From: Christopher Faulet <cfaulet@haproxy.com>
Date: Mon, 4 Dec 2023 14:18:49 +0000 (+0100)
Subject: MINOR: mux-h2: Add global option to enable/disable zero-copy forwarding
X-Git-Tag: v2.9.0~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6da0429e750d22daab2fd0ea66f8bd810cdfa40e;p=thirdparty%2Fhaproxy.git

MINOR: mux-h2: Add global option to enable/disable zero-copy forwarding

tune.h2.zero-copy-fwd-send can now be used to enable or disable the
zero-copy fast-forwarding for the H2 mux only, for sends. For now, there is
no option to disable it for receives because it is not supported yet.

It is enabled ('on') by default.
---

diff --git a/doc/configuration.txt b/doc/configuration.txt
index cf794fa039..bcdaae1fa4 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1191,6 +1191,7 @@ The following keywords are supported in the "global" section :
    - tune.h2.initial-window-size
    - tune.h2.max-concurrent-streams
    - tune.h2.max-frame-size
+   - tune.h2.zero-copy-fwd-send
    - tune.http.cookielen
    - tune.http.logurilen
    - tune.http.maxhdr
@@ -2925,7 +2926,8 @@ tune.disable-zero-copy-forwarding
   it also disable any kernel tcp splicing.
 
   See also: tune.pt.zero-copy-forwarding,
-            tune.h1.zero-copy-fwd-recv, tune.h1.zero-copy-fwd-send
+            tune.h1.zero-copy-fwd-recv, tune.h1.zero-copy-fwd-send,
+            tune.h2.zero-copy-fwd-send
 
 tune.events.max-events-at-once <number>
   Sets the number of events that may be processed at once by an asynchronous
@@ -3052,6 +3054,12 @@ tune.h2.max-frame-size <number>
   large frame sizes might have performance impact or cause some peers to
   misbehave. It is highly recommended not to change this value.
 
+tune.h2.zero-copy-fwd-send { on | off }
+  Enables ('on') of disabled ('off') the zero-copy sends of data for the H2
+  multiplexer. It is enabled by default.
+
+  See also: tune.disable-zero-copy-forwarding
+
 tune.http.cookielen <number>
   Sets the maximum length of captured cookies. This is the maximum value that
   the "capture cookie xxx len yyy" will be allowed to take, and any upper value
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 641b5dafc4..ad7c59f998 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -6935,6 +6935,11 @@ static size_t h2_nego_ff(struct stconn *sc, struct buffer *input, size_t count,
 
 	TRACE_ENTER(H2_EV_H2S_SEND|H2_EV_STRM_SEND, h2s->h2c->conn, h2s);
 
+	if (global.tune.no_zero_copy_fwd & NO_ZERO_COPY_FWD_H2_SND) {
+		h2s->sd->iobuf.flags |= IOBUF_FL_NO_FF;
+		goto end;
+	}
+
 	/* If we were not just woken because we wanted to send but couldn't,
 	 * and there's somebody else that is waiting to send, do nothing,
 	 * we will subscribe later and be put at the end of the list
@@ -7439,6 +7444,25 @@ static int h2_parse_max_frame_size(char **args, int section_type, struct proxy *
 }
 
 
+/* config parser for global "tune.h2.zero-copy-fwd-send" */
+static int h2_parse_zero_copy_fwd_snd(char **args, int section_type, struct proxy *curpx,
+					  const struct proxy *defpx, const char *file, int line,
+					  char **err)
+{
+	if (too_many_args(1, args, err, NULL))
+		return -1;
+
+	if (strcmp(args[1], "on") == 0)
+		global.tune.no_zero_copy_fwd &= ~NO_ZERO_COPY_FWD_H2_SND;
+	else if (strcmp(args[1], "off") == 0)
+		global.tune.no_zero_copy_fwd |= NO_ZERO_COPY_FWD_H2_SND;
+	else {
+		memprintf(err, "'%s' expects 'on' or 'off'.", args[0]);
+		return -1;
+	}
+	return 0;
+}
+
 /****************************************/
 /* MUX initialization and instantiation */
 /***************************************/
@@ -7486,6 +7510,7 @@ static struct cfg_kw_list cfg_kws = {ILH, {
 	{ CFG_GLOBAL, "tune.h2.initial-window-size",    h2_parse_initial_window_size    },
 	{ CFG_GLOBAL, "tune.h2.max-concurrent-streams", h2_parse_max_concurrent_streams },
 	{ CFG_GLOBAL, "tune.h2.max-frame-size",         h2_parse_max_frame_size         },
+	{ CFG_GLOBAL, "tune.h2.zero-copy-fwd-send",     h2_parse_zero_copy_fwd_snd },
 	{ 0, NULL, NULL }
 }};