Re: [PATCH v2 1/3] mm/page_owner: add filter infrastructure

["zhen.ni" <zhen.ni@easystack.cn>]

在 2026/4/27 23:35, Zi Yan 写道:
> On 19 Apr 2026, at 11:55, Zhen Ni wrote:
> 
>> Add data structure for page_owner filtering functionality and create
>> debugfs directory for filter controls.
>>
>> This adds:
>> - enum page_owner_print_mode with values for full_stack and stack_handle
>> - struct page_owner_filter with print_mode and nid_mask fields
>> - Static owner_filter instance initialized with default values
>> - page_owner_filter debugfs directory
>>
>> The filter infrastructure will be used to add print_mode and NUMA node
>> filtering capabilities in subsequent commits.
>>
>> Link: https://lore.kernel.org/linux-mm/20260417154638.22370-2-zhen.ni@easystack.cn/
>> Suggested-by: Zi Yan <ziy@nvidia.com>
>> Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
>> ---
>>
>> Changes in v2:
>> - Use enum page_owner_print_mode instead of bool 'compact' for better clarity
>> - Use nodemask_t instead of int 'nid' to support multi-node filtering
>> ---
>>   mm/page_owner.c | 20 +++++++++++++++++++-
>>   1 file changed, 19 insertions(+), 1 deletion(-)
> 
> The patch can be folded into Patch 2. Otherwise, these new types are not
> used and page_owner_filter folder is just empty.
> 


Thanks for your review and suggestion.

I kept the 3-patch structure mainly for clear functional separation,
which also makes review easier. Patch 1 adds the infrastructure,
patch 2 adds print_mode filter, and patch 3 adds NUMA filter.

I discussed this with Andrew and he has already accepted the
current 3-patch structure into mm-new for testing. Since he's okay
with it and mentioned that bisection holes are acceptable in this
case, I'll keep the current structure in v3.

>>
>> diff --git a/mm/page_owner.c b/mm/page_owner.c
>> index 8178e0be557f..5884d883837e 100644
>> --- a/mm/page_owner.c
>> +++ b/mm/page_owner.c
>> @@ -54,6 +54,21 @@ struct stack_print_ctx {
>>   	u8 flags;
>>   };
>>
>> +enum page_owner_print_mode {
>> +	PAGE_OWNER_PRINT_FULL_STACK,
>> +	PAGE_OWNER_PRINT_STACK_HANDLE,
>> +};
>> +
>> +struct page_owner_filter {
>> +	enum page_owner_print_mode print_mode;
>> +	nodemask_t nid_mask;
>> +};
>> +
>> +static struct page_owner_filter owner_filter = {
>> +	.print_mode = PAGE_OWNER_PRINT_FULL_STACK,
>> +	.nid_mask = NODE_MASK_NONE,
>> +};
>> +
>>   static bool page_owner_enabled __initdata;
>>   DEFINE_STATIC_KEY_FALSE(page_owner_inited);
>>
>> @@ -973,7 +988,7 @@ DEFINE_SIMPLE_ATTRIBUTE(page_owner_threshold_fops, &page_owner_threshold_get,
>>
>>   static int __init pageowner_init(void)
>>   {
>> -	struct dentry *dir;
>> +	struct dentry *dir, *filter_dir;
>>
>>   	if (!static_branch_unlikely(&page_owner_inited)) {
>>   		pr_info("page_owner is disabled\n");
>> @@ -981,6 +996,9 @@ static int __init pageowner_init(void)
>>   	}
>>
>>   	debugfs_create_file("page_owner", 0400, NULL, NULL, &page_owner_fops);
>> +
>> +	filter_dir = debugfs_create_dir("page_owner_filter", NULL);
>> +
>>   	dir = debugfs_create_dir("page_owner_stacks", NULL);
>>   	debugfs_create_file("show_stacks", 0400, dir,
>>   			    (void *)(STACK_PRINT_FLAG_STACK |
>> -- 
>> 2.20.1
> 
> 
> Best Regards,
> Yan, Zi
> 
> 
Best regards,
Zhen