+ mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters.patch added to mm-new branch

+ mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/alloc_tag: add the ARCH_NEEDS_WEAK_PER_CPU macro when statically defining the percpu variable alloc_tag_counters.
has been added to the -mm mm-new branch.  Its filename is
     mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
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fixup patches in mm-new.

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------------------------------------------------------
From: Hao Ge <gehao@kylinos.cn>
Subject: mm/alloc_tag: add the ARCH_NEEDS_WEAK_PER_CPU macro when statically defining the percpu variable alloc_tag_counters.
Date: Thu, 29 May 2025 15:35:37 +0800

Recently discovered this entry while checking kallsyms on ARM64:
ffff800083e509c0 D _shared_alloc_tag

If ARCH_NEEDS_WEAK_PER_CPU is not defined,there's no need to statically
define the percpu variable alloc_tag_counters.

Therefore, add the relevant macro guards at the appropriate location.

Link: https://lkml.kernel.org/r/20250529073537.563107-1-hao.ge@linux.dev
Fixes: 22d407b164ff ("lib: add allocation tagging support for memory allocation profiling")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/alloc_tag.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/lib/alloc_tag.c~mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters
+++ a/lib/alloc_tag.c
@@ -24,8 +24,10 @@ static bool mem_profiling_support;
 
 static struct codetag_type *alloc_tag_cttype;
 
+#ifdef ARCH_NEEDS_WEAK_PER_CPU
 DEFINE_PER_CPU(struct alloc_tag_counters, _shared_alloc_tag);
 EXPORT_SYMBOL(_shared_alloc_tag);
+#endif /* ARCH_NEEDS_WEAK_PER_CPU */
 
 DEFINE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
 			mem_alloc_profiling_key);
_

Patches currently in -mm which might be from gehao@kylinos.cn are

mm-alloc_tag-add-the-arch_needs_weak_per_cpu-macro-when-statically-defining-the-percpu-variable-alloc_tag_counters.patch