Re: [PATCH v3 4/6] mm: cma: add __cma_release()

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2025/10/14 3:48, David Hildenbrand wrote:
> On 13.10.25 15:38, Kefeng Wang wrote:
>> Kill cma_pages_valid() which only used in cma_release(), also
>> cleanup code duplication between cma pages valid checking and
>> cma memrange finding, add __cma_release() helper to prepare for
>> the upcoming frozen page release.
>>
>> Reviewed-by: Jane Chu <jane.chu@oracle.com>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>>   include/linux/cma.h |  1 -
>>   mm/cma.c            | 62 +++++++++++++++------------------------------
>>   2 files changed, 21 insertions(+), 42 deletions(-)
>>
>> diff --git a/include/linux/cma.h b/include/linux/cma.h
>> index 62d9c1cf6326..e5745d2aec55 100644
>> --- a/include/linux/cma.h
>> +++ b/include/linux/cma.h
>> @@ -49,7 +49,6 @@ extern int cma_init_reserved_mem(phys_addr_t base, 
>> phys_addr_t size,
>>                       struct cma **res_cma);
>>   extern struct page *cma_alloc(struct cma *cma, unsigned long count, 
>> unsigned int align,
>>                     bool no_warn);
>> -extern bool cma_pages_valid(struct cma *cma, const struct page 
>> *pages, unsigned long count);
>>   extern bool cma_release(struct cma *cma, const struct page *pages, 
>> unsigned long count);
>>   extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), 
>> void *data);
>> diff --git a/mm/cma.c b/mm/cma.c
>> index 813e6dc7b095..88016f4aef7f 100644
>> --- a/mm/cma.c
>> +++ b/mm/cma.c
>> @@ -942,34 +942,43 @@ struct folio *cma_alloc_folio(struct cma *cma, 
>> int order, gfp_t gfp)
>>       return page ? page_folio(page) : NULL;
>>   }
>> -bool cma_pages_valid(struct cma *cma, const struct page *pages,
>> -             unsigned long count)
>> +static bool __cma_release(struct cma *cma, const struct page *pages,
>> +              unsigned long count)
>>   {
>>       unsigned long pfn, end;
>>       int r;
>>       struct cma_memrange *cmr;
>> -    bool ret;
>> +
>> +    pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, 
>> count);
>>       if (!cma || !pages || count > cma->count)
>>           return false;
>>       pfn = page_to_pfn(pages);
>> -    ret = false;
>>       for (r = 0; r < cma->nranges; r++) {
>>           cmr = &cma->ranges[r];
>>           end = cmr->base_pfn + cmr->count;
>>           if (pfn >= cmr->base_pfn && pfn < end) {
>> -            ret = pfn + count <= end;
>> -            break;
>> +            if (pfn + count <= end)
>> +                break;
>> +
>> +            VM_WARN_ON_ONCE(1);
>>           }
>>       }
>> -    if (!ret)
>> -        pr_debug("%s(page %p, count %lu)\n",
>> -                __func__, (void *)pages, count);
>> +    if (r == cma->nranges) {
>> +        pr_debug("%s(no cma range match the page %p)\n",
>>
> 
> ".. matches the page range ..." ?

Yeah，will update， thanks
> 
> With that
> 
> Acked-by: David Hildenbrand <david@redhat.com>
>