linux-kernel - RE: [PATCH v3] rcutorture: Create nocb tasks only for CONFIG_RCU_NOCB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <PH0PR11MB5880EE5E5653216772BF1047DAD79@PH0PR11MB5880.namprd11.prod.outlook.com>
Date:   Fri, 3 Feb 2023 06:38:07 +0000
From:   "Zhang, Qiang1" <qiang1.zhang@...el.com>
To:     "Zhang, Qiang1" <qiang1.zhang@...el.com>,
        "paulmck@...nel.org" <paulmck@...nel.org>,
        "frederic@...nel.org" <frederic@...nel.org>,
        "quic_neeraju@...cinc.com" <quic_neeraju@...cinc.com>,
        "joel@...lfernandes.org" <joel@...lfernandes.org>
CC:     "rcu@...r.kernel.org" <rcu@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v3] rcutorture: Create nocb tasks only for
 CONFIG_RCU_NOCB_CPU=y kernels

>When setting nocbs_nthreads to start rcutorture test with a non-zero value,
>the nocb tasks will be created and invoke rcu_nocb_cpu_offload/deoffload()
>to toggle CPU's callback-offload state, but for CONFIG_RCU_NOCB_CPU=n
>kernel, the rcu_nocb_cpu_offload/deoffload() is a no-op and this is also
>meaningless for torture_type is non-rcu.
>
>This commit therefore add member can_nocbs_toggle to rcu_torture_ops
>structure to avoid unnecessary nocb tasks creation.

Will change commit log next version.

Thanks
Zqiang

>
>Signed-off-by: Zqiang <qiang1.zhang@...el.com>
>---
> kernel/rcu/rcutorture.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
>index 297da28ce92d..d01127e0e8cd 100644
>--- a/kernel/rcu/rcutorture.c
>+++ b/kernel/rcu/rcutorture.c
>@@ -3708,6 +3708,12 @@ rcu_torture_init(void)
> 		pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
> 		fqs_duration = 0;
> 	}
>+	if (nocbs_nthreads != 0 && (cur_ops != &rcu_ops ||
>+					!IS_ENABLED(CONFIG_RCU_NOCB_CPU))) {
>+		pr_alert("rcu-torture types: %s and CONFIG_RCU_NOCB_CPU=%d, nocb toggle disabled.\n",
>+				cur_ops->name, IS_ENABLED(CONFIG_RCU_NOCB_CPU));
>+		nocbs_nthreads = 0;
>+	}
> 	if (cur_ops->init)
> 		cur_ops->init();
> 
>-- 
>2.25.1