Jim Bauer wrote:
On Friday 10 June 2005 19:16, Mauricio Lin wrote:
Hi lk,
Do you mean that pages (new copies of pages) generated through page fault handler are not cow, right?
Sounds right.
COW page is that one shared among processes for read access and invokes the page fault handler because a process tried to write to it, right?
yep. The MMU is told it is read-only, while the (I think) page tables have
it marked read-write. The fault handler seeing this understands it to
be a COW page, makes a read-write copy for the faulting process.
I thought that cow pages are those pages (new copies of pages) generated by page fault handler.
I think it would be better to say that COW pages are de-COWed by the
page fault handler. The copy that the page fault handler makes would not
be a COW page.
I dont think you mean that quite the way it sounds.
That page is also cow-able, so if that process were to fork/clone, the
page would be
shared between child and grand-child. It seems that parent or child
isnt even material to the
COW.
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