Re: Should a swapped out page be deleted from swap cache?

From: Will Huck
Date: Tue Feb 19 2013 - 19:43:41 EST

On 02/20/2013 03:06 AM, Hugh Dickins wrote:
On Tue, 19 Feb 2013, Will Huck wrote:
Another question:
I don't see the connection to deleting a swapped out page from swap cache.

Why kernel memory mapping use direct mapping instead of kmalloc/vmalloc which
will setup mapping on demand?
I may misunderstand you, and "kernel memory mapping".

kmalloc does not set up a mapping, it uses the direct mapping already set up.

It would be circular if the basic page allocation primitives used kmalloc,
since kmalloc relies on the basic page allocation primitives.

vmalloc is less efficient than using the direct mapping (repeated setup
and teardown, no use of hugepages), but necessary when you want a larger

Is there tlb flush in setup and teardown process? and they also expensive?

virtual array than you're likely to find from the buddy allocator.


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