From: Daniel P. Berrangé Date: Tue, 10 Jun 2025 12:36:44 +0000 (+0100) Subject: chardev/char-socket: skip automatic zero-init of large array X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9a23075cef1ac6e73a95a489ac72f41c573ceb9b;p=thirdparty%2Fqemu.git chardev/char-socket: skip automatic zero-init of large array The 'tcp_chr_read' method has a 4k byte array used for copying data between the socket and device. Skip the automatic zero-init of this array to eliminate the performance overhead in the I/O hot path. The 'buf' array will be fully initialized when reading data off the network socket. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Message-id: 20250610123709.835102-7-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- diff --git a/chardev/char-socket.c b/chardev/char-socket.c index e8dd2931dc..1e8313915b 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -497,7 +497,7 @@ static gboolean tcp_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque) { Chardev *chr = CHARDEV(opaque); SocketChardev *s = SOCKET_CHARDEV(opaque); - uint8_t buf[CHR_READ_BUF_LEN]; + QEMU_UNINITIALIZED uint8_t buf[CHR_READ_BUF_LEN]; int len, size; if ((s->state != TCP_CHARDEV_STATE_CONNECTED) ||