The patch titled Subject: mm/page_ext: enable early_page_ext when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y has been added to the -mm mm-unstable branch. Its filename is mm-page_ext-enable-early_page_ext-when-config_mem_alloc_profiling_debug=y.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_ext-enable-early_page_ext-when-config_mem_alloc_profiling_debug=y.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Suren Baghdasaryan <surenb@xxxxxxxxxx> Subject: mm/page_ext: enable early_page_ext when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y Date: Thu, 21 Mar 2024 09:36:43 -0700 For all page allocations to be tagged, page_ext has to be initialized before the first page allocation. Early tasks allocate their stacks using page allocator before alloc_node_page_ext() initializes page_ext area, unless early_page_ext is enabled. Therefore these allocations will generate a warning when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled. Enable early_page_ext whenever CONFIG_MEM_ALLOC_PROFILING_DEBUG=y to ensure page_ext initialization prior to any page allocation. This will have all the negative effects associated with early_page_ext, such as possible longer boot time, therefore we enable it only when debugging with CONFIG_MEM_ALLOC_PROFILING_DEBUG enabled and not universally for CONFIG_MEM_ALLOC_PROFILING. Link: https://lkml.kernel.org/r/20240321163705.3067592-22-surenb@xxxxxxxxxx Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alex Gaynor <alex.gaynor@xxxxxxxxx> Cc: Alice Ryhl <aliceryhl@xxxxxxxxxx> Cc: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> Cc: Benno Lossin <benno.lossin@xxxxxxxxx> Cc: "Björn Roy Baron" <bjorn3_gh@xxxxxxxxxxxxxx> Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Dennis Zhou <dennis@xxxxxxxxxx> Cc: Gary Guo <gary@xxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx> Cc: Miguel Ojeda <ojeda@xxxxxxxxxx> Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Wedson Almeida Filho <wedsonaf@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_ext.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/mm/page_ext.c~mm-page_ext-enable-early_page_ext-when-config_mem_alloc_profiling_debug=y +++ a/mm/page_ext.c @@ -95,7 +95,16 @@ unsigned long page_ext_size; static unsigned long total_usage; +#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG +/* + * To ensure correct allocation tagging for pages, page_ext should be available + * before the first page allocation. Otherwise early task stacks will be + * allocated before page_ext initialization and missing tags will be flagged. + */ +bool early_page_ext __meminitdata = true; +#else bool early_page_ext __meminitdata; +#endif static int __init setup_early_page_ext(char *str) { early_page_ext = true; _ Patches currently in -mm which might be from surenb@xxxxxxxxxx are mm-introduce-slabobj_ext-to-support-slab-object-extensions.patch mm-introduce-__gfp_no_obj_ext-flag-to-selectively-prevent-slabobj_ext-creation.patch mm-slab-introduce-slab_no_obj_ext-to-avoid-obj_ext-creation.patch slab-objext-introduce-objext_flags-as-extension-to-page_memcg_data_flags.patch lib-code-tagging-framework.patch lib-code-tagging-module-support.patch lib-prevent-module-unloading-if-memory-is-not-freed.patch lib-add-allocation-tagging-support-for-memory-allocation-profiling.patch lib-introduce-support-for-page-allocation-tagging.patch lib-introduce-early-boot-parameter-to-avoid-page_ext-memory-overhead.patch mm-percpu-increase-percpu_module_reserve-to-accommodate-allocation-tags.patch change-alloc_pages-name-in-dma_map_ops-to-avoid-name-conflicts.patch mm-enable-page-allocation-tagging.patch mm-create-new-codetag-references-during-page-splitting.patch mm-fix-non-compound-multi-order-memory-accounting-in-__free_pages.patch mm-page_ext-enable-early_page_ext-when-config_mem_alloc_profiling_debug=y.patch lib-add-codetag-reference-into-slabobj_ext.patch mm-slab-add-allocation-accounting-into-slab-allocation-and-free-paths.patch mm-slab-enable-slab-allocation-tagging-for-kmalloc-and-friends.patch mm-percpu-enable-per-cpu-allocation-tagging.patch lib-add-memory-allocations-report-in-show_mem.patch codetag-debug-skip-objext-checking-when-its-for-objext-itself.patch codetag-debug-mark-codetags-for-reserved-pages-as-empty.patch codetag-debug-introduce-objexts_alloc_fail-to-mark-failed-slab_ext-allocations.patch