linux-kernel - Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory barrier (v3a)

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: <1263244757.4244.75.camel@laptop>
Date:	Mon, 11 Jan 2010 22:19:17 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Cc:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Oleg Nesterov <oleg@...hat.com>, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...e.hu>, akpm@...ux-foundation.org,
	josh@...htriplett.org, tglx@...utronix.de, Valdis.Kletnieks@...edu,
	dhowells@...hat.com, laijs@...fujitsu.com, dipankar@...ibm.com,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory
 barrier (v3a)

On Mon, 2010-01-11 at 15:52 -0500, Mathieu Desnoyers wrote:
> 
> So the clear bit can occur far, far away in the future, we don't care.
> We'll just send extra IPIs when unneeded in this time-frame.

I think we should try harder not to disturb CPUs, particularly in the
face of RT tasks and DoS scenarios. Therefore I don't think we should
just wildly send to mm_cpumask(), but verify (although speculatively)
that the remote tasks' mm matches ours.



--
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/