From patchwork Tue Nov 4 13:28:12 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 5227751 X-Patchwork-Delegate: tiwai@suse.de Return-Path: X-Original-To: patchwork-alsa-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 04EFA9F3EE for ; Tue, 4 Nov 2014 13:30:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0DD77201C0 for ; Tue, 4 Nov 2014 13:30:18 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.kernel.org (Postfix) with ESMTP id 8879A2017A for ; Tue, 4 Nov 2014 13:30:16 +0000 (UTC) Received: by alsa0.perex.cz (Postfix, from userid 1000) id AF39A2619E7; Tue, 4 Nov 2014 14:30:15 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from alsa0.perex.cz (localhost [IPv6:::1]) by alsa0.perex.cz (Postfix) with ESMTP id 7AA62261606; Tue, 4 Nov 2014 14:28:51 +0100 (CET) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id BDFC12615DC; Tue, 4 Nov 2014 14:28:48 +0100 (CET) Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 2DD2C261534 for ; Tue, 4 Nov 2014 14:28:20 +0100 (CET) Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 656C1AD66 for ; Tue, 4 Nov 2014 13:28:19 +0000 (UTC) From: Takashi Iwai To: alsa-devel@alsa-project.org Date: Tue, 4 Nov 2014 14:28:12 +0100 Message-Id: <1415107696-17123-2-git-send-email-tiwai@suse.de> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1415107696-17123-1-git-send-email-tiwai@suse.de> References: <1415107696-17123-1-git-send-email-tiwai@suse.de> Subject: [alsa-devel] [PATCH 1/5] ALSA: pcm: Simplify snd_pcm_action_lock_irq() X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP The function snd_pcm_action_lock_irq() can be much simplified by simply wrapping snd_pcm_action() with the stream lock. This was rather the original idea, but later it was open coded for optimization. However, looking at the optimization part closely, one notices that the probability of the optimized path is quite low; in normal situations, the linked stream action happens only for the triggered substream, thus the operation becomes identical. So the code simplification has a clear win, especially because we have now doubly codes for both atomic and non-atomic locks. Signed-off-by: Takashi Iwai --- sound/core/pcm_native.c | 41 +++-------------------------------------- 1 file changed, 3 insertions(+), 38 deletions(-) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 4d5795d8b9f7..b92b605fc784 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -947,28 +947,6 @@ static int snd_pcm_action(struct action_ops *ops, return res; } -static int snd_pcm_action_lock_mutex(struct action_ops *ops, - struct snd_pcm_substream *substream, - int state) -{ - int res; - - down_read(&snd_pcm_link_rwsem); - if (snd_pcm_stream_linked(substream)) { - mutex_lock(&substream->group->mutex); - mutex_lock(&substream->self_group.mutex); - res = snd_pcm_action_group(ops, substream, state, 1); - mutex_unlock(&substream->self_group.mutex); - mutex_unlock(&substream->group->mutex); - } else { - mutex_lock(&substream->self_group.mutex); - res = snd_pcm_action_single(ops, substream, state); - mutex_unlock(&substream->self_group.mutex); - } - up_read(&snd_pcm_link_rwsem); - return res; -} - /* * Note: don't use any locks before */ @@ -978,22 +956,9 @@ static int snd_pcm_action_lock_irq(struct action_ops *ops, { int res; - if (substream->pcm->nonatomic) - return snd_pcm_action_lock_mutex(ops, substream, state); - - read_lock_irq(&snd_pcm_link_rwlock); - if (snd_pcm_stream_linked(substream)) { - spin_lock(&substream->group->lock); - spin_lock(&substream->self_group.lock); - res = snd_pcm_action_group(ops, substream, state, 1); - spin_unlock(&substream->self_group.lock); - spin_unlock(&substream->group->lock); - } else { - spin_lock(&substream->self_group.lock); - res = snd_pcm_action_single(ops, substream, state); - spin_unlock(&substream->self_group.lock); - } - read_unlock_irq(&snd_pcm_link_rwlock); + snd_pcm_stream_lock_irq(substream); + res = snd_pcm_action(ops, substream, state); + snd_pcm_stream_unlock_irq(substream); return res; }