Messages in this thread Patch in this message | | | Date | Wed, 27 Nov 2019 13:47:25 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH v2 12/14] torture: Replace cpu_up/down with device_online/offline |
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On Mon, Nov 25, 2019 at 11:27:52AM +0000, Qais Yousef wrote: > The core device API performs extra housekeeping bits that are missing > from directly calling cpu_up/down. > > See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and > serialization during LPM") for an example description of what might go > wrong. > > This also prepares to make cpu_up/down a private interface for anything > but the cpu subsystem. > > Signed-off-by: Qais Yousef <qais.yousef@arm.com> > CC: Davidlohr Bueso <dave@stgolabs.net> > CC: "Paul E. McKenney" <paulmck@kernel.org> > CC: Josh Triplett <josh@joshtriplett.org> > CC: linux-kernel@vger.kernel.org
Looks fine from an rcutorture viewpoint, but why not provide an API that pulled lock_device_hotplug() and unlock_device_hotplug() into the online/offline calls?
Thanx, Paul
> --- > kernel/torture.c | 15 +++++++++++---- > 1 file changed, 11 insertions(+), 4 deletions(-) > > diff --git a/kernel/torture.c b/kernel/torture.c > index 7c13f5558b71..12115024feb2 100644 > --- a/kernel/torture.c > +++ b/kernel/torture.c > @@ -97,7 +97,9 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, > torture_type, cpu); > starttime = jiffies; > (*n_offl_attempts)++; > - ret = cpu_down(cpu); > + lock_device_hotplug(); > + ret = device_offline(get_cpu_device(cpu)); > + unlock_device_hotplug(); > if (ret) { > if (verbose) > pr_alert("%s" TORTURE_FLAG > @@ -148,7 +150,9 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, > torture_type, cpu); > starttime = jiffies; > (*n_onl_attempts)++; > - ret = cpu_up(cpu); > + lock_device_hotplug(); > + ret = device_online(get_cpu_device(cpu)); > + unlock_device_hotplug(); > if (ret) { > if (verbose) > pr_alert("%s" TORTURE_FLAG > @@ -192,17 +196,20 @@ torture_onoff(void *arg) > for_each_online_cpu(cpu) > maxcpu = cpu; > WARN_ON(maxcpu < 0); > - if (!IS_MODULE(CONFIG_TORTURE_TEST)) > + if (!IS_MODULE(CONFIG_TORTURE_TEST)) { > + lock_device_hotplug(); > for_each_possible_cpu(cpu) { > if (cpu_online(cpu)) > continue; > - ret = cpu_up(cpu); > + ret = device_online(get_cpu_device(cpu)); > if (ret && verbose) { > pr_alert("%s" TORTURE_FLAG > "%s: Initial online %d: errno %d\n", > __func__, torture_type, cpu, ret); > } > } > + unlock_device_hotplug(); > + } > > if (maxcpu == 0) { > VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); > -- > 2.17.1 >
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