" > <paul.gortmaker@xxxxxxxxxxxxx> > 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 <jstancek@xxxxxxxxxx> 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>