Merge pull request #8570 from qlyoung/revert-ringbuf-readv

Revert "bgpd: improve socket read performance"

bgpd/bgp_io.c

@@ -462,10 +462,13 @@ done : {
  */
 static uint16_t bgp_read(struct peer *peer, int *code_p)
 {
+	size_t readsize; // how many bytes we want to read
 	ssize_t nbytes;  // how many bytes we actually read
 	uint16_t status = 0;
 
-	nbytes = ringbuf_read(peer->ibuf_work, peer->fd);
+	readsize =
+		MIN(ringbuf_space(peer->ibuf_work), sizeof(peer->ibuf_scratch));
+	nbytes = read(peer->fd, peer->ibuf_scratch, readsize);
 
 	/* EAGAIN or EWOULDBLOCK; come back later */
 	if (nbytes < 0 && ERRNO_IO_RETRY(errno)) {
@@ -493,6 +496,9 @@ static uint16_t bgp_read(struct peer *peer, int *code_p)
 			*code_p = TCP_connection_closed;
 
 		SET_FLAG(status, BGP_IO_FATAL_ERR);
+	} else {
+		assert(ringbuf_put(peer->ibuf_work, peer->ibuf_scratch, nbytes)
+		       == (size_t)nbytes);
 	}
 
 	return status;

bgpd/bgpd.h

@@ -44,6 +44,7 @@
 #include "bgp_addpath_types.h"
 #include "bgp_nexthop.h"
 #include "bgp_damp.h"
+#include "bgp_io.h"
 
 #include "lib/bfd.h"
 
@@ -1047,6 +1048,9 @@ struct peer {
 	struct stream_fifo *ibuf; // packets waiting to be processed
 	struct stream_fifo *obuf; // packets waiting to be written
 
+	/* used as a block to deposit raw wire data to */
+	uint8_t ibuf_scratch[BGP_MAX_EXTENDED_MESSAGE_PACKET_SIZE
+			     * BGP_READ_PACKET_MAX];
 	struct ringbuf *ibuf_work; // WiP buffer used by bgp_read() only
 	struct stream *obuf_work;  // WiP buffer used to construct packets
 

lib/ringbuf.c

@@ -131,38 +131,3 @@ void ringbuf_wipe(struct ringbuf *buf)
 	memset(buf->data, 0x00, buf->size);
 	ringbuf_reset(buf);
 }
-
-ssize_t ringbuf_read(struct ringbuf *buf, int sock)
-{
-	size_t to_read = ringbuf_space(buf);
-	size_t bytes_to_end = buf->size - buf->end;
-	ssize_t bytes_read;
-	struct iovec iov[2] = {};
-
-	/* Calculate amount of read blocks. */
-	if (to_read > bytes_to_end) {
-		iov[0].iov_base = buf->data + buf->end;
-		iov[0].iov_len = bytes_to_end;
-		iov[1].iov_base = buf->data;
-		iov[1].iov_len = to_read - bytes_to_end;
-	} else {
-		iov[0].iov_base = buf->data + buf->end;
-		iov[0].iov_len = to_read;
-	}
-
-	/* Do the system call. */
-	bytes_read = readv(sock, iov, 2);
-	if (bytes_read <= 0)
-		return bytes_read;
-
-	/* Calculate the new end. */
-	if ((size_t)bytes_read > bytes_to_end)
-		buf->end = bytes_read - bytes_to_end;
-	else
-		buf->end += bytes_read;
-
-	/* Set emptiness state. */
-	buf->empty = (buf->start == buf->end) && (buf->empty && !bytes_read);
-
-	return bytes_read;
-}

lib/ringbuf.h

@@ -126,17 +126,6 @@ void ringbuf_reset(struct ringbuf *buf);
  */
 void ringbuf_wipe(struct ringbuf *buf);
 
-/**
- * Perform a socket/file `read()` in to the ring buffer.
- *
- * \param buf the ring buffer pointer.
- * \param sock the file descriptor.
- * \returns the number of bytes read, `0` on connection close or `-1` with
- *          `errno` pointing the error (see `readv()` man page for more
- *          information.)
- */
-ssize_t ringbuf_read(struct ringbuf *buf, int sock);
-
 #ifdef __cplusplus
 }
 #endif