From 2e438da4929018c62609381e1156aac0b2fe3de3 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 10 Jun 2025 13:36:48 +0100 Subject: [PATCH] hw/audio/gus: skip automatic zero-init of large array MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The 'GUS_read_DMA' 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: 20250610123709.835102-11-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- hw/audio/gus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/audio/gus.c b/hw/audio/gus.c index 87e8634893..c36df0240f 100644 --- a/hw/audio/gus.c +++ b/hw/audio/gus.c @@ -183,7 +183,7 @@ static int GUS_read_DMA (void *opaque, int nchan, int dma_pos, int dma_len) { GUSState *s = opaque; IsaDmaClass *k = ISADMA_GET_CLASS(s->isa_dma); - char tmpbuf[4096]; + QEMU_UNINITIALIZED char tmpbuf[4096]; int pos = dma_pos, mode, left = dma_len - dma_pos; ldebug ("read DMA %#x %d\n", dma_pos, dma_len); -- 2.39.5