linux-kernel - Re: [RFCv2][PATCH] flexible array implementation

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: <4A67CEB7.2080505@zytor.com>
Date:	Wed, 22 Jul 2009 19:45:11 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Dave Hansen <dave@...ux.vnet.ibm.com>
CC:	akpm@...ux-foundation.org, containers@...ts.linux-foundation.org,
	bblum@...gle.com, linux-kernel@...r.kernel.org, menage@...gle.com,
	vda.linux@...glemail.com, mikew@...gle.com
Subject: Re: [RFCv2][PATCH] flexible array implementation

On 07/21/2009 03:00 PM, Dave Hansen wrote:
> 
> Here's an alternative.  I think it's what Andrew was
> suggesting  here:
> 
> 	http://lkml.org/lkml/2009/7/2/518 
> 
> I call it a flexible array.  It does all of its work in
> PAGE_SIZE bits, so never does an order>0 allocation.
> The base level has PAGE_SIZE-2*sizeof(int) bytes of
> storage for pointers to the second level.  So, with a
> 32-bit arch, you get about 4MB (4183112 bytes) of total
> storage when the objects pack nicely into a page.  It
> is half that on 64-bit because the pointers are twice
> the size.
> 

I'm wondering if there is any use case which would require scaling below
the PAGE_SIZE level... in which case it would be nice for it to
gracefully decay to a single kmalloc allocation + some metadata.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
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/