lkml.org 
[lkml]   [2019]   [Jul]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: WARNING in __mmdrop
    From
    Date

    On 2019/7/23 下午6:42, Michael S. Tsirkin wrote:
    > On Tue, Jul 23, 2019 at 04:42:19PM +0800, Jason Wang wrote:
    >>> So how about this: do exactly what you propose but as a 2 patch series:
    >>> start with the slow safe patch, and add then return uaddr optimizations
    >>> on top. We can then more easily reason about whether they are safe.
    >>
    >> If you stick, I can do this.
    > So I definitely don't insist but I'd like us to get back to where
    > we know existing code is very safe (if not super fast) and
    > optimizing from there. Bugs happen but I'd like to see a bisect
    > giving us "oh it's because of XYZ optimization" and not the
    > general "it's somewhere within this driver" that we are getting
    > now.


    Syzbot has bisected to the commit of metadata acceleration in fact :)


    >
    > Maybe the way to do this is to revert for this release cycle
    > and target the next one. What do you think?


    I would try to fix the issues consider packed virtqueue which may use
    this for a good performance number. But if you insist, I'm ok to revert.
    Or maybe introduce a config option to disable it by default (almost all
    optimized could be ruled out).

    Thanks

    \
     
     \ /
      Last update: 2019-07-23 15:38    [W:4.464 / U:0.168 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site