linux-kernel - Re: [PATCH v7 3/6] MCS Lock: Move mcs_lock/unlock function into its own file

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] [day] [month] [year] [list]

Message-ID: <20140120121547.GC31570@twins.programming.kicks-ass.net>
Date:	Mon, 20 Jan 2014 13:15:47 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Tim Chen <tim.c.chen@...ux.intel.com>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"Paul E.McKenney" <paulmck@...ux.vnet.ibm.com>,
	Will Deacon <will.deacon@....com>,
	linux-kernel@...r.kernel.org, linux-mm <linux-mm@...ck.org>,
	linux-arch@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Waiman Long <waiman.long@...com>,
	Andrea Arcangeli <aarcange@...hat.com>,
	Alex Shi <alex.shi@...aro.org>,
	Andi Kleen <andi@...stfloor.org>,
	Michel Lespinasse <walken@...gle.com>,
	Davidlohr Bueso <davidlohr.bueso@...com>,
	Matthew R Wilcox <matthew.r.wilcox@...el.com>,
	Dave Hansen <dave.hansen@...el.com>,
	Rik van Riel <riel@...hat.com>,
	Peter Hurley <peter@...leysoftware.com>,
	Raghavendra K T <raghavendra.kt@...ux.vnet.ibm.com>,
	George Spelvin <linux@...izon.com>,
	"H. Peter Anvin" <hpa@...or.com>, Arnd Bergmann <arnd@...db.de>,
	Aswin Chandramouleeswaran <aswin@...com>,
	Scott J Norton <scott.norton@...com>,
	"Figo.zhang" <figo1802@...il.com>
Subject: Re: [PATCH v7 3/6] MCS Lock: Move mcs_lock/unlock function into its
 own file

On Thu, Jan 16, 2014 at 04:08:24PM -0800, Tim Chen wrote:
> copy to kernel/locking/mcs_spinlock.c
> index 96f14299..44fb092 100644
> --- a/include/linux/mcs_spinlock.h
> +++ b/kernel/locking/mcs_spinlock.c
> +/*
> + * asm/processor.h may define arch_mutex_cpu_relax().
> + * If it is not defined, cpu_relax() will be used.
> + */
> +#include <asm/barrier.h>
> +#include <asm/cmpxchg.h>
> +#include <asm/processor.h>
> +#include <linux/compiler.h>
> +#include <linux/mcs_spinlock.h>
> +#include <linux/export.h>
>  
> +#ifndef arch_mutex_cpu_relax
> +# define arch_mutex_cpu_relax() cpu_relax()
> +#endif

Why not include <linux/mutex.h> to obtain arch_mutex_cpu_relax() ?

Now you have duplicated the definition, and in a file unrelated to its
name 'mutex'.

Now, arguable, we should maybe look at renaming the thing now that its
used outside of mutices, but whatever we do, I think its sane to keep a
single 'generic' definition.
--
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/