linux-kernel - Re: PATCH: Allow over-ride of smp_found

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: <20090206193121.GA32634@elte.hu>
Date:	Fri, 6 Feb 2009 20:31:21 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Ben Greear <greearb@...delatech.com>,
	Thomas Gleixner <tglx@...utronix.de>
Cc:	linux-kernel <linux-kernel@...r.kernel.org>, len.brown@...el.com
Subject: Re: PATCH:  Allow over-ride of smp_found_cfg with kernel cmd-line
	option.


* Ben Greear <greearb@...delatech.com> wrote:

> Allow user to keep smp_found_cfg set to 1 even if MADT
> cannot be parsed.  This works around funky BIOS on FWA-7304
> (VIA CN700 chipset) system, and possibly other systems as well.
> Without this override, performance drops by around 15% on
> network throughput tests on this system.

The question is, _why_ does network performance drop?

Do you have a before/after pair of /proc/interrupts output
perhaps? Does the layout of IRQs change?

The system is not SMP - so only something about UP-IOAPIC can
be helpful to performance here - or some unknown effect.

	Ingo
--
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/