lkml.org 
[lkml]   [2019]   [Feb]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 0/6] RFC v2: mm: gup/dma tracking
    On Mon, 4 Feb 2019, Ira Weiny wrote:

    > On Mon, Feb 04, 2019 at 05:14:19PM +0000, Christopher Lameter wrote:
    > > Frankly I still think this does not solve anything.
    > >
    > > Concurrent write access from two sources to a single page is simply wrong.
    > > You cannot make this right by allowing long term RDMA pins in a filesystem
    > > and thus the filesystem can never update part of its files on disk.
    > >
    > > Can we just disable RDMA to regular filesystems? Regular filesystems
    > > should have full control of the write back and dirty status of their
    > > pages.
    >
    > That may be a solution to the corruption/crashes but it is not a solution which
    > users want to see. RDMA directly to file systems (specifically DAX) is a use
    > case we have seen customers ask for.

    DAX is a special file system that does not use writeback for the DAX
    mappings. Thus it could be an exception. And the pages are already pinned.



    \
     
     \ /
      Last update: 2019-02-05 20:31    [W:4.329 / U:0.216 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site