linux-kernel - Re: [PATCH -v4 1/2] lib, Make gen

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:	Wed, 17 Nov 2010 12:38:56 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	huang ying <huang.ying.caritas@...il.com>
Cc:	Huang Ying <ying.huang@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Len Brown <lenb@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>,
	Mauro Carvalho Chehab <mchehab@...hat.com>,
	Steven Rostedt <rostedt@...dmis.org>
Subject: Re: [PATCH -v4 1/2] lib, Make gen_pool memory allocator lockless

On Wed, 2010-11-17 at 19:16 +0800, huang ying wrote:
> > I'm not sure Andrew's CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG makes much sense
> > for CONFIG_ARCH_HAVE_NMI=n though..
> 
> Sorry, I do not find ARCH_HAVE_NMI in any Kconfig, can you help me to
> point out? I think cmpxchg can be used safely in lock-less code on
> architectures without NMI. 

It doesn't exist, but what I'm saying is that HAVE_NMI_SAFE_CMPXCHG is
pointless for architectures that don't actually have an NMI, although I
guess you can argue that since it doesn't have one its safe by default,
still slightly confusing.

Some arch don't currently implement NMI like functionality (ARM comes to
mind) but they could using interrupt priorities (like SPARC64 does for
example).


--
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/