linux-kernel - Re: [patch 02/10] mm: bootmem: remove redundant offset check when finally freeing bootmem

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Message-ID: <20120507180828.GE19417@google.com>
Date:	Mon, 7 May 2012 11:08:28 -0700
From:	Tejun Heo <tj@...nel.org>
To:	Johannes Weiner <hannes@...xchg.org>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Gavin Shan <shangw@...ux.vnet.ibm.com>,
	David Miller <davem@...emloft.net>,
	Yinghai Lu <yinghai@...nel.org>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [patch 02/10] mm: bootmem: remove redundant offset check when
 finally freeing bootmem

On Mon, May 07, 2012 at 01:37:44PM +0200, Johannes Weiner wrote:
> When bootmem releases an unaligned BITS_PER_LONG pages chunk of memory
> to the page allocator, it checks the bitmap if there are still
> unreserved pages in the chunk (set bits), but also if the offset in
> the chunk indicates BITS_PER_LONG loop iterations already.
> 
> But since the consulted bitmap is only a one-word-excerpt of the full
> per-node bitmap, there can not be more than BITS_PER_LONG bits set in
> it.  The additional offset check is unnecessary.
> 
> Signed-off-by: Johannes Weiner <hannes@...xchg.org>

Acked-by: Tejun Heo <tj@...nel.org>

Thanks.

-- 
tejun
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