Date: Thu, 12 Jun 2014 12:25:46 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
        Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Scott J Norton <scott.norton@hp.com>
Subject: Re: [PATCH] mm: Move __vma_address() to internal.h to be inlined in
 huge_memory.c
Message-Id: <20140612122546.cfdebdb22bb22c0f767e30b5@linux-foundation.org>
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References: <1402600540-52031-1-git-send-email-Waiman.Long@hp.com>
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On Thu, 12 Jun 2014 15:15:40 -0400 Waiman Long <Waiman.Long@hp.com> wrote:

> The vma_address() function which is used to compute the virtual address
> within a VMA is used only by 2 files in the mm subsystem - rmap.c and
> huge_memory.c. This function is defined in rmap.c and is inlined by
> its callers there, but it is also declared as an external function.
> 
> However, the __split_huge_page() function which calls vma_address()
> in huge_memory.c is calling it as a real function call. This is not
> as efficient as an inlined function. This patch moves the underlying
> inlined __vma_address() function to internal.h to be shared by both
> the rmap.c and huge_memory.c file.

This increases huge_memory.o's text+data_bss by 311 bytes, which makes
me suspect that it is a bad change due to its increase of kernel cache
footprint.

Perhaps we should be noinlining __vma_address()?
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