linux-kernel - Re: [patch 2/5] sparse-vmemmap: specify vmemmap population range in bytes

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

Message-Id: <20130320.144341.680730923044605208.davem@davemloft.net>
Date:	Wed, 20 Mar 2013 14:43:41 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	hannes@...xchg.org
Cc:	x86@...nel.org, akpm@...ux-foundation.org, ben@...adent.org.uk,
	linux-mm@...ck.org, linux-arch@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [patch 2/5] sparse-vmemmap: specify vmemmap population range
 in bytes

From: Johannes Weiner <hannes@...xchg.org>
Date: Wed, 20 Mar 2013 14:03:29 -0400

> The sparse code, when asking the architecture to populate the vmemmap,
> specifies the section range as a starting page and a number of pages.
> 
> This is an awkward interface, because none of the arch-specific code
> actually thinks of the range in terms of 'struct page' units and
> always translates it to bytes first.
> 
> In addition, later patches mix huge page and regular page backing for
> the vmemmap.  For this, they need to call vmemmap_populate_basepages()
> on sub-section ranges with PAGE_SIZE and PMD_SIZE in mind.  But these
> are not necessarily multiples of the 'struct page' size and so this
> unit is too coarse.
> 
> Just translate the section range into bytes once in the generic sparse
> code, then pass byte ranges down the stack.
> 
> Signed-off-by: Johannes Weiner <hannes@...xchg.org>

Boot tested on sparc64:

Acked-by: David S. Miller <davem@...emloft.net>
--
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/