linux-kernel - Re: [PATCH] mm, kmemleak: Little optimization while scanning

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Date:   Fri, 7 Dec 2018 09:26:46 +0000
From:   Wei Yang <richard.weiyang@...il.com>
To:     Oscar Salvador <osalvador@...e.de>
Cc:     Wei Yang <richard.weiyang@...il.com>, akpm@...ux-foundation.org,
        catalin.marinas@....com, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, mhocko@...e.com
Subject: Re: [PATCH] mm, kmemleak: Little optimization while scanning

On Fri, Dec 07, 2018 at 07:14:10AM +0100, Oscar Salvador wrote:
>
>> > +
>> 
>> This one maybe not necessary.
>
>Yeah, that is a remind of an include file I used for time measurement.
>I hope Andrew can drop that if this is taken.
>
>> > /*
>> >  * Kmemleak configuration and common defines.
>> >  */
>> > @@ -1547,11 +1548,14 @@ static void kmemleak_scan(void)
>> > 		unsigned long pfn;
>> > 
>> > 		for (pfn = start_pfn; pfn < end_pfn; pfn++) {
>> > -			struct page *page;
>> > +			struct page *page =
>> > pfn_to_online_page(pfn);
>> > +
>> > +			if (!page)
>> > +				continue;
>> > 
>> > -			if (!pfn_valid(pfn))
>> > +			/* only scan pages belonging to this node
>> > */
>> > +			if (page_to_nid(page) != i)
>> > 				continue;
>> 
>> Not farmiliar with this situation. Is this often?
>Well, hard to tell how often that happens because that mostly depends
>on the Hardware in case of baremetal.
>Virtual systems can also have it though.
>

Ok, generally looks good to me.

Reviewed-by: Wei Yang <richard.weiyang@...il.com>

>> 
>> > -			page = pfn_to_page(pfn);
>> > 			/* only scan if page is in use */
>> > 			if (page_count(page) == 0)
>> > 				continue;
>> > -- 
>> > 2.13.7
>> 
>> 
>-- 
>Oscar Salvador
>SUSE L3

-- 
Wei Yang
Help you, Help me