linux-kernel - Re: [patch 00/21] high resolution timers / dynamic ticks

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: <20061003084729.GA24961@elte.hu>
Date:	Tue, 3 Oct 2006 10:47:29 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Andrew Morton <akpm@...l.org>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	LKML <linux-kernel@...r.kernel.org>, Jim Gettys <jg@...top.org>,
	John Stultz <johnstul@...ibm.com>,
	David Woodhouse <dwmw2@...radead.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Dave Jones <davej@...hat.com>
Subject: Re: [patch 00/21] high resolution timers / dynamic ticks - V2


* Andrew Morton <akpm@...l.org> wrote:

> These patches make my Vaio run really really slowly.  Maybe a quarter 
> of the normal speed or lower.  Bisection shows that the bug is 
> introduced by 
> clockevents-drivers-for-i386.patch+clockevents-drivers-for-i386-fix.patch
> 
> With all patches applied, the slowdown happens with 
> CONFIG_HIGH_RES_TIMERS=n and also with CONFIG_HIGH_RES_TIMERS=y && 
> CONFIG_NO_HZ=y.  So something got collaterally damaged.

yeah, i suspect it works again if you disable:

 CONFIG_X86_UP_APIC=y
 CONFIG_X86_UP_IOAPIC=y
 CONFIG_X86_LOCAL_APIC=y
 CONFIG_X86_IO_APIC=y

as the slowdown has the feeling of a runaway lapic timer irq.

from code review so far we can only see an udelay(10) difference in the 
initialization sequence of the PIT - we'll send a fix for that but i 
dont think that's the cause of the bug.

investigating it.

	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/