linux-kernel - Re: [PATCH] CPA: Add statistics about state of direct mapping v3

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Date:	Tue, 25 Mar 2008 16:40:43 +0100 (CET)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Andi Kleen <andi@...stfloor.org>
cc:	andreas.herrmann3@....com, mingo@...e.hu,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] CPA: Add statistics about state of direct mapping v3

On Sat, 22 Mar 2008, Andi Kleen wrote:

> [I didn't switch to debugfs because I strongly disagreed with that
> suggestion. But all the other points you made are addressed.]

Halfways :)
  
> +static void update_page_count(int level, unsigned long pages)
> +{
> +#ifdef CONFIG_PROC_FS
> +	unsigned long flags;
> +	/* Protect against CPA */
> +	spin_lock_irqsave(&pgd_lock, flags);
> +	direct_pages_count[PG_LEVEL_2M] += pages;

Shouldn't this update direct_pages_count[level] perhaps ?

> +	spin_unlock_irqrestore(&pgd_lock, flags);
> +#endif
> +}

Also I asked to move the update function to pageattr.c where we have
the variable, so we dont need to make it global and can change the
statistics implementation w/o changing the callers

> @@ -356,6 +371,7 @@ phys_pmd_update(pud_t *pud, unsigned lon
>  static unsigned long __meminit
>  phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
>  {
> +	unsigned long pages = 0;
>  	unsigned long true_end = end;
>  	int i = pud_index(addr);
>  
> @@ -380,6 +396,7 @@ phys_pud_init(pud_t *pud_page, unsigned 
>  		}
>  
>  		if (direct_gbpages) {
> +			direct_pages_count[PG_LEVEL_1G]++;

  direct update

>  			set_pte((pte_t *)pud,
>  				pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
>  			true_end = (addr & PUD_MASK) + PUD_SIZE;
> @@ -397,6 +414,8 @@ phys_pud_init(pud_t *pud_page, unsigned 
>  	}
>  	__flush_tlb_all();
>  
> +	update_page_count(PG_LEVEL_1G, pages);
> +

  update via function call with pages = 0 ?

Thanks,

	tglx
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