From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Date: Thu, 20 Oct 2016 19:26:47 +0000 Subject: Re: [PATCH 00/10] mm: adjust get_user_pages* functions to explicitly pass FOLL_* flags Message-Id: <20161020192646.GC27342@dhcp22.suse.cz> List-Id: References: <20161013002020.3062-1-lstoakes@gmail.com> <20161018153050.GC13117@dhcp22.suse.cz> <20161019085815.GA22239@lucifer> <20161019090727.GE7517@dhcp22.suse.cz> <5807A427.7010200@linux.intel.com> <20161019170127.GN24393@dhcp22.suse.cz> <5807AC2B.4090208@linux.intel.com> In-Reply-To: <5807AC2B.4090208@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dave Hansen Cc: Lorenzo Stoakes , linux-mm@kvack.org, Linus Torvalds , Jan Kara , Hugh Dickins , Rik van Riel , Mel Gorman , Andrew Morton , adi-buildroot-devel@lists.sourceforge.net, ceph-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cris-kernel@axis.com, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@linux-mips.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, linux-samsung-soc@vg On Wed 19-10-16 10:23:55, Dave Hansen wrote: > On 10/19/2016 10:01 AM, Michal Hocko wrote: > > The question I had earlier was whether this has to be an explicit FOLL > > flag used by g-u-p users or we can just use it internally when mm !> > current->mm > > The reason I chose not to do that was that deferred work gets run under > a basically random 'current'. If we just use 'mm != current->mm', then > the deferred work will sometimes have pkeys enforced and sometimes not, > basically randomly. OK, I see (async_pf_execute and ksm ). It makes more sense to me. Thanks for the clarification. -- Michal Hocko SUSE Labs