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From: David Hildenbrand <david@redhat.com>
To: Mounesh Badiger <mounesh.b@gmail.com>, linux-mm@kvack.org
Subject: Re: kmalloc() question - migration/remap of kmalloc()'ed pages
Date: Thu, 25 Apr 2024 11:36:37 +0200	[thread overview]
Message-ID: <20493de7-9367-4453-84c4-23d2db1b5986@redhat.com> (raw)
In-Reply-To: <CAOGU1pyhL=g7Ammo089K_S8dLh7Xdyhh=KDwtB=JE0KnAW5Q8w@mail.gmail.com>

On 25.04.24 11:21, Mounesh Badiger wrote:
> Hi,

Hi,

> 
> We have a device driver that allocates physical pages using kmalloc() 
> and these pages are mapped to the userspace process via mmap.

Which interface are you using for inserting these pages into the page 
tables?

remap_pfn_range? vm_insert_page() ? ...

Using kmalloc sound weird ... why not simply alloc_pages()?

> 
> Does the kmalloc()'ed memory mapped to userspace can migrate or get 
> remapped due to any of kernel mm operations?

No.

> 
> we are looking to keep VA->PA mapping intact from a 
> userspace process point of view.

That will work.

-- 
Cheers,

David / dhildenb



  reply	other threads:[~2024-04-25  9:36 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-25  9:21 Mounesh Badiger
2024-04-25  9:36 ` David Hildenbrand [this message]
2024-04-25  9:48   ` Mounesh Badiger
2024-04-25  9:51     ` David Hildenbrand

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