On Fri, Nov 10, 2023 at 11:33:20AM +0800, Kefeng Wang wrote:
kpageflags reads page-flags directly from the page, even when the
respective flag is only updated on the headpage of a folio.
Since most flags are stored in head flags, make k = folio->flags,
and add new p = page->flags used for per-page flags.
You'd do better to steal Greg's commit message.
Originally-from: Gregory Price <gregory.price@xxxxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
@@ -202,7 +202,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
#ifdef CONFIG_MEMORY_FAILURE
- u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
+ u |= kpf_copy_bit(p, KPF_HWPOISON, PG_hwpoison);
This is correct.
@@ -211,13 +211,13 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
- u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
- u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
- u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
+ u |= kpf_copy_bit(p, KPF_PRIVATE, PG_private);
+ u |= kpf_copy_bit(p, KPF_PRIVATE_2, PG_private_2);
+ u |= kpf_copy_bit(p, KPF_OWNER_PRIVATE, PG_owner_priv_1);
This is not. PG_private is not, I believe, set on tail pages.
Ditto the other two. If you know differently ... ?
#ifdef CONFIG_ARCH_USES_PG_ARCH_X
- u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
- u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
+ u |= kpf_copy_bit(p, KPF_ARCH_2, PG_arch_2);
+ u |= kpf_copy_bit(p, KPF_ARCH_3, PG_arch_3);
#endif
I also don't think this is correct, but there are many uses of
PG_arch* and I may have missed something.