Re: [RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use

2012-12-01 Thread Rik van Riel
On 12/01/2012 01:38 PM, Linus Torvalds wrote: On Sat, Dec 1, 2012 at 4:26 AM, Ingo Molnar wrote: So as a quick concept hack I wrote the patch attached below. (It's not signed off, see the patch description text for the reason.) Well, it confirms that anon_vma locking is a big problem, but a

Re: [RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use

2012-12-01 Thread Linus Torvalds
On Sat, Dec 1, 2012 at 10:41 AM, Ingo Molnar wrote: > > I'll try the rwsem and see how it goes? Yeah. That should be an easy conversion (just convert everything to use the write-lock first, and then you can make one or two migration places use the read version). Side note: The mutex code tends t

Re: [RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use

2012-12-01 Thread Ingo Molnar
* Linus Torvalds wrote: > On Sat, Dec 1, 2012 at 4:26 AM, Ingo Molnar wrote: > > > > > > So as a quick concept hack I wrote the patch attached below. > > (It's not signed off, see the patch description text for the > > reason.) > > Well, it confirms that anon_vma locking is a big problem, but

Re: [RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use

2012-12-01 Thread Linus Torvalds
On Sat, Dec 1, 2012 at 4:26 AM, Ingo Molnar wrote: > > > So as a quick concept hack I wrote the patch attached below. > (It's not signed off, see the patch description text for the > reason.) Well, it confirms that anon_vma locking is a big problem, but as outlined in my other email it's complete

[RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use

2012-12-01 Thread Ingo Molnar
* Ingo Molnar wrote: > 1) > > This patch might solve the remapping > (remove_migration_ptes()), but does not solve the anon-vma > locking done in the first, unmapping step of pte-migration - > which is done via try_to_unmap(): which is a generic VM > function used by swapout too, so callers