Commit 1c1377d7 authored by Breno Leitao's avatar Breno Leitao Committed by David S. Miller
Browse files

netconsole: consolidate send buffers into netconsole_target struct 



Move the static buffers from send_msg_no_fragmentation() and
send_msg_fragmented() into the netconsole_target structure. This
simplifies the code by:
- Eliminating redundant static buffers
- Centralizing buffer management in the target structure
- Reducing memory usage by 1KB (one buffer instead of two)

The buffer in netconsole_target is protected by target_list_lock,
maintaining the same synchronization semantics as the original code.

Suggested-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent acdefab0

drivers/net/netconsole.c

+16 −14
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ struct netconsole_target_stats { 
 *		remote_ip	(read-write)

 *		local_mac	(read-only)

 *		remote_mac	(read-write)

 * @buf:	The buffer used to send the full msg to the network stack

 */

struct netconsole_target {

	struct list_head	list;
@@ -137,6 +138,8 @@ struct netconsole_target { 
	bool			extended;

	bool			release;

	struct netpoll		np;

	/* protected by target_list_lock */

	char			buf[MAX_PRINT_CHUNK];

};



#ifdef	CONFIG_NETCONSOLE_DYNAMIC
@@ -1117,7 +1120,6 @@ static void send_msg_no_fragmentation(struct netconsole_target *nt, 
				      int msg_len,

				      int release_len)

{

	static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */

	const char *userdata = NULL;

	const char *release;
@@ -1128,18 +1130,18 @@ static void send_msg_no_fragmentation(struct netconsole_target *nt, 
	if (release_len) {

		release = init_utsname()->release;



		scnprintf(buf, MAX_PRINT_CHUNK, "%s,%s", release, msg);

		scnprintf(nt->buf, MAX_PRINT_CHUNK, "%s,%s", release, msg);

		msg_len += release_len;

	} else {

		memcpy(buf, msg, msg_len);

		memcpy(nt->buf, msg, msg_len);

	}



	if (userdata)

		msg_len += scnprintf(&buf[msg_len],

		msg_len += scnprintf(&nt->buf[msg_len],

				     MAX_PRINT_CHUNK - msg_len,

				     "%s", userdata);



	send_udp(nt, buf, msg_len);

	send_udp(nt, nt->buf, msg_len);

}



static void append_release(char *buf)
@@ -1150,7 +1152,7 @@ static void append_release(char *buf) 
	scnprintf(buf, MAX_PRINT_CHUNK, "%s,", release);

}



static void send_fragmented_body(struct netconsole_target *nt, char *buf,

static void send_fragmented_body(struct netconsole_target *nt,

				 const char *msgbody, int header_len,

				 int msgbody_len)

{
@@ -1181,7 +1183,7 @@ static void send_fragmented_body(struct netconsole_target *nt, char *buf, 
		int this_offset = 0;

		int this_chunk = 0;



		this_header += scnprintf(buf + this_header,

		this_header += scnprintf(nt->buf + this_header,

					 MAX_PRINT_CHUNK - this_header,

					 ",ncfrag=%d/%d;", offset,

					 body_len);
@@ -1192,7 +1194,8 @@ static void send_fragmented_body(struct netconsole_target *nt, char *buf, 
					 MAX_PRINT_CHUNK - this_header);

			if (WARN_ON_ONCE(this_chunk <= 0))

				return;

			memcpy(buf + this_header, msgbody + offset, this_chunk);

			memcpy(nt->buf + this_header, msgbody + offset,

			       this_chunk);

			this_offset += this_chunk;

		}
@@ -1226,13 +1229,13 @@ static void send_fragmented_body(struct netconsole_target *nt, char *buf, 
				 */

				return;



			memcpy(buf + this_header + this_offset,

			memcpy(nt->buf + this_header + this_offset,

			       userdata + sent_userdata,

			       this_chunk);

			this_offset += this_chunk;

		}



		send_udp(nt, buf, this_header + this_offset);

		send_udp(nt, nt->buf, this_header + this_offset);

		offset += this_offset;

	}

}
@@ -1242,7 +1245,6 @@ static void send_msg_fragmented(struct netconsole_target *nt, 
				int msg_len,

				int release_len)

{

	static char buf[MAX_PRINT_CHUNK]; /* protected by target_list_lock */

	int header_len, msgbody_len;

	const char *msgbody;
@@ -1260,16 +1262,16 @@ static void send_msg_fragmented(struct netconsole_target *nt, 
	 * "ncfrag=<byte-offset>/<total-bytes>"

	 */

	if (release_len)

		append_release(buf);

		append_release(nt->buf);



	/* Copy the header into the buffer */

	memcpy(buf + release_len, msg, header_len);

	memcpy(nt->buf + release_len, msg, header_len);

	header_len += release_len;



	/* for now on, the header will be persisted, and the msgbody

	 * will be replaced

	 */

	send_fragmented_body(nt, buf, msgbody, header_len, msgbody_len);

	send_fragmented_body(nt, msgbody, header_len, msgbody_len);

}



/**