+ lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: lib: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU
has been added to the -mm mm-unstable branch.  Its filename is
     lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: lib: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU
Date: Tue, 2 Apr 2024 11:09:33 -0700

ARCH_NEEDS_WEAK_PER_CPU does not allow percpu variable definitions inside
a function, therefore memory allocation profiling can't use it.  This
definition is used only for modules, so we still can account core kernel
allocations and for modules we can do limited allocation accounting by
charging all of them to a single counter.  This is not ideal but better
than no accounting at all.

Link: https://lkml.kernel.org/r/20240402180933.1663992-2-surenb@google.com
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403290334.USWrYrMw-lkp@intel.com/
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/alloc_tag.h |   14 ++++++++++++--
 lib/alloc_tag.c           |    3 +++
 2 files changed, 15 insertions(+), 2 deletions(-)

--- a/include/linux/alloc_tag.h~lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2
+++ a/include/linux/alloc_tag.h
@@ -39,9 +39,17 @@ static inline struct alloc_tag *ct_to_al
 /*
  * When percpu variables are required to be defined as weak, static percpu
  * variables can't be used inside a function (see comments for DECLARE_PER_CPU_SECTION).
+ * Instead we will accound all module allocations to a single counter.
  */
-#error "Memory allocation profiling is incompatible with ARCH_NEEDS_WEAK_PER_CPU"
-#endif
+DECLARE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
+
+#define DEFINE_ALLOC_TAG(_alloc_tag)						\
+	static struct alloc_tag _alloc_tag __used __aligned(8)			\
+	__section("alloc_tags") = {						\
+		.ct = CODE_TAG_INIT,						\
+		.counters = &_shared_alloc_tag };
+
+#else /* ARCH_NEEDS_WEAK_PER_CPU */
 
 #define DEFINE_ALLOC_TAG(_alloc_tag)						\
 	static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr);	\
@@ -50,6 +58,8 @@ static inline struct alloc_tag *ct_to_al
 		.ct = CODE_TAG_INIT,						\
 		.counters = &_alloc_tag_cntr };
 
+#endif /* ARCH_NEEDS_WEAK_PER_CPU */
+
 DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
 			mem_alloc_profiling_key);
 
--- a/lib/alloc_tag.c~lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2
+++ a/lib/alloc_tag.c
@@ -9,6 +9,9 @@
 
 static struct codetag_type *alloc_tag_cttype;
 
+DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
+EXPORT_SYMBOL(_shared_alloc_tag);
+
 DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
 			mem_alloc_profiling_key);
 
_

Patches currently in -mm which might be from surenb@google.com are

fix-missing-vmalloch-includes-fix-2.patch
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-add-allocation-tagging-support-for-memory-allocation-profiling-fix.patch
lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2.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-enable-page-allocation-tagging-fix.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-slab-enable-slab-allocation-tagging-for-kmalloc-and-friends-fix.patch
mempool-hook-up-to-memory-allocation-profiling-fix.patch
mm-percpu-enable-per-cpu-allocation-tagging.patch
mm-percpu-enable-per-cpu-allocation-tagging-fix.patch
mm-vmalloc-enable-memory-allocation-profiling-fix.patch
mm-vmalloc-enable-memory-allocation-profiling-fix-2.patch
rhashtable-plumb-through-alloc-tag-fix.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