linux-kernel - Re: [PATCH 3/12] ksm: pages_unshared and pages

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]

Date:	Tue, 4 Aug 2009 14:49:20 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Hugh Dickins <hugh.dickins@...cali.co.uk>
Cc:	ieidus@...hat.com, aarcange@...hat.com, riel@...hat.com,
	chrisw@...hat.com, nickpiggin@...oo.com.au,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 3/12] ksm: pages_unshared and pages_volatile

On Mon, 3 Aug 2009 13:11:53 +0100 (BST)
Hugh Dickins <hugh.dickins@...cali.co.uk> wrote:

> The pages_shared and pages_sharing counts give a good picture of how
> successful KSM is at sharing; but no clue to how much wasted work it's
> doing to get there.  Add pages_unshared (count of unique pages waiting
> in the unstable tree, hoping to find a mate) and pages_volatile.
> 
> pages_volatile is harder to define.  It includes those pages changing
> too fast to get into the unstable tree, but also whatever other edge
> conditions prevent a page getting into the trees: a high value may
> deserve investigation.  Don't try to calculate it from the various
> conditions: it's the total of rmap_items less those accounted for.
> 
> Also show full_scans: the number of completed scans of everything
> registered in the mm list.
> 
> The locking for all these counts is simply ksm_thread_mutex.
> 
> ...
>
>  static inline struct rmap_item *alloc_rmap_item(void)
>  {
> -	return kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL);
> +	struct rmap_item *rmap_item;
> +
> +	rmap_item = kmem_cache_zalloc(rmap_item_cache, GFP_KERNEL);
> +	if (rmap_item)
> +		ksm_rmap_items++;
> +	return rmap_item;
>  }

ksm_rmap_items was already available via /proc/slabinfo.  I guess that
wasn't a particularly nice user interface ;)

--
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/