MINOR: quic: Stop using 1024th of a second.

Use milliseconds in place of 1024th of a second.

Should be backported as far as 2.6.

diff --git a/src/quic_cc_cubic.c b/src/quic_cc_cubic.c
index 38557e044f4080e1828944c22eae9cefc860c5da..a0f85466f84b11d6292d5a58825e0cf40fc0d3f7 100644 (file)
--- a/src/quic_cc_cubic.c
+++ b/src/quic_cc_cubic.c
@@ -46,9 +46,6 @@
 /* The scaled value of 1 */
 #define CUBIC_ONE_SCALED  (1 << CUBIC_SCALE_FACTOR_SHIFT)
 
-/* The left bit shifting to apply to convert milliseconds to seconds. */
-#define TIME_SCALE_FACTOR_SHIFT      10
-
 /* The maximum time value which may be cubed and multiplied by CUBIC_C_SCALED */
 #define CUBIC_TIME_LIMIT    355535ULL  /* ms */
 
@@ -242,10 +239,10 @@ static inline void quic_cubic_update(struct quic_cc *cc, uint32_t acked)
                else {
                        /* K value computing (in seconds):
                         * K = cubic_root((W_max - cwnd_epoch)/C) (Figure 2)
-                        * Note that K is stored in 1024th of a second.
+                        * Note that K is stored in milliseconds.
                         */
                        c->K = cubic_root((c->last_w_max - path->cwnd) *
-                                         ((CUBIC_ONE_SCALED - CUBIC_BETA_SCALED) << TIME_SCALE_FACTOR_SHIFT) / (CUBIC_C_SCALED * path->mtu));
+                                         (CUBIC_ONE_SCALED - CUBIC_BETA_SCALED) * 1000 / (CUBIC_C_SCALED * path->mtu));
                        c->W_target = c->last_w_max;
                }
 
@@ -274,9 +271,9 @@ static inline void quic_cubic_update(struct quic_cc *cc, uint32_t acked)
 
        /* Compute W_cubic_t at t time. */
        W_cubic_t = CUBIC_C_SCALED * path->mtu;
-       W_cubic_t = (W_cubic_t * t) >> TIME_SCALE_FACTOR_SHIFT;
-       W_cubic_t = (W_cubic_t * t) >> TIME_SCALE_FACTOR_SHIFT;
-       W_cubic_t = (W_cubic_t * t) >> TIME_SCALE_FACTOR_SHIFT;
+       W_cubic_t = (W_cubic_t * t) / 1000;
+       W_cubic_t = (W_cubic_t * t) / 1000;
+       W_cubic_t = (W_cubic_t * t) / 1000;
        W_cubic_t >>= CUBIC_SCALE_FACTOR_SHIFT;
        if (elapsed_time < c->K)
                target = c->W_target - W_cubic_t;