mbufs and mbuf clusters are now backed by large pools. Because of this

we can relax the oversubscribe limit of socketbuffers a fair bit.
Instead of maxing out as sb_max * 1.125 or 2 * sb_hiwat the maximum is
increased to 8 * sb_hiwat -- which seems to be a good compromise between
memory waste and better socket buffer usage.
OK deraadt@

diff --git a/sys/kern/uipc_socket2.c b/sys/kern/uipc_socket2.c
index a7c6ba1..d795315 100644 (file)
--- a/sys/kern/uipc_socket2.c
+++ b/sys/kern/uipc_socket2.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uipc_socket2.c,v 1.89 2017/12/30 20:47:00 guenther Exp $      */
+/*     $OpenBSD: uipc_socket2.c,v 1.90 2018/02/10 06:00:06 claudio Exp $       */
 /*     $NetBSD: uipc_socket2.c,v 1.11 1996/02/04 02:17:55 christos Exp $       */
 
 /*
@@ -464,8 +464,7 @@ sbreserve(struct socket *so, struct sockbuf *sb, u_long cc)
        if (cc == 0 || cc > sb_max)
                return (1);
        sb->sb_hiwat = cc;
-       sb->sb_mbmax = max(3 * MAXMCLBYTES,
-           min(cc * 2, sb_max + (sb_max / MCLBYTES) * MSIZE));
+       sb->sb_mbmax = max(3 * MAXMCLBYTES, cc * 8);
        if (sb->sb_lowat > sb->sb_hiwat)
                sb->sb_lowat = sb->sb_hiwat;
        return (0);