On Wed, Dec 18, 2024 at 4:49 AM David Wang <00107082@xxxxxxx> wrote: > > Hi, > > I found another usage/benefit for accumulative counters: > > On my system, /proc/allocinfo yields about 5065 lines, of which 2/3 lines have accumulative counter *0*. > meaning no memory activities. (right?) > It is quite a waste to keep those items which are *not alive yet*. > With additional changes, only 1684 lines in /proc/allocinfo on my system: > > --- a/lib/alloc_tag.c > +++ b/lib/alloc_tag.c > @@ -95,8 +95,11 @@ static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct) > struct alloc_tag_counters counter = alloc_tag_read(tag); > s64 bytes = counter.bytes; > > + if (counter.accu_calls == 0) > + return; > seq_buf_printf(out, "%12lli %8llu ", bytes, counter.calls); > > > I think this is quite an improvement worth pursuing. > (counter.calls could also be used to filter out "inactive" items, but > lines keep disappearing/reappearing can confuse monitoring systems.) Please see discussion at https://lore.kernel.org/all/20241211085616.2471901-1-quic_zhenhuah@xxxxxxxxxxx/ > > > Thanks~ > David > > > At 2024-09-13 13:57:29, "David Wang" <00107082@xxxxxxx> wrote: > >Accumulative allocation counter can be used to evaluate > >memory allocation behavior/rate via delta(counters)/delta(time). > >It can help analysis performance issues, identify top modules > >with high rate of memory allocation activity. > >Considering this would incur extra performance and memory impact, > >introduce kconfig MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER. > > > >Signed-off-by: David Wang <00107082@xxxxxxx> > >--- > >Changes in v2: > >- Add kconfig MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER as > >suggested by "Kent Overstreet <kent.overstreet@xxxxxxxxx>" > > > >--- > > include/linux/alloc_tag.h | 18 +++++++++++++++--- > > lib/Kconfig.debug | 10 ++++++++++ > > lib/alloc_tag.c | 10 +++++++++- > > 3 files changed, 34 insertions(+), 4 deletions(-) > > > >diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h > >index 8c61ccd161ba..5a94d61205b5 100644 > >--- a/include/linux/alloc_tag.h > >+++ b/include/linux/alloc_tag.h > >@@ -18,6 +18,9 @@ > > struct alloc_tag_counters { > > u64 bytes; > > u64 calls; > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ u64 accu_calls; > >+#endif > > }; > > > > /* > >@@ -103,13 +106,19 @@ 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 }; > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ v.accu_calls = 0; > >+#endif > > 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; > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ v.accu_calls += counter->accu_calls; > >+#endif > > } > > > > return v; > >@@ -145,6 +154,9 @@ 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); > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ this_cpu_inc(tag->counters->accu_calls); > >+#endif > > } > > > > static inline void alloc_tag_ref_set(union codetag_ref *ref, struct alloc_tag *tag) > >diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > >index a30c03a66172..1e9974d28510 100644 > >--- a/lib/Kconfig.debug > >+++ b/lib/Kconfig.debug > >@@ -1000,6 +1000,16 @@ config MEM_ALLOC_PROFILING_DEBUG > > Adds warnings with helpful error messages for memory allocation > > profiling. > > > >+config MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ bool "Enable accumulative allocation counters" > >+ default n > >+ depends on MEM_ALLOC_PROFILING > >+ help > >+ Record accumulative call counters for memory allocation. This may have > >+ extra performance and memory impact, but the impact is small. > >+ The stat can be used to evaluate allocation activity/rate > >+ via delta(counter)/delta(time). > >+ > > source "lib/Kconfig.kasan" > > source "lib/Kconfig.kfence" > > source "lib/Kconfig.kmsan" > >diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c > >index 81e5f9a70f22..6b03edb04e7d 100644 > >--- a/lib/alloc_tag.c > >+++ b/lib/alloc_tag.c > >@@ -66,8 +66,12 @@ 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, "allocinfo - version: 1.1\n"); > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ seq_buf_printf(buf, "# <size> <calls> <tag info> <accumulative calls>\n"); > >+#else > > seq_buf_printf(buf, "# <size> <calls> <tag info>\n"); > >+#endif > > } > > > > static void alloc_tag_to_text(struct seq_buf *out, struct codetag *ct) > >@@ -78,8 +82,12 @@ 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); > >+#ifdef CONFIG_MEM_ALLOC_PROFILING_ACCUMULATIVE_CALL_COUNTER > >+ seq_buf_printf(out, " %llu\n", counter.accu_calls); > >+#else > > seq_buf_putc(out, ' '); > > seq_buf_putc(out, '\n'); > >+#endif > > } > > > > static int allocinfo_show(struct seq_file *m, void *arg) > >-- > >2.39.2
