Messages in this thread | | | Date | Wed, 20 Feb 2013 08:43:30 +0800 | From | Will Huck <> | Subject | Re: Should a swapped out page be deleted from swap cache? |
| |
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. > > Hugh
| |