From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 19 Apr 2018 12:30:36 -0400 From: Jerome Glisse To: Matthew Wilcox Cc: Dave Chinner , linux-mm@kvack.org, lsf-pc@lists.linux-foundation.org, linux-fsdevel , linux-block@vger.kernel.org, Johannes Weiner , Michal Hocko Subject: Re: [LSF/MM] schedule suggestion Message-ID: <20180419163036.GC3519@redhat.com> References: <20180418211939.GD3476@redhat.com> <20180419015508.GJ27893@dastard> <20180419143825.GA3519@redhat.com> <20180419144356.GC25406@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180419144356.GC25406@bombadil.infradead.org> Sender: owner-linux-mm@kvack.org List-ID: On Thu, Apr 19, 2018 at 07:43:56AM -0700, Matthew Wilcox wrote: > On Thu, Apr 19, 2018 at 10:38:25AM -0400, Jerome Glisse wrote: > > Oh can i get one more small slot for fs ? I want to ask if they are > > any people against having a callback everytime a struct file is added > > to a task_struct and also having a secondary array so that special > > file like device file can store something opaque per task_struct per > > struct file. > > Do you really want something per _thread_, and not per _mm_? Well per mm would be fine but i do not see how to make that happen with reasonable structure. So issue is that you can have multiple task with same mm but different file descriptors (or am i wrong here ?) thus there would be no easy way given a struct file to lookup the per mm struct. So as a not perfect solution i see a new array in filedes which would allow device driver to store a pointer to their per mm data structure. To be fair usualy you will only have a single fd in a single task for a given device. If you see an easy way to get a per mm per inode pointer store somewhere with easy lookup i am all ears :) Cheers, J�r�me