Thanks very much that's fine (and sorry for us not acting on it earlier). Kind regards, Roksana -----Original Message----- From: Gerrit Renker [mailto:gerrit@xxxxxxxxxxxxxx] Sent: Wednesday, 14 May 2008 7:16 PM To: Babil Cc: Roksana Boreli; dccp@xxxxxxxxxxxxxxx; Emmanuel Lochin (External) Subject: [CCID-4] [Patch 1/1]: Bug fix - no header penalty during slow-start I haven't heard back so I put the following patch corresponding to your description at the top of the ccid4 subtree. I can easily replace it if people wanted this differently. -------------------------> Patch -------------------------> <------------------------------------------ [CCID4]: No header penalty in slow-start Bug fix reported by Roksana Boreli on 12/5/2008: header penalty was incorrectly applied during slow-start. For packet sizes s this meant that the slow-start degenerated into an exponential decrease, due to X_0 = RFC3390 initial rate X_i+1 = 2 / (1 + 36/s) * X_i ; for i >= 1 When s < 36, the multiplicative factor is less than 1, causing a reduction of X each time during slow start. Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> --- net/dccp/ccids/ccid4.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) --- a/net/dccp/ccids/ccid4.c +++ b/net/dccp/ccids/ccid4.c @@ -93,17 +93,6 @@ static void ccid4_update_send_interval(s } /** - * ccid4_hc_tx_x_header_penalty - Update allowed sending rate X - * @hctx: half-connection to adjust - * This function adjusts sending rate according to [TFRC-SP, Section 5] - */ -static inline void ccid4_hc_tx_x_header_penalty(struct tfrc_hc_tx_sock *hctx) -{ - hctx->x *= hctx->s; - do_div(hctx->x, (hctx->s + CCID4HCTX_H)); -} - -/** * ccid4_hc_tx_update_x - Update allowed sending rate X * @stamp: most recent time if available - can be left NULL. * This function tracks draft rfc3448bis, check there for latest details. @@ -136,14 +125,18 @@ static void ccid4_hc_tx_update_x(struct hctx->x = min(((u64)hctx->x_calc) << 6, min_rate); low_thresh /= TFRC_T_MBI; - ccid4_hc_tx_x_header_penalty(hctx); + /* + * CCID-4 Header Penalty: + * Adjust sending rate according to [TFRC-SP, Section 5] + */ + hctx->x *= hctx->s; + do_div(hctx->x, hctx->s + CCID4HCTX_H); } else if (ktime_us_delta(now, hctx->t_ld) - (s64)hctx->rtt >= 0) { hctx->x = min(2 * old_x, min_rate); low_thresh = scaled_div(low_thresh, hctx->rtt); hctx->t_ld = now; - ccid4_hc_tx_x_header_penalty(hctx); } if (hctx->x != old_x) { -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
