Re: [PATCH v4 4/6] alloc_tag: add accuracy based filtering to ioctl

[Hao Ge <hao.ge@linux.dev>]

On 2026/6/10 08:12, Abhishek Bapat wrote:
> Extend the allocinfo filtering mechanism to allow users to filter tags
> based on their accuracy.
>
> Signed-off-by: Abhishek Bapat <abhishekbapat@google.com>


Acked-by: Hao Ge <hao.ge@linux.dev>


> ---
>   include/uapi/linux/alloc_tag.h | 4 ++++
>   lib/alloc_tag.c                | 8 ++++++++
>   2 files changed, 12 insertions(+)
>
> diff --git a/include/uapi/linux/alloc_tag.h b/include/uapi/linux/alloc_tag.h
> index 7f5acbb44c14..6ea39c4869fe 100644
> --- a/include/uapi/linux/alloc_tag.h
> +++ b/include/uapi/linux/alloc_tag.h
> @@ -26,6 +26,8 @@ struct allocinfo_tag {
>   	char function[ALLOCINFO_STR_SIZE];
>   	char filename[ALLOCINFO_STR_SIZE];
>   	__u64 lineno;
> +	/* filter criteria only; see allocinfo_counter.accurate for actual accuracy */
> +	__u64 inaccurate;
>   };
>   
>   /* The alignment ensures 32-bit compatible interfaces are not broken */
> @@ -45,6 +47,7 @@ enum {
>   	ALLOCINFO_FILTER_FUNCTION,
>   	ALLOCINFO_FILTER_FILENAME,
>   	ALLOCINFO_FILTER_LINENO,
> +	ALLOCINFO_FILTER_INACCURATE,
>   	ALLOCINFO_FILTER_MIN_SIZE,
>   	ALLOCINFO_FILTER_MAX_SIZE,
>   	__ALLOCINFO_FILTER_LAST = ALLOCINFO_FILTER_MAX_SIZE
> @@ -54,6 +57,7 @@ enum {
>   #define ALLOCINFO_FILTER_MASK_FUNCTION		(1 << ALLOCINFO_FILTER_FUNCTION)
>   #define ALLOCINFO_FILTER_MASK_FILENAME		(1 << ALLOCINFO_FILTER_FILENAME)
>   #define ALLOCINFO_FILTER_MASK_LINENO		(1 << ALLOCINFO_FILTER_LINENO)
> +#define ALLOCINFO_FILTER_MASK_INACCURATE	(1 << ALLOCINFO_FILTER_INACCURATE)
>   #define ALLOCINFO_FILTER_MASK_MIN_SIZE		(1 << ALLOCINFO_FILTER_MIN_SIZE)
>   #define ALLOCINFO_FILTER_MASK_MAX_SIZE		(1 << ALLOCINFO_FILTER_MAX_SIZE)
>   
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index a936cf18611a..73fb3d0ab821 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -249,6 +249,8 @@ static bool matches_filter(struct codetag *ct, struct allocinfo_filter *filter,
>   			   struct alloc_tag_counters *counters,
>   			   bool *fetched_counters)
>   {
> +	bool inaccurate;
> +
>   	if (!filter || !filter->mask)
>   		return true;
>   
> @@ -274,6 +276,12 @@ static bool matches_filter(struct codetag *ct, struct allocinfo_filter *filter,
>   	    ct->lineno != filter->fields.lineno)
>   		return false;
>   
> +	if (filter->mask & ALLOCINFO_FILTER_MASK_INACCURATE) {
> +		inaccurate = !!(ct->flags & CODETAG_FLAG_INACCURATE);
> +		if (inaccurate != !!(filter->fields.inaccurate))
> +			return false;
> +	}
> +
>   	if (filter->mask & (ALLOCINFO_FILTER_MASK_MIN_SIZE | ALLOCINFO_FILTER_MASK_MAX_SIZE)) {
>   		if (!*fetched_counters) {
>   			*counters = allocinfo_prefetch_counters(ct);