On 2/14/24 18:01, Oscar Salvador wrote:
> We want to be able to filter out the stacks based on a threshold we can
> can tune.
> By writing to 'count_threshold' file, we can adjust the threshold value.
>
> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
...
> ---
> mm/page_owner.c | 29 +++++++++++++++++++++++++----
> 1 file changed, 25 insertions(+), 4 deletions(-)
>
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index 5258a417f4d1..9b975f59b773 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -846,9 +846,11 @@ static void *stack_next(struct seq_file *m, void *v, loff_t *ppos)
> return stack;
> }
>
> +static unsigned long page_owner_stack_threshold;
> +
> static int stack_print(struct seq_file *m, void *v)
> {
> - int i;
> + int i, stack_count;
> struct stack *stack = v;
> unsigned long *entries;
> unsigned long nr_entries;
> @@ -856,14 +858,15 @@ static int stack_print(struct seq_file *m, void *v)
>
> nr_entries = stack_record->size;
> entries = stack_record->entries;
> + stack_count = refcount_read(&stack_record->count);
Again "- 1" here.
> - if (!nr_entries || nr_entries < 0 ||
> - refcount_read(&stack_record->count) < 2)
> + if (!nr_entries || nr_entries < 0 || stack_count < 2 ||
> + stack_count < page_owner_stack_threshold)
Which will also correct the comparison.
> return 0;
>
> for (i = 0; i < nr_entries; i++)
> seq_printf(m, " %pS\n", (void *)entries[i]);
> - seq_printf(m, "stack_count: %d\n\n", refcount_read(&stack_record->count));
> + seq_printf(m, "stack_count: %d\n\n", stack_count);
And no - 1 needed here then.
