lkml.org 
[lkml]   [2010]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH -mm 3/3] proc: make task_sig() lockless
    Date
    > Yes, /proc/pid/status can report the intermediate state, I even sent
    > the updated changelog to document this.
    >
    > But if you are not sure this is OK, I am worried. Do you think we should
    > drop this patch? If yes, I won't argue.

    I'm not dead-set against it, but I am hesitant. My inclination is not to
    remove any previous userland atomicity guarantees with regard to observable
    signal state in any form. At least, don't do that in part of a whole
    cleanup flurry where it is intermixed with lots of changes that really are
    pure cleanup with absolutely no userland-observable change. If it really
    helps to fragment what was atomic before, then we can consider it. But
    let's not be in a hurry.

    David mentioned that users who do multiple reads due to using tiny buffers
    already don't get atomic sampling. That is certainly true but I don't
    think it's relevant. It is completely reliable that you can easily
    allocate a buffer big enough to get all the Sig* fields on the first read,
    and any user program that might care about the coherence of the data,
    by definition, is already doing that.


    Thanks,
    Roland


    \
     
     \ /
      Last update: 2010-04-13 08:33    [W:3.856 / U:0.572 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site