From 93898fb1a395d2a5a53db238c68036da2f8c64d1 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 17 Aug 2011 12:39:34 -0700 Subject: [PATCH] rcu: Make rcu_torture_fqs() exit loops at end of test The rcu_torture_fqs() function can prevent the rcutorture tests from completing, resulting in a hang. This commit therefore ensures that rcu_torture_fqs() will exit its inner loops at the end of the test, and also applies the newish ULONG_CMP_LT() macro to time comparisons. Signed-off-by: Paul E. McKenney --- kernel/rcutorture.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index ade7771b208a..2431d576e9ca 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -741,7 +741,7 @@ static int rcu_torture_boost(void *arg) do { /* Wait for the next test interval. */ oldstarttime = boost_starttime; - while (jiffies - oldstarttime > ULONG_MAX / 2) { + while (ULONG_CMP_LT(jiffies, oldstarttime)) { schedule_timeout_uninterruptible(1); rcu_stutter_wait("rcu_torture_boost"); if (kthread_should_stop() || @@ -752,7 +752,7 @@ static int rcu_torture_boost(void *arg) /* Do one boost-test interval. */ endtime = oldstarttime + test_boost_duration * HZ; call_rcu_time = jiffies; - while (jiffies - endtime > ULONG_MAX / 2) { + while (ULONG_CMP_LT(jiffies, endtime)) { /* If we don't have a callback in flight, post one. */ if (!rbi.inflight) { smp_mb(); /* RCU core before ->inflight = 1. */ @@ -818,11 +818,13 @@ rcu_torture_fqs(void *arg) VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); do { fqs_resume_time = jiffies + fqs_stutter * HZ; - while (jiffies - fqs_resume_time > LONG_MAX) { + while (ULONG_CMP_LT(jiffies, fqs_resume_time) && + !kthread_should_stop()) { schedule_timeout_interruptible(1); } fqs_burst_remaining = fqs_duration; - while (fqs_burst_remaining > 0) { + while (fqs_burst_remaining > 0 && + !kthread_should_stop()) { cur_ops->fqs(); udelay(fqs_holdoff); fqs_burst_remaining -= fqs_holdoff;