On 05.06.24 04:20, ran xiaokai wrote:
On 04.06.24 07:47, xu.xin16@xxxxxxxxxx wrote:
From: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
When I did a large folios split test, a WARNING
"[ 5059.122759][ T166] Cannot split file folio to non-0 order"
was triggered. But my test cases are only for anonmous folios.
while mapping_large_folio_support() is only reasonable for page
cache folios.
Agreed.
I wonder if mapping_large_folio_support() should either
a) Complain if used for anon folios, so we can detect the wrong use more
easily. (VM_WARN_ON_ONCE())
b) Return "true" for anonymous mappings, although that's more debatable.
Hi, David,
Thanks for the review.
I think a) is better.
But we have to add a new parameter "folio" to mapping_large_folio_support(), right ?
something like mapping_large_folio_support(struct address_space *mapping, struct folio *folio) ?
But in the __filemap_get_folio() path,
__filemap_get_folio()
no_page:
....
if (!mapping_large_folio_support(mapping))
the folio is not allocated yet, yes ?
Or do you mean there is some other way to do this ?
If we really pass unmodified folio->mapping, you can do what
folio_test_anon() would and make sure PAGE_MAPPING_ANON is not set.
--
Cheers,
David / dhildenb
