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Date: Tue, 17 Dec 2024 12:11:42 +0530
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Subject: Re: [RFC PATCH 05/12] khugepaged: Generalize
 __collapse_huge_page_isolate()
To: Matthew Wilcox <willy@infradead.org>, g@casper.infradead.org
Cc: akpm@linux-foundation.org, david@redhat.com,
 kirill.shutemov@linux.intel.com, ryan.roberts@arm.com,
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References: <20241216165105.56185-1-dev.jain@arm.com>
 <20241216165105.56185-6-dev.jain@arm.com>
 <Z2D-5y65onX_qOLi@casper.infradead.org>
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From: Dev Jain <dev.jain@arm.com>
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On 17/12/24 10:02 am, Matthew Wilcox wrote:
> On Mon, Dec 16, 2024 at 10:20:58PM +0530, Dev Jain wrote:
>>   {
>> -	struct page *page = NULL;
>> -	struct folio *folio = NULL;
>> -	pte_t *_pte;
>> +	unsigned int max_ptes_shared = khugepaged_max_ptes_shared >> (HPAGE_PMD_ORDER - order);
>> +	unsigned int max_ptes_none = khugepaged_max_ptes_none >> (HPAGE_PMD_ORDER - order);
>>   	int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0;
>> +	struct folio *folio = NULL;
>> +	struct page *page = NULL;
> why are you moving variables around unnecessarily?

In a previous work, I moved code around and David noted to arrange the declarations
in reverse Xmas tree order. I guess (?) that was not spoiling git history, so if
this feels like that, I will revert.

>
>>   	bool writable = false;
>> +	pte_t *_pte;
>>   
>> -	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
>> +
>> +	for (_pte = pte; _pte < pte + (1UL << order);
> spurious blank line

My bad

>
>
> also you might first want to finish off the page->folio conversion in
> this function first; we have a vm_normal_folio() now.

I did not add any code before we derive the folio...I'm sorry, I don't get what you mean...