• Robin Getz's avatar
    Blackfin: optimize strncpy a bit · 648eee52
    Robin Getz authored
    Add a little strncpy optimization which can easily cut boot time by 20%.
    
    When the kernel is booting with initramfs, it builds up the filesystem
    from a cpio archive by calling strncpy_from_user() via fs/namei.c's
    do_getname() on every file in the archive (which can be lots) with a
    length of PATH_MAX (1024).  This causes the dest of the strncpy to be
    padded with many NUL bytes.
    
    This optimization mostly causes these NUL bytes to be padded with a call
    to memset() which is already optimized for filling memory quickly, but
    the hardware loop helps a little bit as well.
    
    Boot time measured with 'loglevel=0' so UART speed doesn't get in the way.
    Signed-off-by: default avatarRobin Getz <robin.getz@analog.com>
    Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
    648eee52
memset.S 1.8 KB