Re: [PATCH v6 13/37] lib: add allocation tagging support for memory allocation profiling
From: Klara Modin
Date: Fri Apr 05 2024 - 09:55:51 EST
Hi,
On 2024-03-21 17:36, Suren Baghdasaryan wrote:
Introduce CONFIG_MEM_ALLOC_PROFILING which provides definitions to easily
instrument memory allocators. It registers an "alloc_tags" codetag type
with /proc/allocinfo interface to output allocation tag information when
the feature is enabled.
CONFIG_MEM_ALLOC_PROFILING_DEBUG is provided for debugging the memory
allocation profiling instrumentation.
Memory allocation profiling can be enabled or disabled at runtime using
/proc/sys/vm/mem_profiling sysctl when CONFIG_MEM_ALLOC_PROFILING_DEBUG=n.
CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT enables memory allocation
profiling by default.
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Co-developed-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
With this commit (9e2dcefa791e9d14006b360fba3455510fd3325d in
next-20240404), randconfig with KCONFIG_SEED=0xE6264236 fails to build
with the attached error. The following patch fixes the build error for
me, but I don't know if it's correct.
Kind regards,
Klara Modin
diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
index 100ddf66eb8e..1c765d80298b 100644
--- a/include/linux/alloc_tag.h
+++ b/include/linux/alloc_tag.h
@@ -12,6 +12,7 @@
#include <asm/percpu.h>
#include <linux/cpumask.h>
#include <linux/static_key.h>
+#include <linux/irqflags.h>
struct alloc_tag_counters {
u64 bytes;
diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
new file mode 100644
index 000000000000..b970ff1c80dc
--- /dev/null
+++ b/include/linux/alloc_tag.h
@@ -0,0 +1,145 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * allocation tagging
+ */
+#ifndef _LINUX_ALLOC_TAG_H
+#define _LINUX_ALLOC_TAG_H
+
+#include <linux/bug.h>
+#include <linux/codetag.h>
+#include <linux/container_of.h>
+#include <linux/preempt.h>
+#include <asm/percpu.h>
+#include <linux/cpumask.h>
+#include <linux/static_key.h>
+
+struct alloc_tag_counters {
+ u64 bytes;
+ u64 calls;
+};
+
+/*
+ * An instance of this structure is created in a special ELF section at every
+ * allocation callsite. At runtime, the special section is treated as
+ * an array of these. Embedded codetag utilizes codetag framework.
+ */
+struct alloc_tag {
+ struct codetag ct;
+ struct alloc_tag_counters __percpu *counters;
+} __aligned(8);
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+
+static inline struct alloc_tag *ct_to_alloc_tag(struct codetag *ct)
+{
+ return container_of(ct, struct alloc_tag, ct);
+}
+
+#ifdef ARCH_NEEDS_WEAK_PER_CPU
+/*
+ * 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).
+ */
+#error "Memory allocation profiling is incompatible with ARCH_NEEDS_WEAK_PER_CPU"
+#endif
+
+#define DEFINE_ALLOC_TAG(_alloc_tag) \
+ static DEFINE_PER_CPU(struct alloc_tag_counters, _alloc_tag_cntr); \
+ static struct alloc_tag _alloc_tag __used __aligned(8) \
+ __section("alloc_tags") = { \
+ .ct = CODE_TAG_INIT, \
+ .counters = &_alloc_tag_cntr };
+
+DECLARE_STATIC_KEY_MAYBE(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
+ mem_alloc_profiling_key);
+
+static inline bool mem_alloc_profiling_enabled(void)
+{
+ return static_branch_maybe(CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT,
+ &mem_alloc_profiling_key);
+}
+
+static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag)
+{
+ struct alloc_tag_counters v = { 0, 0 };
+ struct alloc_tag_counters *counter;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ counter = per_cpu_ptr(tag->counters, cpu);
+ v.bytes += counter->bytes;
+ v.calls += counter->calls;
+ }
+
+ return v;
+}
+
+#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
+static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag)
+{
+ WARN_ONCE(ref && ref->ct,
+ "alloc_tag was not cleared (got tag for %s:%u)\n",
+ ref->ct->filename, ref->ct->lineno);
+
+ WARN_ONCE(!tag, "current->alloc_tag not set");
+}
+
+static inline void alloc_tag_sub_check(union codetag_ref *ref)
+{
+ WARN_ONCE(ref && !ref->ct, "alloc_tag was not set\n");
+}
+#else
+static inline void alloc_tag_add_check(union codetag_ref *ref, struct alloc_tag *tag) {}
+static inline void alloc_tag_sub_check(union codetag_ref *ref) {}
+#endif
+
+/* Caller should verify both ref and tag to be valid */
+static inline void __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
+{
+ ref->ct = &tag->ct;
+ /*
+ * We need in increment the call counter every time we have a new
+ * allocation or when we split a large allocation into smaller ones.
+ * Each new reference for every sub-allocation needs to increment call
+ * counter because when we free each part the counter will be decremented.
+ */
+ this_cpu_inc(tag->counters->calls);
+}
+
+static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag, size_t bytes)
+{
+ alloc_tag_add_check(ref, tag);
+ if (!ref || !tag)
+ return;
+
+ __alloc_tag_ref_set(ref, tag);
+ this_cpu_add(tag->counters->bytes, bytes);
+}
+
+static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes)
+{
+ struct alloc_tag *tag;
+
+ alloc_tag_sub_check(ref);
+ if (!ref || !ref->ct)
+ return;
+
+ tag = ct_to_alloc_tag(ref->ct);
+
+ this_cpu_sub(tag->counters->bytes, bytes);
+ this_cpu_dec(tag->counters->calls);
+
+ ref->ct = NULL;
+}
+
+#else /* CONFIG_MEM_ALLOC_PROFILING */
+
+#define DEFINE_ALLOC_TAG(_alloc_tag)
+static inline bool mem_alloc_profiling_enabled(void) { return false; }
+static inline void alloc_tag_add(union codetag_ref *ref, struct alloc_tag *tag,
+ size_t bytes) {}
+static inline void alloc_tag_sub(union codetag_ref *ref, size_t bytes) {}
+
+#endif /* CONFIG_MEM_ALLOC_PROFILING */
+
+#endif /* _LINUX_ALLOC_TAG_H */
In file included from ./arch/x86/include/asm/percpu.h:615,
from ./arch/x86/include/asm/preempt.h:6,
from ./include/linux/preempt.h:79,
from ./include/linux/alloc_tag.h:11,
from lib/alloc_tag.c:2:
./include/linux/alloc_tag.h: In function ‘__alloc_tag_ref_set’:
./include/asm-generic/percpu.h:155:9: error: implicit declaration of function ‘raw_local_irq_save’ [-Werror=implicit-function-declaration]
155 | raw_local_irq_save(__flags); \
| ^~~~~~~~~~~~~~~~~~
./include/asm-generic/percpu.h:410:41: note: in expansion of macro ‘this_cpu_generic_to_op’
410 | #define this_cpu_add_8(pcp, val) this_cpu_generic_to_op(pcp, val, +=)
| ^~~~~~~~~~~~~~~~~~~~~~
./include/linux/percpu-defs.h:368:25: note: in expansion of macro ‘this_cpu_add_8’
368 | case 8: stem##8(variable, __VA_ARGS__);break; \
| ^~~~
./include/linux/percpu-defs.h:491:41: note: in expansion of macro ‘__pcpu_size_call’
491 | #define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, pcp, val)
| ^~~~~~~~~~~~~~~~
./include/linux/percpu-defs.h:501:41: note: in expansion of macro ‘this_cpu_add’
501 | #define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
| ^~~~~~~~~~~~
./include/linux/alloc_tag.h:106:9: note: in expansion of macro ‘this_cpu_inc’
106 | this_cpu_inc(tag->counters->calls);
| ^~~~~~~~~~~~
./include/asm-generic/percpu.h:157:9: error: implicit declaration of function ‘raw_local_irq_restore’ [-Werror=implicit-function-declaration]
157 | raw_local_irq_restore(__flags); \
| ^~~~~~~~~~~~~~~~~~~~~
./include/asm-generic/percpu.h:410:41: note: in expansion of macro ‘this_cpu_generic_to_op’
410 | #define this_cpu_add_8(pcp, val) this_cpu_generic_to_op(pcp, val, +=)
| ^~~~~~~~~~~~~~~~~~~~~~
./include/linux/percpu-defs.h:368:25: note: in expansion of macro ‘this_cpu_add_8’
368 | case 8: stem##8(variable, __VA_ARGS__);break; \
| ^~~~
./include/linux/percpu-defs.h:491:41: note: in expansion of macro ‘__pcpu_size_call’
491 | #define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, pcp, val)
| ^~~~~~~~~~~~~~~~
./include/linux/percpu-defs.h:501:41: note: in expansion of macro ‘this_cpu_add’
501 | #define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
| ^~~~~~~~~~~~
./include/linux/alloc_tag.h:106:9: note: in expansion of macro ‘this_cpu_inc’
106 | this_cpu_inc(tag->counters->calls);
| ^~~~~~~~~~~~
cc1: some warnings being treated as errors
make[3]: *** [scripts/Makefile.build:244: lib/alloc_tag.o] Error 1
make[2]: *** [scripts/Makefile.build:485: lib] Error 2
make[1]: *** [/home/klara/git/linux/Makefile:1919: .] Error 2
make: *** [Makefile:240: __sub-make] Error 2
Attachment:
randconfig.gz
Description: application/gzip
# bad: [2b3d5988ae2cb5cd945ddbc653f0a71706231fdd] Add linux-next specific files for 20240404
git bisect start 'next/master'
# status: waiting for good commit(s), bad commit known
# good: [39cd87c4eb2b893354f3b850f916353f2658ae6f] Linux 6.9-rc2
git bisect good 39cd87c4eb2b893354f3b850f916353f2658ae6f
# bad: [cc7b62666779616ff52d389a344ffe2c041e36e2] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git
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# bad: [d6b7dd0f8d84f9fdf2af65fceb608e3206276e81] Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux.git
git bisect bad d6b7dd0f8d84f9fdf2af65fceb608e3206276e81
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git bisect bad 085e5fe7388cf36ab5c02d91022229e5fade5b30
# bad: [f6a61baa9139d174170acdae8667b3246ce44db6] lib: add memory allocations report in show_mem()
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# good: [302519d9e80a7fbf2cf8d0b8961d491af648759f] asm-generic/io.h: kill vmalloc.h dependency
git bisect good 302519d9e80a7fbf2cf8d0b8961d491af648759f
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# good: [ed97151dec736c1541bfac2b801108d54ebee5bc] lib: code tagging module support
git bisect good ed97151dec736c1541bfac2b801108d54ebee5bc
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# bad: [9e2dcefa791e9d14006b360fba3455510fd3325d] lib: add allocation tagging support for memory allocation profiling
git bisect bad 9e2dcefa791e9d14006b360fba3455510fd3325d
# good: [0eccd42fbf9d7c4ae0cbec48cce637da89813c2c] lib: prevent module unloading if memory is not freed
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# first bad commit: [9e2dcefa791e9d14006b360fba3455510fd3325d] lib: add allocation tagging support for memory allocation profiling