linux-kernel - Re: [PATCH] cpu/hotplug: wait for cpuset_hotplug

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <YBvCYhdPai+pb8u2@hirez.programming.kicks-ass.net>
Date:   Thu, 4 Feb 2021 10:46:10 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Alexey Klimov <aklimov@...hat.com>
Cc:     linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
        yury.norov@...il.com, daniel.m.jordan@...cle.com,
        tglx@...utronix.de, jobaker@...hat.com, audralmitchel@...il.com,
        arnd@...db.de, gregkh@...uxfoundation.org, rafael@...nel.org,
        tj@...nel.org, lizefan@...wei.com, qais.yousef@....com,
        hannes@...xchg.org, klimov.linux@...il.com
Subject: Re: [PATCH] cpu/hotplug: wait for cpuset_hotplug_work to finish on
 cpu onlining

On Thu, Feb 04, 2021 at 01:01:57AM +0000, Alexey Klimov wrote:
> @@ -1281,6 +1282,11 @@ static int cpu_up(unsigned int cpu, enum cpuhp_state target)
>  	err = _cpu_up(cpu, 0, target);
>  out:
>  	cpu_maps_update_done();
> +
> +	/* To avoid out of line uevent */
> +	if (!err)
> +		cpuset_wait_for_hotplug();
> +
>  	return err;
>  }
>  

> @@ -2071,14 +2075,18 @@ static void cpuhp_online_cpu_device(unsigned int cpu)
>  	struct device *dev = get_cpu_device(cpu);
>  
>  	dev->offline = false;
> -	/* Tell user space about the state change */
> -	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
>  }
>  

One concequence of this is that you'll now get a bunch of notifications
across things like suspend/hybernate.