Re: [PATCH 2/3] mm/vmalloc: extract vmap_insert_free_area helper

[Dev Jain]

On 15/09/26 7:55 am, Ye Liu wrote:
> 
> 
> 在 2026/9/15 01:02, Uladzislau Rezki 写道:
>> On Mon, Sep 14, 2026 at 11:34:01AM +0800, Ye Liu wrote:
>>> From: Ye Liu <liuye@xxxxxxxxxx>
>>>
>>> The allocation and insertion of a free vmap_area is duplicated
>>> between the loop body and the tail of vmap_init_free_space.  Factor
>>> it into a small helper so the main function only deals with computing
>>> the free gaps between busy regions.
>>>
>>> Signed-off-by: Ye Liu <liuye@xxxxxxxxxx>
>>> ---
>>>  mm/vmalloc.c | 41 ++++++++++++++++++-----------------------
>>>  1 file changed, 18 insertions(+), 23 deletions(-)
>>>
>>> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
>>> index 117483dd048c..797933ba9451 100644
>>> --- a/mm/vmalloc.c
>>> +++ b/mm/vmalloc.c
>>> @@ -5433,11 +5433,23 @@ module_init(proc_vmalloc_init);
>>>  
>>>  #endif
>>>  
>>> +static void __init vmap_insert_free_area(unsigned long start, unsigned long end)
>>> +{
>>> +	struct vmap_area *free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
>>> +
>>> +	if (!WARN_ON_ONCE(!free)) {
>>> +		free->va_start = start;
>>> +		free->va_end = end;
>>> +		insert_vmap_area_augment(free, NULL,
>>> +					 &free_vmap_area_root,
>>> +					 &free_vmap_area_list);
>>> +	}
>>> +}
>>> +
>>>  static void __init vmap_init_free_space(void)
>>>  {
>>>  	unsigned long vmap_start = 1;
>>>  	const unsigned long vmap_end = ULONG_MAX;
>>> -	struct vmap_area *free;
>>>  	struct vm_struct *busy;
>>>  
>>>  	/*
>>> @@ -5447,32 +5459,15 @@ static void __init vmap_init_free_space(void)
>>>  	 *  |<--------------------------------->|
>>>  	 */
>>>  	for (busy = vmlist; busy; busy = busy->next) {
>>> -		if ((unsigned long) busy->addr - vmap_start > 0) {
>>>
>> This line gets removed and then re-added below because of removing space
>> after (unsigned long). Maybe it is better to keep that space.
> However, the '{' is still there, but I'll add a space anyway.


Just mentioning in the commit message "while at it, drop redundant whitespace
in "(unsigned long) busy->addr" should suffice.

Reviewed-by: Dev Jain <dev.jain@xxxxxxx>