51 lines
1.8 KiB
Diff
51 lines
1.8 KiB
Diff
From ca2cc0385d97cea66cd54ee42553f385c403d4a6 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
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Date: Tue, 10 Jun 2025 13:36:46 +0100
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Subject: [PATCH] hw/audio/cs4231a: skip automatic zero-init of large arrays
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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The 'cs_write_audio' method has a pair of byte arrays, one 4k in size
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and one 8k, which are used in converting audio samples. Skip the
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automatic zero-init of these arrays to eliminate the performance
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overhead in the I/O hot path.
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The 'tmpbuf' array will be fully initialized when reading a block of
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data from the guest. The 'linbuf' array will be fully initialized
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when converting the audio samples.
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Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
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Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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Message-id: 20250610123709.835102-9-berrange@redhat.com
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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---
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hw/audio/cs4231a.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/hw/audio/cs4231a.c b/hw/audio/cs4231a.c
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index eb9a45805b..6dfff202ff 100644
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--- a/hw/audio/cs4231a.c
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+++ b/hw/audio/cs4231a.c
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@@ -528,7 +528,7 @@ static int cs_write_audio (CSState *s, int nchan, int dma_pos,
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int dma_len, int len)
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{
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int temp, net;
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- uint8_t tmpbuf[4096];
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+ QEMU_UNINITIALIZED uint8_t tmpbuf[4096];
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IsaDmaClass *k = ISADMA_GET_CLASS(s->isa_dma);
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temp = len;
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@@ -547,7 +547,7 @@ static int cs_write_audio (CSState *s, int nchan, int dma_pos,
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copied = k->read_memory(s->isa_dma, nchan, tmpbuf, dma_pos, to_copy);
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if (s->tab) {
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int i;
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- int16_t linbuf[4096];
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+ QEMU_UNINITIALIZED int16_t linbuf[4096];
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for (i = 0; i < copied; ++i)
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linbuf[i] = s->tab[tmpbuf[i]];
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--
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2.47.3
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