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  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:	Thu, 06 Dec 2007 10:27:09 -0800
From:	Roland Dreier <>
To:	Arnd Bergmann <>
Cc:, Joachim Fenkes <>,
	LKML <>,
	"OF-General" <>,
	Roland Dreier <>,
	"OF-EWG" <>,
	Stefan Roscher <>,
	Christoph Raisch <>,
	Marcus Eder <>
Subject: Re: [PATCH] IB/ehca: Serialize HCA-related hCalls on POWER5

 > > +               ehca_lock_hcalls = !(cur_cpu_spec->cpu_user_features
 > > +                                    & PPC_FEATURE_ARCH_2_05);

 > We already talked about this yesterday, but I still feel that checking the
 > instruction set of the CPU should not be used to determine whether a
 > specific device driver implementation is used int hypervisor.

I had the same reaction... is testing cpu_user_features really the
best way to detect this issue?

I'll hold off applying this for a few days so you guys can decide the
best thing to do.  We'll definitely get some fix into 2.6.24 but we
have time to make a good decision.

 > Regarding the performance problem, have you checked whether converting all
 > your spin_lock_irqsave to spin_lock/spin_lock_irq improves your performance
 > on the older machines? Maybe it's already fast enough that way.

It does seem that the only places that the hcall_lock is taken also
use msleep, so they must always be in process context.  So you can
safely just use spin_lock(), right?

 - R.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists