Messages in this thread | | | Date | Wed, 19 Apr 2006 12:39:11 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: Read/Write migration entries: Implement correct behavior in copy_one_pte |
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On Tue, 18 Apr 2006 18:27:28 -0700 (PDT) Christoph Lameter <clameter@sgi.com> wrote:
> On Wed, 19 Apr 2006, KAMEZAWA Hiroyuki wrote: > > > > Note that this is again only a partial solution. mprotect() also has the > > > potential of changing the write status to read. > > yes. in change_pte_range(). > > > > Note: > > fork() and mprotect() both requires mm->mmap_sem. > > So both of them is not problem when migration holds mm->mmap_sem. > > If we does lazy migration or memory hot removing or allows migration from > > another process, this will be problem. > > Oh. We already allow migration from another process since the page may > be mapped by multiple mm's. Page migration will then replace the ptes in > *all* mm_structs that map this page with migration entries. > > So we need a fix here. > Ah.....yes. sorry.
In my understanding (and grep), read/write protection for anon pages can be changed under
- fork() - mprotect()
all are known.
BTW, do we manage page table under move_vma() in right way ?
-Kame
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