lkml.org 
[lkml]   [2010]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Subjectkmem_cache_destroy() badness with SLUB
    From
    Date
    Hi folks !

    Internally, I'm hitting a little "nit"...

    sysfs_slab_add() has this check:

    if (slab_state < SYSFS)
    /* Defer until later */
    return 0;

    But sysfs_slab_remove() doesn't.

    So if the slab is created -and- destroyed at, for example, arch_initcall
    time, then we hit a WARN in the kobject code, trying to dispose of a
    non-existing kobject.

    Now, at first sight, just adding the same test to sysfs_slab_remove()
    would do the job... but it all seems very racy to me.

    I don't understand in fact how this slab_state deals with races at all.

    What prevents us from hitting slab_sysfs_init() at the same time as
    another CPU deos sysfs_slab_add() ? How do that deal with collisions
    trying to register the same kobject twice ? Similar race with remove...

    Shouldn't we have a mutex around those guys ?

    Cheers,
    Ben.




    \
     
     \ /
      Last update: 2010-06-28 03:51    [W:0.018 / U:29.572 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site