[PATCH] hugetlb: Add guard support

[PATCH] hugetlb: Add guard support

[Fushuai Wang]

Introduce guard support to simplify the usage of the
hugetlb_vma_{lock,unlock}_{read,write}.

Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
---
 include/linux/hugetlb.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 8e63e46b8e1f..f97cb2f123a3 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -15,6 +15,7 @@
 #include <linux/gfp.h>
 #include <linux/userfaultfd_k.h>
 #include <linux/nodemask.h>
+#include <linux/cleanup.h>
 
 struct ctl_table;
 struct user_struct;
@@ -468,6 +469,13 @@ static inline void hugetlb_split(struct vm_area_struct *vma, unsigned long addr)
 
 #endif /* !CONFIG_HUGETLB_PAGE */
 
+DEFINE_GUARD(hugetlb_vma_read, struct vm_area_struct *,
+	     hugetlb_vma_lock_read(_T), hugetlb_vma_unlock_read(_T))
+
+DEFINE_GUARD(hugetlb_vma_write, struct vm_area_struct *,
+	     hugetlb_vma_lock_write(_T), hugetlb_vma_unlock_write(_T))
+DEFINE_GUARD_COND(hugetlb_vma_write, _try, hugetlb_vma_trylock_write(_T))
+
 #ifndef pgd_write
 static inline int pgd_write(pgd_t pgd)
 {
-- 
2.36.1

Re: [PATCH] hugetlb: Add guard support

[David Hildenbrand (Red Hat)]

On 11/28/25 12:02, Fushuai Wang wrote:
> Introduce guard support to simplify the usage of the
> hugetlb_vma_{lock,unlock}_{read,write}.
> 
> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
> ---
>   include/linux/hugetlb.h | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 8e63e46b8e1f..f97cb2f123a3 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -15,6 +15,7 @@
>   #include <linux/gfp.h>
>   #include <linux/userfaultfd_k.h>
>   #include <linux/nodemask.h>
> +#include <linux/cleanup.h>
>   
>   struct ctl_table;
>   struct user_struct;
> @@ -468,6 +469,13 @@ static inline void hugetlb_split(struct vm_area_struct *vma, unsigned long addr)
>   
>   #endif /* !CONFIG_HUGETLB_PAGE */
>   
> +DEFINE_GUARD(hugetlb_vma_read, struct vm_area_struct *,
> +	     hugetlb_vma_lock_read(_T), hugetlb_vma_unlock_read(_T))
> +
> +DEFINE_GUARD(hugetlb_vma_write, struct vm_area_struct *,
> +	     hugetlb_vma_lock_write(_T), hugetlb_vma_unlock_write(_T))
> +DEFINE_GUARD_COND(hugetlb_vma_write, _try, hugetlb_vma_trylock_write(_T))

Do I understand correctly that the code you are introducing does not 
have any users?

-- 
Cheers

David

Re: [PATCH] hugetlb: Add guard support

[Fushuai Wang]

>>   include/linux/hugetlb.h | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>> 
>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>> index 8e63e46b8e1f..f97cb2f123a3 100644
>> --- a/include/linux/hugetlb.h
>> +++ b/include/linux/hugetlb.h
>> @@ -15,6 +15,7 @@
>>   #include <linux/gfp.h>
>>   #include <linux/userfaultfd_k.h>
>>   #include <linux/nodemask.h>
>> +#include <linux/cleanup.h>
>>   
>>   struct ctl_table;
>>   struct user_struct;
>> @@ -468,6 +469,13 @@ static inline void hugetlb_split(struct vm_area_struct *vma, unsigned long addr)
>>   
>>   #endif /* !CONFIG_HUGETLB_PAGE */
>>   
>> +DEFINE_GUARD(hugetlb_vma_read, struct vm_area_struct *,
>> +	     hugetlb_vma_lock_read(_T), hugetlb_vma_unlock_read(_T))
>> +
>> +DEFINE_GUARD(hugetlb_vma_write, struct vm_area_struct *,
>> +	     hugetlb_vma_lock_write(_T), hugetlb_vma_unlock_write(_T))
>> +DEFINE_GUARD_COND(hugetlb_vma_write, _try, hugetlb_vma_trylock_write(_T))
> 
> Do I understand correctly that the code you are introducing does not 
> have any users?

Yes, it is not used now, but it can be used in future development to simplify
the code. If there are complex hugetlb_vma locks in the current code, this can
also be used later to optimize them.

---
Regards,
Wang.

Re: [PATCH] hugetlb: Add guard support

[David Hildenbrand (Red Hat)]

On 11/28/25 12:23, Fushuai Wang wrote:
>>>    include/linux/hugetlb.h | 8 ++++++++
>>>    1 file changed, 8 insertions(+)
>>>
>>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>>> index 8e63e46b8e1f..f97cb2f123a3 100644
>>> --- a/include/linux/hugetlb.h
>>> +++ b/include/linux/hugetlb.h
>>> @@ -15,6 +15,7 @@
>>>    #include <linux/gfp.h>
>>>    #include <linux/userfaultfd_k.h>
>>>    #include <linux/nodemask.h>
>>> +#include <linux/cleanup.h>
>>>    
>>>    struct ctl_table;
>>>    struct user_struct;
>>> @@ -468,6 +469,13 @@ static inline void hugetlb_split(struct vm_area_struct *vma, unsigned long addr)
>>>    
>>>    #endif /* !CONFIG_HUGETLB_PAGE */
>>>    
>>> +DEFINE_GUARD(hugetlb_vma_read, struct vm_area_struct *,
>>> +	     hugetlb_vma_lock_read(_T), hugetlb_vma_unlock_read(_T))
>>> +
>>> +DEFINE_GUARD(hugetlb_vma_write, struct vm_area_struct *,
>>> +	     hugetlb_vma_lock_write(_T), hugetlb_vma_unlock_write(_T))
>>> +DEFINE_GUARD_COND(hugetlb_vma_write, _try, hugetlb_vma_trylock_write(_T))
>>
>> Do I understand correctly that the code you are introducing does not
>> have any users?
> 
> Yes, it is not used now, but it can be used in future development to simplify
> the code. If there are complex hugetlb_vma locks in the current code, this can
> also be used later to optimize them.

Right, but we usually don't add dead code. So it should ideally be 
introduced with actual users.
-- 
Cheers

David