linux-kernel - Re: [PATCH] rudimentary tracing for Classic RCU

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: <20081009115041.GC6628@linux.vnet.ibm.com>
Date:	Thu, 9 Oct 2008 04:50:41 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Lai Jiangshan <laijs@...fujitsu.com>, linux-kernel@...r.kernel.org,
	mingo@...e.hu, rjw@...k.pl, dipankar@...ibm.com,
	tglx@...uxtronix.de
Subject: Re: [PATCH] rudimentary tracing for Classic RCU

On Thu, Oct 09, 2008 at 08:55:29AM +0200, Andi Kleen wrote:
> > In this case, why not define it as:
> > static char buf[20*NR_CPUS + 100];
> 
> Actually you should near never use NR_CPUS now but always num_possible_cpus()
> (or even num_online_cpus()) Using NR_CPUS can lead to extreme waste
> of memory on kernels which are compiled for 4096 CPUs for example.
> 
> And with num_possible_cpus() kmalloc is needed.

OK, new one on me!  Thank you for the pointer!

							Thanx, Paul
--
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/