lib/PublicInbox/CmdIPC4.pm | 11 ++++++++++-
 lib/PublicInbox/Spawn.pm   | 27 +++++++++++++++++++++++----

diff --git a/lib/PublicInbox/CmdIPC4.pm b/lib/PublicInbox/CmdIPC4.pm
index 74dbf8a12ee4a8090a16d75a8ddbcaee6271cf3b..c3a7f56ec7e3f356243d270447402aa3217c499a 100644
--- a/lib/PublicInbox/CmdIPC4.pm
+++ b/lib/PublicInbox/CmdIPC4.pm
@@ -17,7 +17,16 @@ *send_cmd4 = sub ($$$$) { # (sock, fds, buf, flags) = @_;
 	my ($sock, $fds, undef, $flags) = @_;
 	my $mh = Socket::MsgHdr->new(buf => $_[2]);
 	$mh->cmsghdr(SOL_SOCKET, SCM_RIGHTS, pack('i' x scalar(@$fds), @$fds));
-	Socket::MsgHdr::sendmsg($sock, $mh, $flags);
+	my $s;
+	my $try = 0;
+	do {
+		$s = Socket::MsgHdr::sendmsg($sock, $mh, $flags);
+	} while (!defined($s) &&
+			($!{ENOBUFS} || $!{ENOMEM} || $!{ETOOMANYREFS}) &&
+			(++$try < 50) &&
+			warn "sleeping on sendmsg: $! (#$try)\n" &&
+			select(undef, undef, undef, 0.1) == 0);
+	$s;
 };
 
 *recv_cmd4 = sub ($$$) {
diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index e940d3c9d7f44710e86b8b1118f921cf8cea562e..6ca1ca2a0be3538b3cb9dc663422698b6b94952b 100644
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -34,6 +34,9 @@ #include <sys/uio.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <time.h>
+#include <stdio.h>
+#include <string.h>
 
 /* some platforms need alloca.h, but some don't */
 #if defined(__GNUC__) && !defined(alloca)
@@ -162,6 +165,22 @@ 	}
 	return (int)pid;
 }
 
+static int sleep_wait(unsigned *try, int err)
+{
+	const struct timespec req = { 0, 100000000 }; /* 100ms */
+	switch (err) {
+	case ENOBUFS: case ENOMEM: case ETOOMANYREFS:
+		if (++*try < 50) {
+			fprintf(stderr, "sleeping on sendmsg: %s (#%u)\n",
+				strerror(err), *try);
+			nanosleep(&req, NULL);
+			return 1;
+		}
+	default:
+		return 0;
+	}
+}
+
 #if defined(CMSG_SPACE) && defined(CMSG_LEN)
 #define SEND_FD_CAPA 10
 #define SEND_FD_SPACE (SEND_FD_CAPA * sizeof(int))
@@ -180,6 +199,7 @@ 	ssize_t sent;
 	AV *fds = (AV *)SvRV(svfds);
 	I32 i, nfds = av_len(fds) + 1;
 	int *fdp;
+	unsigned try = 0;
 
 	if (SvOK(data)) {
 		iov.iov_base = SvPV(data, dlen);
@@ -207,7 +227,9 @@ 			SV **fd = av_fetch(fds, i, 0);
 			*fdp++ = SvIV(*fd);
 		}
 	}
-	sent = sendmsg(PerlIO_fileno(s), &msg, flags);
+	do {
+		sent = sendmsg(PerlIO_fileno(s), &msg, flags);
+	} while (sent < 0 && sleep_wait(&try, errno));
 	return sent >= 0 ? newSViv(sent) : &PL_sv_undef;
 }
 
@@ -258,9 +280,6 @@ #include <sys/vfs.h>
 #include <linux/magic.h>
 #include <linux/fs.h>
 #include <dirent.h>
-#include <errno.h>
-#include <stdio.h>
-#include <string.h>
 
 void nodatacow_fd(int fd)
 {