linux-kernel - Re: sched: hang in migrate

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: <20140225104924.GK9987@twins.programming.kicks-ass.net>
Date:	Tue, 25 Feb 2014 11:49:24 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Michael wang <wangyun@...ux.vnet.ibm.com>
Cc:	Sasha Levin <sasha.levin@...cle.com>,
	Ingo Molnar <mingo@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: sched: hang in migrate_swap

On Tue, Feb 25, 2014 at 12:47:01PM +0800, Michael wang wrote:
> On 02/24/2014 09:10 PM, Peter Zijlstra wrote:
> > On Mon, Feb 24, 2014 at 01:12:18PM +0100, Peter Zijlstra wrote:
> >> +		if (p) {
> >> +			if (unlikely(p == RETRY_TASK))
> >> +				goto again;
> > 
> > We could even make that: unlikely(p & 1), I think most CPUs can encode
> > that far better than the full pointer immediate.
> 
> Agree, unless odd-align stuff appeared...

That shouldn't happen; we rely on u32 alignment all over the place. So
for general objects we should have at least the lower two bits free to
play with.
--
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/