From: Daniel P. Berrangé Date: Tue, 10 Jun 2025 12:36:50 +0000 (+0100) Subject: hw/audio/sb16: skip automatic zero-init of large array X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=30c82f6657c1ee9fbb5473924b4d3273f214bd6f;p=thirdparty%2Fqemu.git hw/audio/sb16: skip automatic zero-init of large array The 'write_audio' method has a 4k byte array used for copying data between the audio backend and device. Skip the automatic zero-init of this array to eliminate the performance overhead in the I/O hot path. The 'tmpbuf' array will be fully initialized when reading data from device memory. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Message-id: 20250610123709.835102-13-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- diff --git a/hw/audio/sb16.c b/hw/audio/sb16.c index 19fd3b9020..bac64118fe 100644 --- a/hw/audio/sb16.c +++ b/hw/audio/sb16.c @@ -1181,7 +1181,7 @@ static int write_audio (SB16State *s, int nchan, int dma_pos, IsaDma *isa_dma = nchan == s->dma ? s->isa_dma : s->isa_hdma; IsaDmaClass *k = ISADMA_GET_CLASS(isa_dma); int temp, net; - uint8_t tmpbuf[4096]; + QEMU_UNINITIALIZED uint8_t tmpbuf[4096]; temp = len; net = 0;