On 4/10/2024 4:15 PM, Jane Chu wrote:
On 4/10/2024 3:21 AM, Oscar Salvador wrote:
On Mon, Apr 08, 2024 at 05:34:29PM -0700, Jane Chu wrote:
At this stage, 'p' is not expected to be a large page since a
_refcount has
been taken, right? So is it reasonable to replace the "if (retry)"
block
with a VM_BUG_ON warning? otherwise, if 'p' became part of a different
large folio, how to recover from here ?
We might have split the THP (if it was part of), but AFAICS
nothing stops the kernel to coallesce this page again into a new THP
via e.g:
madvise(MADV_HUGEPAGE) ?
Good point, thanks!
Come to think of it a bit more, maybe the check could be
if (folio_test_large(folio) || (folio != page_folio(p))) {
? Because, 'p' could have become part of a THP after shake_folio() and
before folio_lock(), right?
thanks,
-jane
-jane
