lib: add memory allocations report in show_mem()

Include allocations in show_mem reports.

Link: https://lkml.kernel.org/r/20240321163705.3067592-33-surenb@google.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/alloc_tag.h

@@ -31,6 +31,13 @@ struct alloc_tag {
 
 #ifdef CONFIG_MEM_ALLOC_PROFILING
 
+struct codetag_bytes {
+	struct codetag *ct;
+	s64 bytes;
+};
+
+size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep);
+
 static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct)
 {
 	return container_of(ct, struct alloc_tag, ct);

include/linux/codetag.h

@@ -61,6 +61,7 @@ struct codetag_iterator {
 }
 
 void codetag_lock_module_list(struct codetag_type *cttype, bool lock);
+bool codetag_trylock_module_list(struct codetag_type *cttype);
 struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype);
 struct codetag *codetag_next_ct(struct codetag_iterator *iter);
 

lib/alloc_tag.c

@@ -89,6 +89,44 @@ static const struct seq_operations allocinfo_seq_op = {
 	.show	= allocinfo_show,
 };
 
+size_t alloc_tag_top_users(struct codetag_bytes *tags, size_t count, bool can_sleep)
+{
+	struct codetag_iterator iter;
+	struct codetag *ct;
+	struct codetag_bytes n;
+	unsigned int i, nr = 0;
+
+	if (can_sleep)
+		codetag_lock_module_list(alloc_tag_cttype, true);
+	else if (!codetag_trylock_module_list(alloc_tag_cttype))
+		return 0;
+
+	iter = codetag_get_ct_iter(alloc_tag_cttype);
+	while ((ct = codetag_next_ct(&iter))) {
+		struct alloc_tag_counters counter = alloc_tag_read(ct_to_alloc_tag(ct));
+
+		n.ct	= ct;
+		n.bytes = counter.bytes;
+
+		for (i = 0; i < nr; i++)
+			if (n.bytes > tags[i].bytes)
+				break;
+
+		if (i < count) {
+			nr -= nr == count;
+			memmove(&tags[i + 1],
+				&tags[i],
+				sizeof(tags[0]) * (nr - i));
+			nr++;
+			tags[i] = n;
+		}
+	}
+
+	codetag_lock_module_list(alloc_tag_cttype, false);
+
+	return nr;
+}
+
 static void __init procfs_init(void)
 {
 	proc_create_seq("allocinfo", 0444, NULL, &allocinfo_seq_op);

lib/codetag.c

@@ -36,6 +36,11 @@ void codetag_lock_module_list(struct codetag_type *cttype, bool lock)
 		up_read(&cttype->mod_lock);
 }
 
+bool codetag_trylock_module_list(struct codetag_type *cttype)
+{
+	return down_read_trylock(&cttype->mod_lock) != 0;
+}
+
 struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype)
 {
 	struct codetag_iterator iter = {

mm/show_mem.c

@@ -423,4 +423,30 @@ void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
 #ifdef CONFIG_MEMORY_FAILURE
 	printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages));
 #endif
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+	{
+		struct codetag_bytes tags[10];
+		size_t i, nr;
+
+		nr = alloc_tag_top_users(tags, ARRAY_SIZE(tags), false);
+		if (nr) {
+			pr_notice("Memory allocations:\n");
+			for (i = 0; i < nr; i++) {
+				struct codetag *ct = tags[i].ct;
+				struct alloc_tag *tag = ct_to_alloc_tag(ct);
+				struct alloc_tag_counters counter = alloc_tag_read(tag);
+
+				/* Same as alloc_tag_to_text() but w/o intermediate buffer */
+				if (ct->modname)
+					pr_notice("%12lli %8llu %s:%u [%s] func:%s\n",
+						  counter.bytes, counter.calls, ct->filename,
+						  ct->lineno, ct->modname, ct->function);
+				else
+					pr_notice("%12lli %8llu %s:%u func:%s\n",
+						  counter.bytes, counter.calls, ct->filename,
+						  ct->lineno, ct->function);
+			}
+		}
+	}
+#endif
 }