diff options
| author | Mandeep Singh Baines <msb@chromium.org> | 2011-08-05 18:46:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-08-06 11:26:52 -0700 |
| commit | 1eb19a12bd2214cdcad5273d472b062a4ba97fa1 (patch) | |
| tree | a88b76f31a4ea5e3631581be249759fcf4b05a08 /include | |
| parent | de96355c111679dd6e2c5c73e25e814c72510c58 (diff) | |
lib/sha1: use the git implementation of SHA-1
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: Mandeep 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: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cryptohash.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/cryptohash.h b/include/linux/cryptohash.h index ec78a4bbe1d5..f9452185b019 100644 --- a/include/linux/cryptohash.h +++ b/include/linux/cryptohash.h @@ -3,7 +3,7 @@ #define SHA_DIGEST_WORDS 5 #define SHA_MESSAGE_BYTES (512 /*bits*/ / 8) -#define SHA_WORKSPACE_WORDS 80 +#define SHA_WORKSPACE_WORDS 16 void sha_init(__u32 *buf); void sha_transform(__u32 *digest, const char *data, __u32 *W); |