From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751605AbaILEms (ORCPT ); Fri, 12 Sep 2014 00:42:48 -0400 Received: from homie.mail.dreamhost.com ([208.97.132.208]:53013 "EHLO homiemail-a14.g.dreamhost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbaILEmr (ORCPT ); Fri, 12 Sep 2014 00:42:47 -0400 Message-ID: <1410496890.2166.11.camel@linux-t7sj.site> Subject: [PATCH 8/9] locktorture: Support rwsems From: Davidlohr Bueso To: paulmck@linux.vnet.ibm.com Cc: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, dave@stgolabs.net, dbueso@suse.de Date: Thu, 11 Sep 2014 21:41:30 -0700 In-Reply-To: <1410493224-3312-1-git-send-email-dave@stgolabs.net> References: <1410493224-3312-1-git-send-email-dave@stgolabs.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can easily do so with our new reader lock support. Just an arbitrary design default: readers have higher (5x) critical region latencies than writers: 50 ms and 10 ms, respectively. Signed-off-by: Davidlohr Bueso --- Documentation/locking/locktorture.txt | 2 ++ kernel/locking/locktorture.c | 68 ++++++++++++++++++++++++++++++++++- 2 files changed, 69 insertions(+), 1 deletion(-) diff --git a/Documentation/locking/locktorture.txt b/Documentation/locking/locktorture.txt index 1bdeb71..f7d99e2 100644 --- a/Documentation/locking/locktorture.txt +++ b/Documentation/locking/locktorture.txt @@ -47,6 +47,8 @@ torture_type Type of lock to torture. By default, only spinlocks will o "mutex_lock": mutex_lock() and mutex_unlock() pairs. + o "rwsem_lock": read/write down() and up() semaphore pairs. + torture_runnable Start locktorture at module init. By default it will begin once the module is loaded. diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index c1073d7..8480118 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -265,6 +265,71 @@ static struct lock_torture_ops mutex_lock_ops = { .name = "mutex_lock" }; +static DECLARE_RWSEM(torture_rwsem); +static int torture_rwsem_down_write(void) __acquires(torture_rwsem) +{ + down_write(&torture_rwsem); + return 0; +} + +static void torture_rwsem_write_delay(struct torture_random_state *trsp) +{ + const unsigned long longdelay_ms = 100; + + /* We want a long delay occasionally to force massive contention. */ + if (!(torture_random(trsp) % + (nrealwriters_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms * 10); + else + mdelay(longdelay_ms / 10); +#ifdef CONFIG_PREEMPT + if (!(torture_random(trsp) % (nrealwriters_stress * 20000))) + preempt_schedule(); /* Allow test to be preempted. */ +#endif +} + +static void torture_rwsem_up_write(void) __releases(torture_rwsem) +{ + up_write(&torture_rwsem); +} + +static int torture_rwsem_down_read(void) __acquires(torture_rwsem) +{ + down_read(&torture_rwsem); + return 0; +} + +static void torture_rwsem_read_delay(struct torture_random_state *trsp) +{ + const unsigned long longdelay_ms = 100; + + /* We want a long delay occasionally to force massive contention. */ + if (!(torture_random(trsp) % + (nrealwriters_stress * 2000 * longdelay_ms))) + mdelay(longdelay_ms * 2); + else + mdelay(longdelay_ms / 2); +#ifdef CONFIG_PREEMPT + if (!(torture_random(trsp) % (nrealreaders_stress * 20000))) + preempt_schedule(); /* Allow test to be preempted. */ +#endif +} + +static void torture_rwsem_up_read(void) __releases(torture_rwsem) +{ + up_read(&torture_rwsem); +} + +static struct lock_torture_ops rwsem_lock_ops = { + .writelock = torture_rwsem_down_write, + .write_delay = torture_rwsem_write_delay, + .writeunlock = torture_rwsem_up_write, + .readlock = torture_rwsem_down_read, + .read_delay = torture_rwsem_read_delay, + .readunlock = torture_rwsem_up_read, + .name = "rwsem_lock" +}; + /* * Lock torture writer kthread. Repeatedly acquires and releases * the lock, checking for duplicate acquisitions. @@ -467,7 +532,8 @@ static int __init lock_torture_init(void) int i, j; int firsterr = 0; static struct lock_torture_ops *torture_ops[] = { - &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops, &mutex_lock_ops, + &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops, + &mutex_lock_ops, &rwsem_lock_ops, }; if (!torture_init_begin(torture_type, verbose, &torture_runnable)) -- 1.8.4.5