linux-kernel - Re: [PATCH 1/1] hotplug cpu: migrate a task within its cpuset

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: <20070825111828.GA246@tv-sign.ru>
Date:	Sat, 25 Aug 2007 15:18:28 +0400
From:	Oleg Nesterov <oleg@...sign.ru>
To:	Cliff Wickman <cpw@....com>
Cc:	akpm@...ux-foundation.org, ego@...ibm.com, mingo@...e.hu,
	vatsa@...ibm.com, pj@....com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] hotplug cpu: migrate a task within its cpuset

On 08/24, Cliff Wickman wrote:
> 
> @@ -5091,6 +5092,17 @@ restart:
>  	if (dest_cpu == NR_CPUS)
>  		dest_cpu = any_online_cpu(p->cpus_allowed);
>  
> +	/* try to stay on the same cpuset */
> +	if (dest_cpu == NR_CPUS) {
> +		/*
> +		 * The cpuset_cpus_allowed_lock() variant of
> +		 * cpuset_cpus_allowed() will not block
> +		 * It must be called within calls to cpuset_lock/cpuset_unlock.
> +		 */
> +		p->cpus_allowed = cpuset_cpus_allowed_lock(p);
> +		dest_cpu = any_online_cpu(p->cpus_allowed);

Ugh, didn't notice while reading this patch.

We shouldn't change ->cpus_allowed without rq->lock. Please look what
the current code does in "/* No more Mr. Nice Guy. */" case.

Oleg.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/