From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-659992-1519839260-2-3214861546415052539 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES unknown, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519839260; b=QXIihzieuQWE5IVGB9NVTjI1IPC/zdyaQfm+FRRvz1qzOAQ UM7BQtjNpcgAiyaLGVKrKtb2MPr0hkvfs11kYnIr4WaV9LpgcfWCDi/ZRf2E5aeO q5AxEejeavfL9sS/ScP6ojIFSBwlyVqCt2rISung1+5MAOISjCWhkM8cjLrAMR9S Tb0f6BejaN7XZfFPR09Rjub1HtD/V2kSzczZb2hvjoost5FfkPMVc37XtWFfOTHB YZ1CuL51de7Lw03xbDi+Czoq9AcTqwl5D6MzXpzMNGR3kMDPN6y4UOzHygecwCL1 RPSLOdpWcq1L7eHJtow5KA7zUgdPjoIOBKXWXgA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1519839260; bh=91ho9unljzP8/O5oylG lDj9ZKU576i8O6aLaqk38E8c=; b=wTJ2615czvPgmiQhik7UvVxBKMHiEGwDk2L p8AA8BhVlCzMeLBV5jttn1QqLo/CJ0hVECpj2UrQt/UcYhrZ2e9bvB5n9x34ToF8 bN/DRqlb+XPm0mSaUJ9+fieFKR2f6etZARePAaluICukIPNgxGETYGokp3iGYUro 2wyMh1rbBJJdWodl9Pg1cVJWYiX1ZNtld1hZJYk7RRexsFgv5y15wkXW+dCt+LXw ETecs6e+SXVcKrhGR4KMB5Jiak2arqBY+HkGRrTWubWsDwCHtEP+focLSbwjz6Ac amwlWbHnLWW8jV7Akwz4ngN3aMfEdBFgJfm9eFhSzHKrlqDn0Kw== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933327AbeB1Rb0 (ORCPT ); Wed, 28 Feb 2018 12:31:26 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33210 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932562AbeB1PWP (ORCPT ); Wed, 28 Feb 2018 10:22:15 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Takashi Iwai" Date: Wed, 28 Feb 2018 15:20:22 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 090/140] ALSA: pcm: Allow aborting mutex lock at OSS read/write loops In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.2.100-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 900498a34a3ac9c611e9b425094c8106bdd7dc1c upstream. PCM OSS read/write loops keep taking the mutex lock for the whole read/write, and this might take very long when the exceptionally high amount of data is given. Also, since it invokes with mutex_lock(), the concurrent read/write becomes unbreakable. This patch tries to address these issues by replacing mutex_lock() with mutex_lock_interruptible(), and also splits / re-takes the lock at each read/write period chunk, so that it can switch the context more finely if requested. Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- sound/core/oss/pcm_oss.c | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1375,8 +1375,11 @@ static ssize_t snd_pcm_oss_write1(struct if ((tmp = snd_pcm_oss_make_ready(substream)) < 0) return tmp; - mutex_lock(&runtime->oss.params_lock); while (bytes > 0) { + if (mutex_lock_interruptible(&runtime->oss.params_lock)) { + tmp = -ERESTARTSYS; + break; + } if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) { tmp = bytes; if (tmp + runtime->oss.buffer_used > runtime->oss.period_bytes) @@ -1420,18 +1423,18 @@ static ssize_t snd_pcm_oss_write1(struct xfer += tmp; if ((substream->f_flags & O_NONBLOCK) != 0 && tmp != runtime->oss.period_bytes) - break; + tmp = -EAGAIN; } + err: + mutex_unlock(&runtime->oss.params_lock); + if (tmp < 0) + break; if (signal_pending(current)) { tmp = -ERESTARTSYS; - goto err; + break; } + tmp = 0; } - mutex_unlock(&runtime->oss.params_lock); - return xfer; - - err: - mutex_unlock(&runtime->oss.params_lock); return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp; } @@ -1479,8 +1482,11 @@ static ssize_t snd_pcm_oss_read1(struct if ((tmp = snd_pcm_oss_make_ready(substream)) < 0) return tmp; - mutex_lock(&runtime->oss.params_lock); while (bytes > 0) { + if (mutex_lock_interruptible(&runtime->oss.params_lock)) { + tmp = -ERESTARTSYS; + break; + } if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) { if (runtime->oss.buffer_used == 0) { tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1); @@ -1511,16 +1517,16 @@ static ssize_t snd_pcm_oss_read1(struct bytes -= tmp; xfer += tmp; } + err: + mutex_unlock(&runtime->oss.params_lock); + if (tmp < 0) + break; if (signal_pending(current)) { tmp = -ERESTARTSYS; - goto err; + break; } + tmp = 0; } - mutex_unlock(&runtime->oss.params_lock); - return xfer; - - err: - mutex_unlock(&runtime->oss.params_lock); return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp; }