• Arjan van de Ven's avatar
    kobject: don't block for each kobject_uevent · f520360d
    Arjan van de Ven authored
    Right now, the kobject_uevent code blocks for each uevent that's being
    generated, due to using (for hystoric reasons) UHM_WAIT_EXEC as flag to
    call_usermode_helper().  Specifically, the effect is that each uevent
    that is being sent causes the code to wake up keventd, then block until
    keventd has processed the work. Needless to say, this happens many times
    during the system boot.
    
    This patches changes that to UHN_NO_WAIT (brilliant name for a constant
    btw) so that we only schedule the work to fire the uevent message, but
    do not wait for keventd to process the work.
    
    This removes one of the bottlenecks during boot; each one of them is
    only a small effect, but the sum of them does add up.
    
    [Note, distros that need this are broken, they should be setting
    CONFIG_UEVENT_HELPER_PATH to "", that way this code path will never be
    excuted at all -- gregkh]
    Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    f520360d
kobject_uevent.c 8.24 KB