Decrease OTA package verification times further.
Timing from Nexus 5X:
89 MiB OTA update package: 1.4 s -> 0.6 s (decreased by 57%)
1196 MiB OTA update package: 8.0 s -> 7.5 s (decreased by 6%)
Bug: http://b/28135231
Change-Id: Id91f2ad15df2bffb9f8a4b4ec5a57657a02847ec
diff --git a/verifier.cpp b/verifier.cpp
index 4004b02..f5299b4 100644
--- a/verifier.cpp
+++ b/verifier.cpp
@@ -206,10 +206,10 @@
double frac = -1.0;
size_t so_far = 0;
while (so_far < signed_len) {
- // On a Nexus 9, experiment didn't show any performance improvement with
- // larger sizes past 1MiB, and they reduce the granularity of the progress
- // bar. http://b/28135231.
- size_t size = std::min(signed_len - so_far, 1 * MiB);
+ // On a Nexus 5X, experiment showed 16MiB beat 1MiB by 6% faster for a
+ // 1196MiB full OTA and 60% for an 89MiB incremental OTA.
+ // http://b/28135231.
+ size_t size = std::min(signed_len - so_far, 16 * MiB);
if (need_sha1) SHA1_Update(&sha1_ctx, addr + so_far, size);
if (need_sha256) SHA256_Update(&sha256_ctx, addr + so_far, size);