lkml.org 
[lkml]   [2012]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch] mm, hugetlb: add thread name and pid to SHM_HUGETLB mlock rlimit warning
    On Tue, 6 Mar 2012 18:26:11 -0800 (PST)
    David Rientjes <rientjes@google.com> wrote:

    > Add the thread name and pid of the application that is allocating shm
    > segments with MAP_HUGETLB without being a part of
    > /proc/sys/vm/hugetlb_shm_group or having CAP_IPC_LOCK.
    >
    > This identifies the application so it may be fixed by avoiding using the
    > deprecated exception (see Documentation/feature-removal-schedule.txt).
    >
    > ...
    >
    > --- a/fs/hugetlbfs/inode.c
    > +++ b/fs/hugetlbfs/inode.c
    > @@ -946,7 +946,11 @@ struct file *hugetlb_file_setup(const char *name, size_t size,
    > if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
    > *user = current_user();
    > if (user_shm_lock(size, *user)) {
    > - printk_once(KERN_WARNING "Using mlock ulimits for SHM_HUGETLB is deprecated\n");
    > + task_lock(current);
    > + printk_once(KERN_WARNING
    > + "%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
    > + current->comm, current->pid);
    > + task_unlock(current);

    I assume the task_lock() is there to protect current->comm. If so, it
    is unneeded - we're protecting against prctl(PR_SET_NAME), and
    PR_SET_NAME only operates on current, and we know this task isn't
    currently running PR_SET_NAME.

    If there's a way for another task to alter this task's ->comm then we
    _do_ need locking. But there isn't a way, I hope.



    \
     
     \ /
      Last update: 2012-03-08 21:05    [W:0.019 / U:62.476 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site