Re: [PATCH v4 31/36] lib: add memory allocations report in show_mem()

[Vlastimil Babka]

On 2/21/24 20:40, Suren Baghdasaryan wrote:
> Include allocations in show_mem reports.
> 
> Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>

Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>

Nit: there's pr_notice() that's shorter than printk(KERN_NOTICE

> ---
>  include/linux/alloc_tag.h |  7 +++++++
>  include/linux/codetag.h   |  1 +
>  lib/alloc_tag.c           | 38 ++++++++++++++++++++++++++++++++++++++
>  lib/codetag.c             |  5 +++++
>  mm/show_mem.c             | 26 ++++++++++++++++++++++++++
>  5 files changed, 77 insertions(+)
> 
> diff --git a/include/linux/alloc_tag.h b/include/linux/alloc_tag.h
> index 29636719b276..85a24a027403 100644
> --- a/include/linux/alloc_tag.h
> +++ b/include/linux/alloc_tag.h
> @@ -30,6 +30,13 @@ 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);
> diff --git a/include/linux/codetag.h b/include/linux/codetag.h
> index bfd0ba5c4185..c2a579ccd455 100644
> --- a/include/linux/codetag.h
> +++ b/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);
>  
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index cb5adec4b2e2..ec54f29482dc 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -86,6 +86,44 @@ 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);
> diff --git a/lib/codetag.c b/lib/codetag.c
> index b13412ca57cc..7b39cec9648a 100644
> --- a/lib/codetag.c
> +++ b/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 = {
> diff --git a/mm/show_mem.c b/mm/show_mem.c
> index 8dcfafbd283c..1e41f8d6e297 100644
> --- a/mm/show_mem.c
> +++ b/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) {
> +			printk(KERN_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)
> +					printk(KERN_NOTICE "%12lli %8llu %s:%u [%s] func:%s\n",
> +					       counter.bytes, counter.calls, ct->filename,
> +					       ct->lineno, ct->modname, ct->function);
> +				else
> +					printk(KERN_NOTICE "%12lli %8llu %s:%u func:%s\n",
> +					       counter.bytes, counter.calls, ct->filename,
> +					       ct->lineno, ct->function);
> +			}
> +		}
> +	}
> +#endif
>  }