111 lines
3.9 KiB
Diff
111 lines
3.9 KiB
Diff
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From d824b461ae807ea436e2df36da9c2212e485e3e6 Mon Sep 17 00:00:00 2001
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From: Takashi Iwai <tiwai@suse.de>
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Date: Fri, 19 Jun 2020 18:40:46 +0200
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Subject: [PATCH 06/32] pcm: dmix: Fix semaphore usage with lockless operation
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As Maarten Baert recently reported, the current dmix code applies the
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semaphore unnecessarily around mixing streams even when the lockless
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mix operation is used on x86. This was rather introduced mistakenly
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at the commit 267d7c728196 ("Add support of little-endian on
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i386/x86_64 dmix") where the generic dmix code was included on x86,
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too.
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For achieving the original performance back, this patch changes the
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semaphore handling to be checked at run time instead of statically at
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compile time.
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Reviewed-by: Jaroslav Kysela <perex@perex.cz>
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Signed-off-by: Takashi Iwai <tiwai@suse.de>
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---
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src/pcm/pcm_direct.h | 1 +
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src/pcm/pcm_dmix.c | 18 +++++++++++-------
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src/pcm/pcm_dmix_generic.c | 2 +-
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src/pcm/pcm_dmix_i386.c | 1 +
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src/pcm/pcm_dmix_x86_64.c | 1 +
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5 files changed, 15 insertions(+), 8 deletions(-)
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diff --git a/src/pcm/pcm_direct.h b/src/pcm/pcm_direct.h
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index 8a236970a3a1..2150bce15449 100644
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--- a/src/pcm/pcm_direct.h
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+++ b/src/pcm/pcm_direct.h
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@@ -186,6 +186,7 @@ struct snd_pcm_direct {
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mix_areas_32_t *remix_areas_32;
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mix_areas_24_t *remix_areas_24;
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mix_areas_u8_t *remix_areas_u8;
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+ unsigned int use_sem;
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} dmix;
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struct {
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unsigned long long chn_mask;
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diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c
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index 843fa3168756..e9343b19a536 100644
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--- a/src/pcm/pcm_dmix.c
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+++ b/src/pcm/pcm_dmix.c
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@@ -292,13 +292,17 @@ static void remix_areas(snd_pcm_direct_t *dmix,
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* the area via semaphore
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*/
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#ifndef DOC_HIDDEN
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-#ifdef NO_CONCURRENT_ACCESS
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-#define dmix_down_sem(dmix) snd_pcm_direct_semaphore_down(dmix, DIRECT_IPC_SEM_CLIENT)
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-#define dmix_up_sem(dmix) snd_pcm_direct_semaphore_up(dmix, DIRECT_IPC_SEM_CLIENT)
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-#else
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-#define dmix_down_sem(dmix)
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-#define dmix_up_sem(dmix)
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-#endif
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+static void dmix_down_sem(snd_pcm_direct_t *dmix)
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+{
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+ if (dmix->u.dmix.use_sem)
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+ snd_pcm_direct_semaphore_down(dmix, DIRECT_IPC_SEM_CLIENT);
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+}
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+
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+static void dmix_up_sem(snd_pcm_direct_t *dmix)
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+{
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+ if (dmix->u.dmix.use_sem)
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+ snd_pcm_direct_semaphore_up(dmix, DIRECT_IPC_SEM_CLIENT);
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+}
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#endif
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/*
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diff --git a/src/pcm/pcm_dmix_generic.c b/src/pcm/pcm_dmix_generic.c
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index 40c08747a74a..8a5b6f148556 100644
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--- a/src/pcm/pcm_dmix_generic.c
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+++ b/src/pcm/pcm_dmix_generic.c
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@@ -43,7 +43,6 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
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#ifndef ARCH_ADD
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#define ARCH_ADD(p,a) (*(p) += (a))
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#define ARCH_CMPXCHG(p,a,b) (*(p)) /* fake */
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-#define NO_CONCURRENT_ACCESS /* use semaphore to avoid race */
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#define IS_CONCURRENT 0 /* no race check */
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#endif
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@@ -530,6 +529,7 @@ static void generic_mix_select_callbacks(snd_pcm_direct_t *dmix)
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dmix->u.dmix.mix_areas_u8 = generic_mix_areas_u8;
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dmix->u.dmix.remix_areas_24 = generic_remix_areas_24;
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dmix->u.dmix.remix_areas_u8 = generic_remix_areas_u8;
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+ dmix->u.dmix.use_sem = 1;
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}
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#endif
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diff --git a/src/pcm/pcm_dmix_i386.c b/src/pcm/pcm_dmix_i386.c
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index 1ab983a8a373..82a91c5c2897 100644
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--- a/src/pcm/pcm_dmix_i386.c
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+++ b/src/pcm/pcm_dmix_i386.c
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@@ -135,4 +135,5 @@ static void mix_select_callbacks(snd_pcm_direct_t *dmix)
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dmix->u.dmix.mix_areas_24 = smp > 1 ? mix_areas_24_smp: mix_areas_24;
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dmix->u.dmix.remix_areas_24 = smp > 1 ? remix_areas_24_smp: remix_areas_24;
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}
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+ dmix->u.dmix.use_sem = 0;
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}
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diff --git a/src/pcm/pcm_dmix_x86_64.c b/src/pcm/pcm_dmix_x86_64.c
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index 34c40d4e9d1d..4d882bfd01bf 100644
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--- a/src/pcm/pcm_dmix_x86_64.c
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+++ b/src/pcm/pcm_dmix_x86_64.c
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@@ -102,4 +102,5 @@ static void mix_select_callbacks(snd_pcm_direct_t *dmix)
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dmix->u.dmix.remix_areas_32 = smp > 1 ? remix_areas_32_smp : remix_areas_32;
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dmix->u.dmix.mix_areas_24 = smp > 1 ? mix_areas_24_smp : mix_areas_24;
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dmix->u.dmix.remix_areas_24 = smp > 1 ? remix_areas_24_smp : remix_areas_24;
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+ dmix->u.dmix.use_sem = 0;
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}
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--
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2.16.4
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