| Message ID | 20230117204617.1553748-1-pasha.tatashin@soleen.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/page_ext: init page_ext early if there are no deferred struct pages | expand |
On Tue, 17 Jan 2023 20:46:17 +0000 Pasha Tatashin <pasha.tatashin@soleen.com> wrote: > page_ext must be initialized after all struct pages are initialized. > Therefore, page_ext is initialized after page_alloc_init_late(), and > can optionally be initialized earlier via early_page_ext kernel > parameter which as a side effect also disables deferred struct pages. > > Allow to automatically init page_ext early when there are no deferred > struct pages in order to be able to use page_ext during kernel boot > and track for example page allocations early. Compilation blows up with CONFIG_PAGE_EXTENSION=n. I did --- a/include/linux/page_ext.h~mm-page_ext-init-page_ext-early-if-there-are-no-deferred-struct-pages-fix +++ a/include/linux/page_ext.h @@ -92,6 +92,7 @@ static inline struct page_ext *page_ext_ #else /* !CONFIG_PAGE_EXTENSION */ struct page_ext; +#define deferred_struct_pages (0) static inline bool early_page_ext_enabled(void) { but it then blew up differently.
On Tue, Jan 17, 2023 at 8:13 PM Andrew Morton <akpm@linux-foundation.org> wrote: > > On Tue, 17 Jan 2023 20:46:17 +0000 Pasha Tatashin <pasha.tatashin@soleen.com> wrote: > > > page_ext must be initialized after all struct pages are initialized. > > Therefore, page_ext is initialized after page_alloc_init_late(), and > > can optionally be initialized earlier via early_page_ext kernel > > parameter which as a side effect also disables deferred struct pages. > > > > Allow to automatically init page_ext early when there are no deferred > > struct pages in order to be able to use page_ext during kernel boot > > and track for example page allocations early. > > Compilation blows up with CONFIG_PAGE_EXTENSION=n. I did Thanks, I will update the patch and send it soon. Pasha
diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h index 22be4582faae..1e9bcc37a342 100644 --- a/include/linux/page_ext.h +++ b/include/linux/page_ext.h @@ -36,6 +36,7 @@ struct page_ext { unsigned long flags; }; +extern bool deferred_struct_pages; extern bool early_page_ext; extern unsigned long page_ext_size; extern void pgdat_page_ext_init(struct pglist_data *pgdat); diff --git a/init/main.c b/init/main.c index e1c3911d7c70..64cd2ff051c4 100644 --- a/init/main.c +++ b/init/main.c @@ -855,8 +855,8 @@ static void __init mm_init(void) pgtable_init(); debug_objects_mem_init(); vmalloc_init(); - /* Should be run after vmap initialization */ - if (early_page_ext_enabled()) + /* If no deferred init page_ext now, as vmap is fully initialized */ + if (!deferred_struct_pages) page_ext_init(); /* Should be run before the first non-init thread is created */ init_espfix_bsp(); @@ -1628,7 +1628,7 @@ static noinline void __init kernel_init_freeable(void) padata_init(); page_alloc_init_late(); /* Initialize page ext after all struct pages are initialized. */ - if (!early_page_ext_enabled()) + if (deferred_struct_pages) page_ext_init(); do_basic_setup(); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0745aedebb37..5a3e0f00f31d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -430,6 +430,8 @@ EXPORT_SYMBOL(nr_online_nodes); int page_group_by_mobility_disabled __read_mostly; +bool deferred_struct_pages __meminitdata; + #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* * During boot we initialize deferred pages on-demand, as needed, but once @@ -6761,8 +6763,10 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone if (context == MEMINIT_EARLY) { if (overlap_memmap_init(zone, &pfn)) continue; - if (defer_init(nid, pfn, zone_end_pfn)) + if (defer_init(nid, pfn, zone_end_pfn)) { + deferred_struct_pages = true; break; + } } page = pfn_to_page(pfn); diff --git a/mm/page_ext.c b/mm/page_ext.c index 4ee522fd381c..918e2e131ab0 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -91,7 +91,7 @@ unsigned long page_ext_size = sizeof(struct page_ext); static unsigned long total_usage; static struct page_ext *lookup_page_ext(const struct page *page); -bool early_page_ext; +bool early_page_ext __meminitdata; static int __init setup_early_page_ext(char *str) { early_page_ext = true;
page_ext must be initialized after all struct pages are initialized. Therefore, page_ext is initialized after page_alloc_init_late(), and can optionally be initialized earlier via early_page_ext kernel parameter which as a side effect also disables deferred struct pages. Allow to automatically init page_ext early when there are no deferred struct pages in order to be able to use page_ext during kernel boot and track for example page allocations early. Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> --- include/linux/page_ext.h | 1 + init/main.c | 6 +++--- mm/page_alloc.c | 6 +++++- mm/page_ext.c | 2 +- 4 files changed, 10 insertions(+), 5 deletions(-)