[PATCH] Add accumulated call counter for memory allocation profiling

From: David Wang
Date: Mon Jun 17 2024 - 11:53:01 EST


Accumulated call counter can be used to evaluate rate
of memory allocation via delta(counters)/delta(time).
This metrics can help analysis performance behaviours,
e.g. tuning cache size, etc.

Signed-off-by: David Wang <00107082@xxxxxxx>
---
include/linux/alloc_tag.h | 11 +++++++----
lib/alloc_tag.c | 7 +++----
2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
index abd24016a900..62734244c0b9 100644
--- a/include/linux/alloc_tag.h
+++ b/include/linux/alloc_tag.h
@@ -18,6 +18,7 @@
struct alloc_tag_counters {
u64 bytes;
u64 calls;
+ u64 accu_calls;
};

/*
@@ -102,14 +103,15 @@ static inline bool mem_alloc_profiling_enabled(void)

static inline struct alloc_tag_counters alloc_tag_read(struct alloc_tag *tag)
{
- struct alloc_tag_counters v = { 0, 0 };
+ struct alloc_tag_counters v = { 0, 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;
+ counter = per_cpu_ptr(tag->counters, cpu);
+ v.bytes += counter->bytes;
+ v.calls += counter->calls;
+ v.accu_calls += counter->accu_calls;
}

return v;
@@ -145,6 +147,7 @@ static inline void __alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag
* counter because when we free each part the counter will be decremented.
*/
this_cpu_inc(tag->counters->calls);
+ this_cpu_inc(tag->counters->accu_calls);
}

static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag)
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 11ed973ac359..c4059362d828 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -66,8 +66,8 @@ static void allocinfo_stop(struct seq_file *m, void *arg)
static void print_allocinfo_header(struct seq_buf *buf)
{
/* Output format version, so we can change it. */
- seq_buf_printf(buf, "allocinfo - version: 1.0\n");
- seq_buf_printf(buf, "# <size> <calls> <tag info>\n");
+ seq_buf_printf(buf, "allocinfo - version: 1.1\n");
+ seq_buf_printf(buf, "# <size> <calls> <tag info> <accumulated calls>\n");
}

static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)
@@ -78,8 +78,7 @@ static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct)

seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls);
codetag_to_text(out, ct);
- seq_buf_putc(out, ' ');
- seq_buf_putc(out, '\n');
+ seq_buf_printf(out, " %llu\n", counter.accu_calls);
}

static int allocinfo_show(struct seq_file *m, void *arg)
--
2.39.2