linux-kernel - Re: [PATCH] switch free memory back to MIGRATE

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: <20090713113326.624F.A69D9226@jp.fujitsu.com>
Date:	Mon, 13 Jul 2009 11:47:46 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Shaohua Li <shaohua.li@...el.com>
Cc:	kosaki.motohiro@...fujitsu.com, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, mel@....ul.ie, akpm@...ux-foundation.org
Subject: Re: [PATCH] switch free memory back to MIGRATE_MOVABLE

> When page is back to buddy and its order is bigger than pageblock_order, we can
> switch its type to MIGRATE_MOVABLE. This can reduce fragmentation. The patch
> has obvious effect when read a block device and then drop caches.
> 
> Signed-off-by: Shaohua Li <shaohua.li@...el.com>

This patch change hot path, but there is no performance mesurement description.
Also, I don't like modification buddy core for only drop caches.



> ---
>  mm/page_alloc.c |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> Index: linux/mm/page_alloc.c
> ===================================================================
> --- linux.orig/mm/page_alloc.c	2009-07-10 11:36:07.000000000 +0800
> +++ linux/mm/page_alloc.c	2009-07-13 09:25:21.000000000 +0800
> @@ -475,6 +475,15 @@ static inline void __free_one_page(struc
>  		order++;
>  	}
>  	set_page_order(page, order);
> +
> +	if (order >= pageblock_order && migratetype != MIGRATE_MOVABLE) {
> +		int i;
> +
> +		migratetype = MIGRATE_MOVABLE;
> +		for (i = 0; i < (1 << (order - pageblock_order)); i++)
> +			set_pageblock_migratetype(page +
> +				i * pageblock_nr_pages, MIGRATE_MOVABLE);
> +	}
>  	list_add(&page->lru,
>  		&zone->free_area[order].free_list[migratetype]);
>  	zone->free_area[order].nr_free++;
> --
> 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/



--
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/