linux-kernel - Re: linux-next: build failure after merge of the tip tree

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]

Message-ID: <20140120110658.GZ31570@twins.programming.kicks-ass.net>
Date:	Mon, 20 Jan 2014 12:06:58 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Len Brown <lenb@...nel.org>,
	Stephen Rothwell <sfr@...b.auug.org.au>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...e.hu>, linux-next@...r.kernel.org,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: linux-next: build failure after merge of the tip tree

On Mon, Jan 20, 2014 at 02:19:30AM -0800, H. Peter Anvin wrote:
> On 01/20/2014 02:13 AM, Peter Zijlstra wrote:
> > On Mon, Jan 20, 2014 at 09:30:21AM +0100, Peter Zijlstra wrote:
> >> Then make them so. The fact was that most of the mwait idle sites
> >> were bloody broken. And the single mwait_idle_with_hints() function
> >> presents a single nice function that does all the required magics.
> > 
> > To stress this a bit more; have a look see at mwwait_idle_with_hints();
> > it does a whole lot of subtle magic.
> > 
> >  - current_{set,clr}_polling*(), these are crucial in not missing and
> >    wrecking NEED_RESCHED state.
> > 
> >  - X86_FEATURE_CLFLUSH_MONTIOR quirk
> > 
> >  - Does the monitor(); if (!need_resched()) mwait() thing.
> > 
> > All of those are required for a correct and functional idle loop. And
> > I've seen sites where any or all of the above were missing/broken.
> > 
> > Not unifying the lot into a simple usable function is just stupid --
> > history has shown people simply cannot be trusted to get this right.
> > 
> 
> I don't think anyone is arguing that.  The question is rather if the
> implementation is correct, and if it is ready for the merge window.

I've yet to hear an argument against it other than vaguaries.
--
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/