linux-kernel - Re: [PATCH] adjust root-domain->online span in response to hotplug event

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: <20080309023515.GC15909@linux-os.sc.intel.com>
Date:	Sat, 8 Mar 2008 18:35:15 -0800
From:	Suresh Siddha <suresh.b.siddha@...el.com>
To:	Gregory Haskins <ghaskins@...ell.com>
Cc:	suresh.b.siddha@...el.com, rjw@...k.pl, akpm@...ux-foundation.org,
	dmitry.adamushko@...il.com, ego@...ibm.com, mingo@...e.hu,
	oleg@...sign.ru, yi.y.yang@...el.com, linux-kernel@...r.kernel.org,
	tglx@...utronix.de
Subject: Re: [PATCH] adjust root-domain->online span in response to hotplug event

On Sat, Mar 08, 2008 at 12:10:15AM -0500, Gregory Haskins wrote:
> Suresh Siddha wrote:
>  >
>  > -	cpus_and(*lowest_mask, task_rq(task)->rd->online, task->cpus_allowed);
>  > +	cpus_and(*lowest_mask, task->cpus_allowed, cpu_online_map);
> 
> Hi Suresh,
>    Unfortunately, this patch will introduce its own set of bugs. 

Is that because of the missing get/put_online_cpus() ?

> However, your analysis was spot-on.  I think I see the problem now.  It 
> was introduced when I put a hack in to "fix" s2ram problems in -mm as a 
> result of the new root-domain logic.  I think the following patch will 
> fix both issues:

BTW, what is use of per root domains online map, when we have global
cpu_online_map() ? Each domains span & cpu_online_map should give
domain_online_map anyhow.

And is n't it buggy if someone accesses rd->online with out get/put_online_map()

thanks,
suresh
--
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/