linux-kernel - Re: [RFC 4/8] Enhance fallback functions in libs to support higher order pages

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: <20070419225011.GK32602149@melbourne.sgi.com>
Date:	Fri, 20 Apr 2007 08:50:12 +1000
From:	David Chinner <dgc@....com>
To:	Christoph Lameter <clameter@....com>
Cc:	Adam Litke <aglitke@...il.com>, linux-kernel@...r.kernel.org,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Nick Piggin <nickpiggin@...oo.com.au>, Andi Kleen <ak@...e.de>,
	Paul Jackson <pj@....com>, Dave Chinner <dgc@....com>
Subject: Re: [RFC 4/8] Enhance fallback functions in libs to support higher order pages

On Thu, Apr 19, 2007 at 12:10:34PM -0700, Christoph Lameter wrote:
> Variable Order Page Cache: Add functions to establish sizes
> 
> We use the macros PAGE_CACHE_SIZE PAGE_CACHE_SHIFT PAGE_CACHE_MASK
> and PAGE_CACHE_ALIGN in various places in the kernel. These are now
> the base page size but we do not have a means to calculating these
> values for higher order pages.
> 
> Provide these functions. An address_space pointer must be passed
> to them.
> 
> New function			Related base page constant
> ---------------------------------------------------
> page_cache_shift(a)		PAGE_CACHE_SHIFT
> page_cache_size(a)		PAGE_CACHE_SIZE
> page_cache_mask(a)		PAGE_CACHE_MASK
> page_cache_align(addr,a)	PAGE_CACHE_ALIGN(addr)

I think PAGE_CACHE_SIZE is a redundant define with these
modifications.  The page cache size in now variable and it is based
on a multiple of PAGE_SIZE. Hence I suggest that PAGE_CACHE_SIZE and
it's derivitives should be made to go away completely with this
change.

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group
-
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/