Messages in this thread Patch in this message | | | Date | Wed, 22 Apr 2020 09:16:47 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 23/23] sched: Remove sched_set_*() return value |
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On Wed, Apr 22, 2020 at 01:27:42PM +0200, Peter Zijlstra wrote: > Ingo suggested that since the new sched_set_*() functions are > implemented using the 'nocheck' variants, they really shouldn't ever > fail, so remove the return value. > > Cc: axboe@kernel.dk > Cc: daniel.lezcano@linaro.org > Cc: sudeep.holla@arm.com > Cc: airlied@redhat.com > Cc: broonie@kernel.org > Cc: paulmck@kernel.org > Suggested-by: Ingo Molnar <mingo@kernel.org> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > drivers/block/drbd/drbd_receiver.c | 4 +--- > drivers/firmware/psci/psci_checker.c | 3 +-- > drivers/gpu/drm/msm/msm_drv.c | 5 +---- > drivers/platform/chrome/cros_ec_spi.c | 7 +++---- > include/linux/sched.h | 6 +++--- > kernel/rcu/rcutorture.c | 5 +---- > kernel/sched/core.c | 12 ++++++------ > 7 files changed, 16 insertions(+), 26 deletions(-)
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> --- a/kernel/rcu/rcutorture.c > +++ b/kernel/rcu/rcutorture.c > @@ -806,10 +806,7 @@ static int rcu_torture_boost(void *arg) > VERBOSE_TOROUT_STRING("rcu_torture_boost started"); > > /* Set real-time priority. */ > - if (sched_set_fifo_low(current) < 0) { > - VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); > - n_rcu_torture_boost_rterror++; > - } > + sched_set_fifo_low(current); > > init_rcu_head_on_stack(&rbi.rcu); > /* Each pass through the following loop does one boost-test cycle. */
This is the only update of n_rcu_torture_boost_rterror, so it can be eliminated entirely, for example as shown below.
Other than that, looks good to me!
Thanx, Paul
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diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index ee27b57..61b0c4f 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -171,7 +171,6 @@ static atomic_t n_rcu_torture_mberror; static atomic_t n_rcu_torture_error; static long n_rcu_torture_barrier_error; static long n_rcu_torture_boost_ktrerror; -static long n_rcu_torture_boost_rterror; static long n_rcu_torture_boost_failure; static long n_rcu_torture_boosts; static atomic_long_t n_rcu_torture_timers; @@ -893,10 +892,7 @@ static int rcu_torture_boost(void *arg) VERBOSE_TOROUT_STRING("rcu_torture_boost started"); /* Set real-time priority. */ - if (sched_set_fifo_low(current) < 0) { - VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); - n_rcu_torture_boost_rterror++; - } + sched_set_fifo_low(current); init_rcu_head_on_stack(&rbi.rcu); /* Each pass through the following loop does one boost-test cycle. */ @@ -1527,11 +1523,10 @@ rcu_torture_stats_print(void) atomic_read(&n_rcu_torture_alloc), atomic_read(&n_rcu_torture_alloc_fail), atomic_read(&n_rcu_torture_free)); - pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ", + pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld ", atomic_read(&n_rcu_torture_mberror), n_rcu_torture_barrier_error, - n_rcu_torture_boost_ktrerror, - n_rcu_torture_boost_rterror); + n_rcu_torture_boost_ktrerror); pr_cont("rtbf: %ld rtb: %ld nt: %ld ", n_rcu_torture_boost_failure, n_rcu_torture_boosts, @@ -1545,14 +1540,12 @@ rcu_torture_stats_print(void) pr_alert("%s%s ", torture_type, TORTURE_FLAG); if (atomic_read(&n_rcu_torture_mberror) || n_rcu_torture_barrier_error || n_rcu_torture_boost_ktrerror || - n_rcu_torture_boost_rterror || n_rcu_torture_boost_failure || - i > 1) { + n_rcu_torture_boost_failure || i > 1) { pr_cont("%s", "!!! "); atomic_inc(&n_rcu_torture_error); WARN_ON_ONCE(atomic_read(&n_rcu_torture_mberror)); WARN_ON_ONCE(n_rcu_torture_barrier_error); // rcu_barrier() WARN_ON_ONCE(n_rcu_torture_boost_ktrerror); // no boost kthread - WARN_ON_ONCE(n_rcu_torture_boost_rterror); // can't set RT prio WARN_ON_ONCE(n_rcu_torture_boost_failure); // RCU boost failed WARN_ON_ONCE(i > 1); // Too-short grace period } @@ -2569,7 +2562,6 @@ rcu_torture_init(void) atomic_set(&n_rcu_torture_error, 0); n_rcu_torture_barrier_error = 0; n_rcu_torture_boost_ktrerror = 0; - n_rcu_torture_boost_rterror = 0; n_rcu_torture_boost_failure = 0; n_rcu_torture_boosts = 0; for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
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