lkml.org 
[lkml]   [2019]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH RFC 00/10] RDMA/FS DAX truncate proposal
    On Thu, Jun 06, 2019 at 10:11:58AM -0700, Ira Weiny wrote:

    > 2) This is a bit more subtle and something I almost delayed sending these out
    > for. Currently the implementation of a lease break actually removes the
    > lease from the file. I did not want this to happen and I was thinking of
    > delaying this patch set to implement something which keeps the lease around
    > but I figured I should get something out for comments. Jan has proposed
    > something along these lines and I agree with him so I'm going to ask you to
    > read my response to him about the details.
    >
    >
    > Anyway so the key here is that currently an app needs the SIGIO to retake
    > the lease if they want to map the file again or in parts based on usage.
    > For example, they may only want to map some of the file for when they are
    > using it and then map another part later. Without the SIGIO they would lose
    > their lease or would have to just take the lease for each GUP pin (which
    > adds overhead). Like I said I did not like this but I left it to get
    > something which works out.

    So to be clear..

    Even though the lease is broken the GUP remains, the pages remain
    pined, and truncate/etc continues to fail?

    I like Jan's take on this actually.. see other email.

    Jason

    \
     
     \ /
      Last update: 2019-06-06 21:47    [W:5.118 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site