Re: [PATCH] page-allocator: Remove dead function free_cold_page()

From: Andrew Morton
Date: Wed Aug 05 2009 - 21:53:31 EST


On Wed, 5 Aug 2009 11:28:17 +0100 Mel Gorman <mel@xxxxxxxxx> wrote:

> The function free_cold_page() has no callers so delete it.
>
> Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
> ---
> include/linux/gfp.h | 1 -
> mm/page_alloc.c | 5 -----
> 2 files changed, 6 deletions(-)
>
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index 7c777a0..c32bfa8 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -326,7 +326,6 @@ void free_pages_exact(void *virt, size_t size);
> extern void __free_pages(struct page *page, unsigned int order);
> extern void free_pages(unsigned long addr, unsigned int order);
> extern void free_hot_page(struct page *page);
> -extern void free_cold_page(struct page *page);
>
> #define __free_page(page) __free_pages((page), 0)
> #define free_page(addr) free_pages((addr),0)
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index d052abb..36758db 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1065,11 +1065,6 @@ void free_hot_page(struct page *page)
> free_hot_cold_page(page, 0);
> }
>
> -void free_cold_page(struct page *page)
> -{
> - free_hot_cold_page(page, 1);
> -}
> -
> /*
> * split_page takes a non-compound higher-order page, and splits it into
> * n (1<<order) sub-pages: page[0..n]

Well I spose so. But the function is valid and might need to be
resurrected at any stage. We could `#if 0' it to save a few bytes of
text, perhaps.

I wonder how many free_page() callers should really be calling
free_cold_page(). c'mon, write a thingy to work it out ;) You can
query a page's hotness by timing how long it takes to read all its
cachelines.


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