[lkml]   [2008]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 0/2] lockdep vs recursive read locks
    On Wed, 12 Mar 2008, Peter Zijlstra wrote:
    > We seemed to have some lockdep trouble wrt recursive read locks. Today Gautham
    > asked me some specific questions about it, which led to these patches.
    > IIRC Hugh ran into something similar a while back. This hopefully fixes it.

    Hmm, I don't remember that myself: can you jog my memory?

    What I do remember is that when I fixed madvise(MADV_REMOVE i.e. holepunch)
    not to hold mmap_sem (at that time down_write but today down_read, though
    would still be bad) across vmtruncate_range which takes i_mutex (contrast
    writing from an unfaulted area that takes i_mutex then down_read mmap_sem),
    Ingo asked me offline if lockdep caught that and it didn't. Just tried
    again now, with your patches applied, and madvise_remove restored to its
    old misbehaviour, and it looks like lockdep still doesn't catch it
    (but suspect me of pilot error if you find otherwise).


     \ /
      Last update: 2008-03-13 12:29    [W:0.024 / U:42.572 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site