From 464fa06e9adbadc0c93fa5866d8fa4f55d69c2eb Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Fri, 17 Mar 2023 16:09:14 +0100 Subject: [PATCH] MINOR: mux-h2: set CO_SFL_MSG_MORE when sending multiple buffers Traces show that sendto() rarely has MSG_MORE on H2 despite sending multiple buffers. The reason is that the loop iterating over the buffer ring doesn't have this info and doesn't pass it down. But now we know how many buffers are left to be sent, so we know whether or not the current buffer is the last one. As such we can set this flag for all buffers but the last one. --- src/mux_h2.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/mux_h2.c b/src/mux_h2.c index f5fa27f48..c2c9b2142 100644 --- a/src/mux_h2.c +++ b/src/mux_h2.c @@ -3798,6 +3798,7 @@ static int h2_send(struct h2c *h2c) unsigned int flags = 0; unsigned int released = 0; struct buffer *buf; + uint to_send; /* fill as much as we can into the current buffer */ while (((h2c->flags & (H2_CF_MUX_MFULL|H2_CF_MUX_MALLOC)) == 0) && !done) @@ -3813,7 +3814,8 @@ static int h2_send(struct h2c *h2c) if (h2c->flags & (H2_CF_MUX_MFULL | H2_CF_DEM_MROOM)) flags |= CO_SFL_MSG_MORE; - if (!br_single(h2c->mbuf)) { + to_send = br_count(h2c->mbuf); + if (to_send > 1) { /* usually we want to emit small TLS records to speed * up the decoding on the client. That's what is being * done by default. However if there is more than one @@ -3825,12 +3827,14 @@ static int h2_send(struct h2c *h2c) for (buf = br_head(h2c->mbuf); b_size(buf); buf = br_del_head(h2c->mbuf)) { if (b_data(buf)) { - int ret = conn->xprt->snd_buf(conn, conn->xprt_ctx, buf, b_data(buf), flags); + int ret = conn->xprt->snd_buf(conn, conn->xprt_ctx, buf, b_data(buf), + flags | (to_send > 1 ? CO_SFL_MSG_MORE : 0)); if (!ret) { done = 1; break; } sent = 1; + to_send--; TRACE_DATA("sent data", H2_EV_H2C_SEND, h2c->conn, 0, buf, (void*)(long)ret); b_del(buf, ret); if (b_data(buf)) {