linux-kernel - Re: performance differences: "maxcpus=1" vs. "echo 0

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]

Date:	Tue, 25 Mar 2008 17:38:15 +0100 (CET)
From:	Michael Meyer <mike65134@...oo.de>
To:	linux-kernel@...r.kernel.org
Subject: Re: performance differences: "maxcpus=1" vs. "echo 0 > /sys/devices/system/cpu/cpu1/online"


--- Luciano Rocha <luciano@...otux.com> schrieb:

> 
> On Tue, Mar 25, 2008 at 02:47:50PM +0100, Michael
> Meyer wrote:
> > Hi, 
> > 
> > what is the difference between booting a dual core
> > machine with "maxcpus=1" or by deactivating the
> second
> > core at run time with "echo 0 >
> > /sys/devices/system/cpu/cpu1/online"?
> 
> maxcpus=1 should turn off the SMP alternative and
> switch to UP only,
> optimising some locks and instructions.

Can this be achieved during runtime also? And is it
possible to switch back to SMP after that?


      Lesen Sie Ihre E-Mails jetzt einfach von unterwegs.
www.yahoo.de/go

--
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/