• Dan Duval's avatar
    audit: efficiency fix 2: request exclusive wait since all need same resource · 7ecf69bf
    Dan Duval authored
    These and similar errors were seen on a patched 3.8 kernel when the
    audit subsystem was overrun during boot:
    
      udevd[876]: worker [887] unexpectedly returned with status 0x0100
      udevd[876]: worker [887] failed while handling
    '/devices/pci0000:00/0000:00:03.0/0000:40:00.0'
      udevd[876]: worker [880] unexpectedly returned with status 0x0100
      udevd[876]: worker [880] failed while handling
    '/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1'
    
      udevadm settle - timeout of 180 seconds reached, the event queue
    contains:
        /sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1/event1 (3995)
        /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/INT3F0D:00 (4034)
    
      audit: audit_backlog=258 > audit_backlog_limit=256
      audit: audit_lost=1 audit_rate_limit=0 audit_backlog_limit=256
    
    The change below increases the efficiency of the audit code and prevents it
    from being overrun:
    
    Use add_wait_queue_exclusive() in wait_for_auditd() to put the
    thread on the wait queue.  When kauditd dequeues an skb, all
    of the waiting threads are waiting for the same resource, but
    only one is going to get it, so there's no need to wake up
    more than one waiter.
    
    See: https://lkml.org/lkml/2013/9/2/479Signed-off-by: default avatarDan Duval <dan.duval@oracle.com>
    Signed-off-by: default avatarChuck Anderson <chuck.anderson@oracle.com>
    Signed-off-by: default avatarRichard Guy Briggs <rgb@redhat.com>
    Signed-off-by: default avatarEric Paris <eparis@redhat.com>
    7ecf69bf
audit.c 49.1 KB