From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 21 Mar 2019 01:40:49 -0700 From: Ira Weiny Subject: Re: [RESEND PATCH 0/7] Add FOLL_LONGTERM to GUP fast and use it Message-ID: <20190321084048.GA26439@iweiny-DESK2.sc.intel.com> References: <20190317183438.2057-1-ira.weiny@intel.com> <20190319151930.bab575d62fb1a33094160fe3@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190319151930.bab575d62fb1a33094160fe3@linux-foundation.org> Sender: linux-mips-owner@vger.kernel.org List-Archive: List-Post: To: Andrew Morton Cc: John Hubbard , Michal Hocko , "Kirill A. Shutemov" , Peter Zijlstra , Jason Gunthorpe , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Martin Schwidefsky , Heiko Carstens , Rich Felker , Yoshinori Sato , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Ralf Baechle , James Hogan , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, Dan Williams List-ID: On Tue, Mar 19, 2019 at 03:19:30PM -0700, Andrew Morton wrote: > On Sun, 17 Mar 2019 11:34:31 -0700 ira.weiny@intel.com wrote: > > > Resending after rebasing to the latest mm tree. > > > > HFI1, qib, and mthca, use get_user_pages_fast() due to it performance > > advantages. These pages can be held for a significant time. But > > get_user_pages_fast() does not protect against mapping FS DAX pages. > > > > Introduce FOLL_LONGTERM and use this flag in get_user_pages_fast() which > > retains the performance while also adding the FS DAX checks. XDP has also > > shown interest in using this functionality.[1] > > > > In addition we change get_user_pages() to use the new FOLL_LONGTERM flag and > > remove the specialized get_user_pages_longterm call. > > It would be helpful to include your response to Christoph's question > (http://lkml.kernel.org/r/20190220180255.GA12020@iweiny-DESK2.sc.intel.com) > in the changelog. Because if one person was wondering about this, > others will likely do so. > > We have no record of acks or reviewed-by's. At least one was missed > (http://lkml.kernel.org/r/CAOg9mSTTcD-9bCSDfC0WRYqfVrNB4TwOzL0c4+6QXi-N_Y43Vw@mail.gmail.com), > but that is very very partial. That is my bad. Sorry to Mike. And I have added him. > > This patchset is fairly DAX-centered, but Dan wasn't cc'ed! Agreed, I'm new to changing things which affect this many sub-systems and I struggled with who should be CC'ed (get_maintainer.pl returned a very large list :-(. I fear I may have cc'ed too many people, and the wrong people apparently, so that may be affecting the review... So again my apologies. I don't know if Dan is going to get a chance to put a reviewed-by on them this week but I thought I would send this note to let you know I'm not ignoring your feedback. Just waiting a bit before resending to hopefully get some more acks/reviewed bys. Thanks, Ira > > So ho hum. I'll scoop them up and shall make the above changes to the > [1/n] changelog, but we still have some work to do. >