From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Hrubis Date: Tue, 7 Jun 2016 18:09:24 +0200 Subject: [LTP] [PATCH] proc01: handle EOPNOTSUPP if !hugepages_supported() In-Reply-To: References: Message-ID: <20160607160924.GA5810@rei> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Hi! > This patch adds an entry to known issue list. These 2 proc files > may return EOPNOTSUPP if CONFIG_HUGETLB_PAGE=Y and hugepages_supported() > is false: > /proc/sys/vm/nr_hugepages: errno=EOPNOTSUPP(95): Operation not supported > /proc/sys/vm/nr_overcommit_hugepages: errno=EOPNOTSUPP(95): Operation not supported > > from mm/hugetlb.c: > --------------------------------- 8< --------------------------------- > static int hugetlb_sysctl_handler_common(bool obey_mempolicy, > struct ctl_table *table, int write, > void __user *buffer, size_t *length, loff_t *ppos) > { > struct hstate *h = &default_hstate; > unsigned long tmp = h->max_huge_pages; > int ret; > > if (!hugepages_supported()) > return -EOPNOTSUPP; > --------------------------------- >8 --------------------------------- > > I've noticed this issue on s390 only after this commit: > commit 7f9be77555bb2e52de84e9dddf7b4eb20cc6e171 > Author: Dominik Dingel > Date: Fri Jul 17 16:23:39 2015 -0700 > s390/hugetlb: add hugepages_supported define > > Also note, that kernel versions prior to 4.4 may fail with > ENOTSUPP, which has been changed to EOPNOTSUPP by: > commit 86613628b3d367743f71b945c203774c522404f4 > Author: Jan Stancek > Date: Wed Mar 9 14:08:35 2016 -0800 > mm/hugetlb: use EOPNOTSUPP in hugetlb sysctl handlers > > Given that nobody complained running into this issue before, > it's assumed that this is not common and therefore this patch > adds only EOPNOTSUPP to list. I've stumbled upon this failure as well, I was about to prod you to submit exactly this patch. Acked, and thanks :). -- Cyril Hrubis chrubis@suse.cz