linux-kernel - Re: [mm][RFC][PATCH 0/11] mm accessor updates.

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: <4B2BB52A.7050103@redhat.com>
Date:	Fri, 18 Dec 2009 19:00:26 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Christoph Lameter <cl@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andi Kleen <andi@...stfloor.org>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
	minchan.kim@...il.com
Subject: Re: [mm][RFC][PATCH 0/11] mm accessor updates.

On 12/18/2009 07:17 AM, Ingo Molnar wrote:
>
>> It is not about naming. The accessors hide the locking mechanism for
>> mmap_sem. Then you can change the locking in a central place.
>>
>> The locking may even become configurable later. Maybe an embedded solution
>> will want the existing scheme but dual quad socket may want a distributed
>> reference counter to avoid bouncing cachelines on faults.
>>      
> Hiding the locking is pretty much the worst design decision one can make.
>
>    

It does allow incremental updates.  For example if we go with range 
locks, the accessor turns into a range lock of the entire address space; 
users can be converted one by one to use their true ranges in order of 
importance.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

--
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/