1. 06 Aug, 2011 1 commit
    • Mandeep Singh Baines's avatar
      lib/sha1: use the git implementation of SHA-1 · 1eb19a12
      Mandeep Singh Baines authored
      For ChromiumOS, we use SHA-1 to verify the integrity of the root
      filesystem.  The speed of the kernel sha-1 implementation has a major
      impact on our boot performance.
      
      To improve boot performance, we investigated using the heavily optimized
      sha-1 implementation used in git.  With the git sha-1 implementation, we
      see a 11.7% improvement in boot time.
      
      10 reboots, remove slowest/fastest.
      
      Before:
      
        Mean: 6.58 seconds Stdev: 0.14
      
      After (with git sha-1, this patch):
      
        Mean: 5.89 seconds Stdev: 0.07
      
      The other cool thing about the git SHA-1 implementation is that it only
      needs 64 bytes of stack for the workspace while the original kernel
      implementation needed 320 bytes.
      Signed-off-by: default avatarMandeep Singh Baines <msb@chromium.org>
      Cc: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
      Cc: Nicolas Pitre <nico@cam.org>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: linux-crypto@vger.kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1eb19a12
  2. 05 Aug, 2011 19 commits
  3. 04 Aug, 2011 20 commits