From: Zhenhua Huang <zhenhuah@xxxxxxxxxxxxxx> Subject: mm: fix page_owner initializing issue for arm32 Page owner of pages used by page owner itself used is missing on arm32 targets. The reason is dummy_handle and failure_handle is not initialized correctly. Buddy allocator is used to initialize these two handles. However, buddy allocator is not ready when page owner calls it. This change fixed that by initializing page owner after buddy initialization. The working flow before and after this change are: original logic: 1. allocated memory for page_ext(using memblock). 2. invoke the init callback of page_ext_ops like page_owner(using buddy allocator). 3. initialize buddy. after this change: 1. allocated memory for page_ext(using memblock). 2. initialize buddy. 3. invoke the init callback of page_ext_ops like page_owner(using buddy allocator). with the change, failure/dummy_handle can get its correct value and page owner output for example has the one for page owner itself: Page allocated via order 2, mask 0x6202c0(GFP_USER|__GFP_NOWARN), pid 1006, ts 67278156558 ns PFN 543776 type Unmovable Block 531 type Unmovable Flags 0x0() init_page_owner+0x28/0x2f8 invoke_init_callbacks_flatmem+0x24/0x34 start_kernel+0x33c/0x5d8 (null) Link: https://lkml.kernel.org/r/1603104925-5888-1-git-send-email-zhenhuah@xxxxxxxxxxxxxx Signed-off-by: Zhenhua Huang <zhenhuah@xxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/page_ext.h | 8 ++++++++ init/main.c | 2 ++ mm/page_ext.c | 10 ++++++++-- 3 files changed, 18 insertions(+), 2 deletions(-) --- a/include/linux/page_ext.h~mm-fix-page_owner-initializing-issue-for-arm32 +++ a/include/linux/page_ext.h @@ -44,8 +44,12 @@ static inline void page_ext_init_flatmem { } extern void page_ext_init(void); +static inline void page_ext_init_flatmem_late(void) +{ +} #else extern void page_ext_init_flatmem(void); +extern void page_ext_init_flatmem_late(void); static inline void page_ext_init(void) { } @@ -76,6 +80,10 @@ static inline void page_ext_init(void) { } +static inline void page_ext_init_flatmem_late(void) +{ +} + static inline void page_ext_init_flatmem(void) { } --- a/init/main.c~mm-fix-page_owner-initializing-issue-for-arm32 +++ a/init/main.c @@ -828,6 +828,8 @@ static void __init mm_init(void) init_debug_pagealloc(); report_meminit(); mem_init(); + /* page_owner must be initialized after buddy is ready */ + page_ext_init_flatmem_late(); kmem_cache_init(); kmemleak_init(); pgtable_init(); --- a/mm/page_ext.c~mm-fix-page_owner-initializing-issue-for-arm32 +++ a/mm/page_ext.c @@ -99,12 +99,19 @@ static void __init invoke_init_callbacks } } +#ifndef CONFIG_SPARSEMEM +void __init page_ext_init_flatmem_late(void) +{ + invoke_init_callbacks(); +} +#endif + static inline struct page_ext *get_entry(void *base, unsigned long index) { return base + page_ext_size * index; } -#if !defined(CONFIG_SPARSEMEM) +#ifndef CONFIG_SPARSEMEM void __meminit pgdat_page_ext_init(struct pglist_data *pgdat) @@ -177,7 +184,6 @@ void __init page_ext_init_flatmem(void) goto fail; } pr_info("allocated %ld bytes of page_ext\n", total_usage); - invoke_init_callbacks(); return; fail: _
