From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753283Ab1DSQD2 (ORCPT ); Tue, 19 Apr 2011 12:03:28 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:55860 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752996Ab1DSQD0 (ORCPT ); Tue, 19 Apr 2011 12:03:26 -0400 Date: Tue, 19 Apr 2011 18:03:16 +0200 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Andrew Morton Subject: [GIT PULL] timer fixes Message-ID: <20110419160316.GA3377@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest timer-fixes-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timer-fixes-for-linus The posix clocks change fixes a pretty bad latency regression introduced in this cycle. (In hindsight this information should have been in the changelog) Thanks, Ingo ------------------> Axel Lin (1): RTC: rtc-omap: Fix a leak of the IRQ during init failure Richard Cochran (1): posix clocks: Replace mutex with reader/writer semaphore drivers/rtc/rtc-omap.c | 2 +- include/linux/posix-clock.h | 5 +++-- kernel/time/posix-clock.c | 24 +++++++++--------------- 3 files changed, 13 insertions(+), 18 deletions(-) diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c index de0dd7b..bcae8dd 100644 --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c @@ -394,7 +394,7 @@ static int __init omap_rtc_probe(struct platform_device *pdev) return 0; fail2: - free_irq(omap_rtc_timer, NULL); + free_irq(omap_rtc_timer, rtc); fail1: rtc_device_unregister(rtc); fail0: diff --git a/include/linux/posix-clock.h b/include/linux/posix-clock.h index 369e19d..7f1183d 100644 --- a/include/linux/posix-clock.h +++ b/include/linux/posix-clock.h @@ -24,6 +24,7 @@ #include #include #include +#include struct posix_clock; @@ -104,7 +105,7 @@ struct posix_clock_operations { * @ops: Functional interface to the clock * @cdev: Character device instance for this clock * @kref: Reference count. - * @mutex: Protects the 'zombie' field from concurrent access. + * @rwsem: Protects the 'zombie' field from concurrent access. * @zombie: If 'zombie' is true, then the hardware has disappeared. * @release: A function to free the structure when the reference count reaches * zero. May be NULL if structure is statically allocated. @@ -117,7 +118,7 @@ struct posix_clock { struct posix_clock_operations ops; struct cdev cdev; struct kref kref; - struct mutex mutex; + struct rw_semaphore rwsem; bool zombie; void (*release)(struct posix_clock *clk); }; diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c index 25028dd..c340ca6 100644 --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -19,7 +19,6 @@ */ #include #include -#include #include #include #include @@ -34,19 +33,19 @@ static struct posix_clock *get_posix_clock(struct file *fp) { struct posix_clock *clk = fp->private_data; - mutex_lock(&clk->mutex); + down_read(&clk->rwsem); if (!clk->zombie) return clk; - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); return NULL; } static void put_posix_clock(struct posix_clock *clk) { - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); } static ssize_t posix_clock_read(struct file *fp, char __user *buf, @@ -156,7 +155,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp) struct posix_clock *clk = container_of(inode->i_cdev, struct posix_clock, cdev); - mutex_lock(&clk->mutex); + down_read(&clk->rwsem); if (clk->zombie) { err = -ENODEV; @@ -172,7 +171,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp) fp->private_data = clk; } out: - mutex_unlock(&clk->mutex); + up_read(&clk->rwsem); return err; } @@ -211,25 +210,20 @@ int posix_clock_register(struct posix_clock *clk, dev_t devid) int err; kref_init(&clk->kref); - mutex_init(&clk->mutex); + init_rwsem(&clk->rwsem); cdev_init(&clk->cdev, &posix_clock_file_operations); clk->cdev.owner = clk->ops.owner; err = cdev_add(&clk->cdev, devid, 1); - if (err) - goto no_cdev; return err; -no_cdev: - mutex_destroy(&clk->mutex); - return err; } EXPORT_SYMBOL_GPL(posix_clock_register); static void delete_clock(struct kref *kref) { struct posix_clock *clk = container_of(kref, struct posix_clock, kref); - mutex_destroy(&clk->mutex); + if (clk->release) clk->release(clk); } @@ -238,9 +232,9 @@ void posix_clock_unregister(struct posix_clock *clk) { cdev_del(&clk->cdev); - mutex_lock(&clk->mutex); + down_write(&clk->rwsem); clk->zombie = true; - mutex_unlock(&clk->mutex); + up_write(&clk->rwsem); kref_put(&clk->kref, delete_clock); }