From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756498AbcHVT4T (ORCPT ); Mon, 22 Aug 2016 15:56:19 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:57679 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756113AbcHVT4R (ORCPT ); Mon, 22 Aug 2016 15:56:17 -0400 X-IBM-Helo: d03dlp02.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 1/5] torture: Convert torture_shutdown() to hrtimer Date: Mon, 22 Aug 2016 08:54:42 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20160822155423.GA11367@linux.vnet.ibm.com> References: <20160822155423.GA11367@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16082215-0024-0000-0000-000014619DE8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005629; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000183; SDB=6.00748126; UDB=6.00353040; IPR=6.00520792; BA=6.00004672; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012420; XFM=3.00000011; UTC=2016-08-22 15:54:40 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16082215-0025-0000-0000-000043C7C0FD Message-Id: <1471881286-12605-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-08-22_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608220165 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Upcoming changes to the timer wheel introduce significant inaccuracy and possibly also an ultimate limit on timeout duration. This is a problem for the current implementation of torture_shutdown() because (1) shutdown times are user-specified, and can therefore be quite long, and (2) the torture scripting will kill a test instance that runs for more than a few minutes longer than scheduled. This commit therefore converts the torture_shutdown() timed waits to an hrtimer. Signed-off-by: Paul E. McKenney Acked-by: Arnd Bergmann --- kernel/torture.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) diff --git a/kernel/torture.c b/kernel/torture.c index 75961b3decfe..0d887eb62856 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -446,9 +447,8 @@ EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); * Variables for auto-shutdown. This allows "lights out" torture runs * to be fully scripted. */ -static int shutdown_secs; /* desired test duration in seconds. */ static struct task_struct *shutdown_task; -static unsigned long shutdown_time; /* jiffies to system shutdown. */ +static ktime_t shutdown_time; /* time to system shutdown. */ static void (*torture_shutdown_hook)(void); /* @@ -471,20 +471,20 @@ EXPORT_SYMBOL_GPL(torture_shutdown_absorb); */ static int torture_shutdown(void *arg) { - long delta; - unsigned long jiffies_snap; + ktime_t ktime_snap; VERBOSE_TOROUT_STRING("torture_shutdown task started"); - jiffies_snap = jiffies; - while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && + ktime_snap = ktime_get(); + while (ktime_before(ktime_snap, shutdown_time) && !torture_must_stop()) { - delta = shutdown_time - jiffies_snap; if (verbose) pr_alert("%s" TORTURE_FLAG - "torture_shutdown task: %lu jiffies remaining\n", - torture_type, delta); - schedule_timeout_interruptible(delta); - jiffies_snap = jiffies; + "torture_shutdown task: %llu ms remaining\n", + torture_type, + ktime_ms_delta(shutdown_time, ktime_snap)); + set_current_state(TASK_INTERRUPTIBLE); + schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); + ktime_snap = ktime_get(); } if (torture_must_stop()) { torture_kthread_stopping("torture_shutdown"); @@ -511,10 +511,9 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void)) { int ret = 0; - shutdown_secs = ssecs; torture_shutdown_hook = cleanup; - if (shutdown_secs > 0) { - shutdown_time = jiffies + shutdown_secs * HZ; + if (ssecs > 0) { + shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); ret = torture_create_kthread(torture_shutdown, NULL, shutdown_task); } -- 2.5.2