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]
Date:	Wed, 2 Aug 2006 00:46:39 -0400
From:	Dave Jones <davej@...hat.com>
To:	Andi Kleen <ak@...e.de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: frequent slab corruption (since a long time)

On Wed, Aug 02, 2006 at 06:35:00AM +0200, Andi Kleen wrote:
 > On Wednesday 02 August 2006 06:22, Dave Jones wrote:
 > 
 > > Problem with that approach is that DEBUG_PAGEALLOC makes things
 > > so damned slow that it's pretty much unusable, and this bug
 > > doesn't seem to want to repeat itself to order, so I doubt
 > > many people would put up with the slowdown long enough to chase it down.
 > 
 > Really?  It shouldn't be that much slower in theory. Do you
 > have numbers?

You need slower boxes :-)

Every time I enable it to try and diagnose a bug in the Fedora kernel
I get a flood of "hey what gives, everything got slow" emails.
That speaks louder than any numbers to me.

It could be less of an issue on modern CPUs than it used to be, but
it has been painful enough in the past that I've really only enabled
it when I've been desperately trying to chase something down.

 > If it's a big problem it could probably be made faster by batching
 > the TLB flushes more.

Maybe, though that gives me the creeps a little for some reason.

		Dave

-- 
http://www.codemonkey.org.uk
-
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ