From ef07fc569ae2a50f54f8bf29f09555cb0e8b08db Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 10 Jun 2025 13:36:49 +0100 Subject: [PATCH 19/43] hw/audio/marvell_88w8618: skip automatic zero-init of large array MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Stefan Hajnoczi RH-MergeRequest: 381: Solve -ftrivial-auto-var-init performance regression with QEMU_UNINITIALIZED RH-Jira: RHEL-95479 RH-Acked-by: Miroslav Rezanina RH-Commit: [11/31] c45c78043e51ac3195e76aaf0b745dd41c8d8345 (stefanha/centos-stream-qemu-kvm) The 'mv88w8618_audio_callback' 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 'buf' array will be fully initialized when reading data from device memory. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Message-id: 20250610123709.835102-12-berrange@redhat.com [Fixed hw/audio/gus in commit message --Stefan] Signed-off-by: Stefan Hajnoczi (cherry picked from commit 5b6cd5c5df4229972d8a0fd9dd9a089a1644d6ba) Signed-off-by: Stefan Hajnoczi --- hw/audio/marvell_88w8618.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/audio/marvell_88w8618.c b/hw/audio/marvell_88w8618.c index 28f9af320d..31a73f53b9 100644 --- a/hw/audio/marvell_88w8618.c +++ b/hw/audio/marvell_88w8618.c @@ -66,7 +66,7 @@ static void mv88w8618_audio_callback(void *opaque, int free_out, int free_in) { mv88w8618_audio_state *s = opaque; int16_t *codec_buffer; - int8_t buf[4096]; + QEMU_UNINITIALIZED int8_t buf[4096]; int8_t *mem_buffer; int pos, block_size; -- 2.39.3