# HG changeset patch
# User Lars Ellenberg <[email protected]>
# Date 1285685263 -7200
# Node ID beedb189b8a9c47c793f898755d0e301aacce4d4
# Parent 94f4ee6025502c7ef710775d458ef766c51ad6db
Medium: adjust socket buffers when adjusting ipc queue length
If a channel adjusts its ipc queue length,
it is probably a good idea to also change
the socket buffers on the system level.
The scaling qlen -> buffsize is somewhat arbitrary.
diff -r 94f4ee602550 -r beedb189b8a9 lib/clplumbing/ipcsocket.c
--- a/lib/clplumbing/ipcsocket.c Tue Sep 28 16:01:48 2010 +0200
+++ b/lib/clplumbing/ipcsocket.c Tue Sep 28 16:47:43 2010 +0200
@@ -1715,6 +1715,36 @@
return socket_get_recv_fd(ch);
}
+static void
+socket_adjust_buf(struct IPC_CHANNEL *ch, int optname, unsigned q_len)
+{
+ const char *direction = optname == SO_SNDBUF ? "snd" : "rcv";
+ int fd = socket_get_send_fd(ch);
+ unsigned byte;
+
+ /* Arbitrary scaling.
+ * DEFAULT_MAX_QLEN is 64, default socket buf is often 64k to 128k,
+ * at least on those linux I checked.
+ * Keep that ratio, and allow for some overhead. */
+ if (qlen == 0)
+ /* client does not want anything,
+ * reduce system buffers as well */
+ byte = 4096;
+ else if (q_len < 512)
+ byte = (32 + q_len) * 1024;
+ else
+ byte = q_len * 1024;
+
+ if (0 == setsockopt(fd, SOL_SOCKET, optname, &byte, sizeof(byte))) {
+ cl_log(LOG_DEBUG, "adjusted %sbuf size to %u", direction,
bytes);
+ } else {
+ /* If this fails, you may need to adjust net.core.rmem_max,
+ * ...wmem_max, or equivalent */
+ cl_log(LOG_DEBUG, "adjust %sbuf size to %u failed: %s",
+ direction, byte, strerror(errno));
+ }
+}
+
static int
socket_set_send_qlen (struct IPC_CHANNEL* ch, int q_len)
{
@@ -1722,9 +1752,9 @@
if (ch->send_queue == NULL) {
return IPC_FAIL;
}
+ socket_adjust_buf(ch, SO_SNDBUF, q_len);
ch->send_queue->max_qlen = q_len;
- return IPC_OK;
-
+ return IPC_OK;
}
static int
@@ -1734,7 +1764,7 @@
if (ch->recv_queue == NULL) {
return IPC_FAIL;
}
-
+ socket_adjust_buf(ch, SO_RCVBUF, q_len);
ch->recv_queue->max_qlen = q_len;
return IPC_OK;
}
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