From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Metcalf Subject: Re: [PATCH V3 4/5] mm: mmap: Add mmap flag to request VM_LOCKONFAULT Date: Mon, 20 Jul 2015 16:40:25 -0400 Message-ID: <55AD5CB9.4090400@ezchip.com> References: <1436288623-13007-1-git-send-email-emunson@akamai.com> <1436288623-13007-5-git-send-email-emunson@akamai.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-arch-owner@vger.kernel.org To: Paul Gortmaker , Eric B Munson Cc: Andrew Morton , Michal Hocko , Vlastimil Babka , LKML , linux-mm@kvack.org, linux-arch , linux-api@vger.kernel.org, "linux-next@vger.kernel.org" List-Id: linux-next.vger.kernel.org On 07/18/2015 03:11 PM, Paul Gortmaker wrote: > On Tue, Jul 7, 2015 at 1:03 PM, Eric B Munson wrote: >> >The cost of faulting in all memory to be locked can be very high when >> >working with large mappings. If only portions of the mapping will be >> >used this can incur a high penalty for locking. >> > >> >Now that we have the new VMA flag for the locked but not present state, >> >expose it as an mmap option like MAP_LOCKED -> VM_LOCKED. > An automatic bisection on arch/tile leads to this commit: > > 5a5656f2c9b61c74c15f9ef3fa2e6513b6c237bb is the first bad commit > commit 5a5656f2c9b61c74c15f9ef3fa2e6513b6c237bb > Author: Eric B Munson > Date: Thu Jul 16 10:09:22 2015 +1000 > > mm: mmap: add mmap flag to request VM_LOCKONFAULT Eric, I'm happy to help with figuring out the tile issues. -- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com