From patchwork Tue Dec 13 20:48:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 13072420 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44251C4332F for ; Tue, 13 Dec 2022 20:48:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236668AbiLMUsr (ORCPT ); Tue, 13 Dec 2022 15:48:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236535AbiLMUsq (ORCPT ); Tue, 13 Dec 2022 15:48:46 -0500 Received: from mail-qt1-x835.google.com (mail-qt1-x835.google.com [IPv6:2607:f8b0:4864:20::835]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 596C217400 for ; Tue, 13 Dec 2022 12:48:44 -0800 (PST) Received: by mail-qt1-x835.google.com with SMTP id g7so932217qts.1 for ; Tue, 13 Dec 2022 12:48:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=GgB8o7r5q35ufkQfTVEI1g6ta2jLelpUzptLG5w6In4=; b=D+kO/iR7y9EiLfw2ghUa2eLjJOuj2TVXIaYhzIHlfLueijDowkxBcWTHwLbzkg8NSu zvhJ9QqgDIVBoZZNwirnaTUg6BbomKH2yuhYljYbWrBpk6Qllh5Cd4HB0PfMOYMpt9VM 2WZCZuvIYejfh4A5IQ2IjyKRrN/nHXj8tP+dw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=GgB8o7r5q35ufkQfTVEI1g6ta2jLelpUzptLG5w6In4=; b=Vugq2D+TDa92xvq8d6QqYaXSYCwHow3PZS/fVXhaVwbO1aekjt2tlpL+4yraDUMeAz DSgZsS9JumDnXrYHAKVbVkUSLeKJeenvkkDolJKMprc++K7XRxfUxMSUD6THbghuYxJ5 Xs0GDMu5ErG+KdjQyvn4BOHZYQF1M4d/UFhdEyAvCRJedAYR45X7hsQ1OXusSB17Nud7 hqQLgOgghSCMGL2DzZhXIv3C4Ixn72f0sWt9NUK+HVX4YN8otw8A2zsnnoZqIDhGlwmG dBvB+EJypKGglFX0MkNchMLPlmIeNmsrSUEnKPXchGeBux5Ma0ONyKc96gb/+wePZEDc vWXA== X-Gm-Message-State: ANoB5pkWoRiJHT+Xf8Zu2hw4R6PliKBmAjXEGb4LA678jAy7SNT4UX2H 1m2q+uLsYLNNaAulSWFXhEzIGw== X-Google-Smtp-Source: AA0mqf5cnanCMQPwlbQAedBXFJ/TiioaUyby/c5MhJ0ZKix8MUewm+FgZgdW7zncCqjjO3uqi6QehA== X-Received: by 2002:ac8:534c:0:b0:3a4:ea5c:6fc2 with SMTP id d12-20020ac8534c000000b003a4ea5c6fc2mr6670731qto.52.1670964523400; Tue, 13 Dec 2022 12:48:43 -0800 (PST) Received: from joelboxx.c.googlers.com.com (228.221.150.34.bc.googleusercontent.com. [34.150.221.228]) by smtp.gmail.com with ESMTPSA id h3-20020a05620a400300b006fc447eebe5sm8562757qko.27.2022.12.13.12.48.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Dec 2022 12:48:42 -0800 (PST) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Davidlohr Bueso , Josh Triplett , "Paul E. McKenney" , rcu@vger.kernel.org, connoro@google.com Subject: [PATCH v3 rcu/dev 1/2] locktorture: Allow non-rtmutex lock types to be boosted Date: Tue, 13 Dec 2022 20:48:38 +0000 Message-Id: <20221213204839.321027-1-joel@joelfernandes.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Currently RT boosting is only done for rtmutex_lock, however with proxy execution, we also have the mutex_lock participating in priorities. To exercise the testing better, add RT boosting to other lock testing types as well, using a new knob (rt_boost). Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=1 locktorture.nlocks=3 For the rtmutex test, rt_boost is always enabled even if disabling is requested. Signed-off-by: Joel Fernandes (Google) --- kernel/locking/locktorture.c | 99 ++++++++++++++++++++---------------- 1 file changed, 56 insertions(+), 43 deletions(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 9c2fb613a55d..e2271e8fc302 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -46,6 +46,8 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); +torture_param(int, rt_boost, 2, + "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); @@ -127,15 +129,49 @@ static void torture_lock_busted_write_unlock(int tid __maybe_unused) /* BUGGY, do not use in real life!!! */ } -static void torture_boost_dummy(struct torture_random_state *trsp) +static void __torture_rt_boost(struct torture_random_state *trsp) { - /* Only rtmutexes care about priority */ + const unsigned int factor = 50000; /* yes, quite arbitrary */ + + if (!rt_task(current)) { + /* + * Boost priority once every ~50k operations. When the + * task tries to take the lock, the rtmutex it will account + * for the new priority, and do any corresponding pi-dance. + */ + if (trsp && !(torture_random(trsp) % + (cxt.nrealwriters_stress * factor))) { + sched_set_fifo(current); + } else /* common case, do nothing */ + return; + } else { + /* + * The task will remain boosted for another ~500k operations, + * then restored back to its original prio, and so forth. + * + * When @trsp is nil, we want to force-reset the task for + * stopping the kthread. + */ + if (!trsp || !(torture_random(trsp) % + (cxt.nrealwriters_stress * factor * 2))) { + sched_set_normal(current, 0); + } else /* common case, do nothing */ + return; + } +} + +static void torture_rt_boost(struct torture_random_state *trsp) +{ + if (rt_boost != 2) + return; + + __torture_rt_boost(trsp); } static struct lock_torture_ops lock_busted_ops = { .writelock = torture_lock_busted_write_lock, .write_delay = torture_lock_busted_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_lock_busted_write_unlock, .readlock = NULL, .read_delay = NULL, @@ -179,7 +215,7 @@ __releases(torture_spinlock) static struct lock_torture_ops spin_lock_ops = { .writelock = torture_spin_lock_write_lock, .write_delay = torture_spin_lock_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_spin_lock_write_unlock, .readlock = NULL, .read_delay = NULL, @@ -206,7 +242,7 @@ __releases(torture_spinlock) static struct lock_torture_ops spin_lock_irq_ops = { .writelock = torture_spin_lock_write_lock_irq, .write_delay = torture_spin_lock_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_lock_spin_write_unlock_irq, .readlock = NULL, .read_delay = NULL, @@ -275,7 +311,7 @@ __releases(torture_rwlock) static struct lock_torture_ops rw_lock_ops = { .writelock = torture_rwlock_write_lock, .write_delay = torture_rwlock_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_rwlock_write_unlock, .readlock = torture_rwlock_read_lock, .read_delay = torture_rwlock_read_delay, @@ -318,7 +354,7 @@ __releases(torture_rwlock) static struct lock_torture_ops rw_lock_irq_ops = { .writelock = torture_rwlock_write_lock_irq, .write_delay = torture_rwlock_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_rwlock_write_unlock_irq, .readlock = torture_rwlock_read_lock_irq, .read_delay = torture_rwlock_read_delay, @@ -358,7 +394,7 @@ __releases(torture_mutex) static struct lock_torture_ops mutex_lock_ops = { .writelock = torture_mutex_lock, .write_delay = torture_mutex_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_mutex_unlock, .readlock = NULL, .read_delay = NULL, @@ -456,7 +492,7 @@ static struct lock_torture_ops ww_mutex_lock_ops = { .exit = torture_ww_mutex_exit, .writelock = torture_ww_mutex_lock, .write_delay = torture_mutex_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_ww_mutex_unlock, .readlock = NULL, .read_delay = NULL, @@ -474,37 +510,6 @@ __acquires(torture_rtmutex) return 0; } -static void torture_rtmutex_boost(struct torture_random_state *trsp) -{ - const unsigned int factor = 50000; /* yes, quite arbitrary */ - - if (!rt_task(current)) { - /* - * Boost priority once every ~50k operations. When the - * task tries to take the lock, the rtmutex it will account - * for the new priority, and do any corresponding pi-dance. - */ - if (trsp && !(torture_random(trsp) % - (cxt.nrealwriters_stress * factor))) { - sched_set_fifo(current); - } else /* common case, do nothing */ - return; - } else { - /* - * The task will remain boosted for another ~500k operations, - * then restored back to its original prio, and so forth. - * - * When @trsp is nil, we want to force-reset the task for - * stopping the kthread. - */ - if (!trsp || !(torture_random(trsp) % - (cxt.nrealwriters_stress * factor * 2))) { - sched_set_normal(current, 0); - } else /* common case, do nothing */ - return; - } -} - static void torture_rtmutex_delay(struct torture_random_state *trsp) { const unsigned long shortdelay_us = 2; @@ -530,10 +535,18 @@ __releases(torture_rtmutex) rt_mutex_unlock(&torture_rtmutex); } +static void torture_rt_boost_rtmutex(struct torture_random_state *trsp) +{ + if (!rt_boost) + return; + + __torture_rt_boost(trsp); +} + static struct lock_torture_ops rtmutex_lock_ops = { .writelock = torture_rtmutex_lock, .write_delay = torture_rtmutex_delay, - .task_boost = torture_rtmutex_boost, + .task_boost = torture_rt_boost_rtmutex, .writeunlock = torture_rtmutex_unlock, .readlock = NULL, .read_delay = NULL, @@ -600,7 +613,7 @@ __releases(torture_rwsem) static struct lock_torture_ops rwsem_lock_ops = { .writelock = torture_rwsem_down_write, .write_delay = torture_rwsem_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_rwsem_up_write, .readlock = torture_rwsem_down_read, .read_delay = torture_rwsem_read_delay, @@ -652,7 +665,7 @@ static struct lock_torture_ops percpu_rwsem_lock_ops = { .exit = torture_percpu_rwsem_exit, .writelock = torture_percpu_rwsem_down_write, .write_delay = torture_rwsem_write_delay, - .task_boost = torture_boost_dummy, + .task_boost = torture_rt_boost, .writeunlock = torture_percpu_rwsem_up_write, .readlock = torture_percpu_rwsem_down_read, .read_delay = torture_rwsem_read_delay, From patchwork Tue Dec 13 20:48:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 13072421 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83A84C4332F for ; Tue, 13 Dec 2022 20:48:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236671AbiLMUst (ORCPT ); Tue, 13 Dec 2022 15:48:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236698AbiLMUsr (ORCPT ); Tue, 13 Dec 2022 15:48:47 -0500 Received: from mail-qv1-xf35.google.com (mail-qv1-xf35.google.com [IPv6:2607:f8b0:4864:20::f35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB4B417890 for ; Tue, 13 Dec 2022 12:48:45 -0800 (PST) Received: by mail-qv1-xf35.google.com with SMTP id a17so11214311qvt.9 for ; Tue, 13 Dec 2022 12:48:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=1/mAzkHKq4wIiV8zGJG5Z4ta1NtZeQngWYqtEq72j8s=; b=Nmlbcj+lt1FKvUbPHui2UR4Mnuw5qu7mvQV+fIvRKu/SfijMrqYl6GYbfIwUBm9zpX rroQnWImlKdXex5c6VrW5fSJsXFQFjmPZW9miwqosak2X2kLhTlSMit6XCsu98i0sIjQ 78yxgnE8I3sDlCHFMhVVqCiSzIkmPoGsKVBYc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1/mAzkHKq4wIiV8zGJG5Z4ta1NtZeQngWYqtEq72j8s=; b=1TW8cYCAUOahJTfl+pplxM4dkd8eVKPIpfl6CZ0n/4vqeCL0xPXOQ9EtsOHSJfI5QU 7cpTD1Sfz+oQfWN3GxWqu6EG2vUzOlbVB3hlApZMYmilQQpI3rNhiRzLpLPyF4CLNz7e U/BlMhAZGIxdxrzX+o1Oqp7gzlzepdXvavqWWmoPvn1/Y5LWRdfagENRr6JEasi3Wttw bpyIlUuXMAW8rCMec70trA3/cO5TxkvKkjvDeyfINLF9cSZRhRP2TFCchtjyB/bV3FQd PHwxtTeTfPYcQNWw122AEzzDzBzeLb8b/JN40bPxnoc38OjgCjMyGDmUi/h37zJLonML VnSQ== X-Gm-Message-State: ANoB5pmYdMXy1K58JCYq4IXSotlQUAYIw4uan1sZ52h94Yg+irwET6Ww nzW8N0ky+Y5UT04BEoBKA48W4Q== X-Google-Smtp-Source: AA0mqf7uPS5m23dd59Pnh/Yh0b3PScpNumZ/g82OZq5LpWfP7mVPHkBqxpx4Ov06Nm5QDut8cl/tZw== X-Received: by 2002:a05:6214:14a6:b0:4c6:fa63:60ed with SMTP id bo6-20020a05621414a600b004c6fa6360edmr26313085qvb.47.1670964524781; Tue, 13 Dec 2022 12:48:44 -0800 (PST) Received: from joelboxx.c.googlers.com.com (228.221.150.34.bc.googleusercontent.com. [34.150.221.228]) by smtp.gmail.com with ESMTPSA id h3-20020a05620a400300b006fc447eebe5sm8562757qko.27.2022.12.13.12.48.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Dec 2022 12:48:43 -0800 (PST) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Davidlohr Bueso , Josh Triplett , "Paul E. McKenney" , rcu@vger.kernel.org, connoro@google.com Subject: [PATCH v3 rcu/dev 2/2] locktorture: Make the rt_boost factor a tunable Date: Tue, 13 Dec 2022 20:48:39 +0000 Message-Id: <20221213204839.321027-2-joel@joelfernandes.org> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog In-Reply-To: <20221213204839.321027-1-joel@joelfernandes.org> References: <20221213204839.321027-1-joel@joelfernandes.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org The rt boosting in locktorture has a factor variable s currently large enough that boosting only happens once every minute or so. Add a tunable to reduce the factor so that boosting happens more often, to test paths and arrive at failure modes earlier. With this change, I can set the factor to like 50 and have the boosting happens every 10 seconds or so. Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=50 locktorture.nlocks=3 [ Apply Davidlohr Bueso feedback on quoting rt_boost_factor. ] Signed-off-by: Joel Fernandes (Google) --- kernel/locking/locktorture.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index e2271e8fc302..87e861da0ad5 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -48,6 +48,7 @@ torture_param(int, stat_interval, 60, torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); torture_param(int, rt_boost, 2, "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); +torture_param(int, rt_boost_factor, 50, "A factor determining how often rt-boost happens."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); @@ -131,12 +132,12 @@ static void torture_lock_busted_write_unlock(int tid __maybe_unused) static void __torture_rt_boost(struct torture_random_state *trsp) { - const unsigned int factor = 50000; /* yes, quite arbitrary */ + const unsigned int factor = rt_boost_factor; if (!rt_task(current)) { /* - * Boost priority once every ~50k operations. When the - * task tries to take the lock, the rtmutex it will account + * Boost priority once every 'rt_boost_factor' operations. When + * the task tries to take the lock, the rtmutex it will account * for the new priority, and do any corresponding pi-dance. */ if (trsp && !(torture_random(trsp) % @@ -146,8 +147,9 @@ static void __torture_rt_boost(struct torture_random_state *trsp) return; } else { /* - * The task will remain boosted for another ~500k operations, - * then restored back to its original prio, and so forth. + * The task will remain boosted for another 10 * 'rt_boost_factor' + * operations, then restored back to its original prio, and so + * forth. * * When @trsp is nil, we want to force-reset the task for * stopping the kthread.