linux-kernel - Re: [PATCH v3 06/22] mm/mshare: Add a vma flag to indicate an mshare region

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Message-ID: <b99517e5-7b4b-494e-8ec6-918f933ddf50@oracle.com>
Date: Mon, 8 Sep 2025 11:56:54 -0700
From: Anthony Yznaga <anthony.yznaga@...cle.com>
To: David Hildenbrand <david@...hat.com>, linux-mm@...ck.org
Cc: akpm@...ux-foundation.org, andreyknvl@...il.com, arnd@...db.de,
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Subject: Re: [PATCH v3 06/22] mm/mshare: Add a vma flag to indicate an mshare
 region



On 9/8/25 11:45 AM, David Hildenbrand wrote:
> On 20.08.25 03:03, Anthony Yznaga wrote:
>> From: Khalid Aziz <khalid@...nel.org>
>>
>> An mshare region contains zero or more actual vmas that map objects
>> in the mshare range with shared page tables.
>>
>> Signed-off-by: Khalid Aziz <khalid@...nel.org>
>> Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
>> Signed-off-by: Anthony Yznaga <anthony.yznaga@...cle.com>
>> ---
> 
> Why can't we query the mapping instead?
> 


The bit check is nice and zippy since vma_is_mshare() is called for 
every fault, but it's not required. The check could be made to be:

	return vma->vm_ops == &msharefs_vm_ops;