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.
