Re: [External] Re: [PATCH v12 03/13] mm: Introduce VM_WARN_ON_PAGE macro

[Muchun Song]

On Thu, Jan 14, 2021 at 6:31 AM Mike Kravetz  wrote:
>
> On 1/6/21 6:19 AM, Muchun Song wrote:
> > Very similar to VM_WARN_ON_ONCE_PAGE and VM_BUG_ON_PAGE, add
> > VM_WARN_ON_PAGE macro.
> >
> > Signed-off-by: Muchun Song 
> > ---
> >  include/linux/mmdebug.h | 8 
> >  1 file changed, 8 insertions(+)
>
> I was going to question the use/need for this macro in the following
> patch.  Looks like Oscar has already done that, and free_bootmem_page
> will now use VM_BUG_ON_PAGE.  So, this patch can be dropped.

In the previous version, Oscar suggested I use WARN_ON instead of
BUG_ON. But he realised we actually should use BUG_ON in this
version. So I will drop this in the next version. Thanks.

>
> --
> Mike Kravetz

Re: [PATCH v12 03/13] mm: Introduce VM_WARN_ON_PAGE macro

[Mike Kravetz]

On 1/6/21 6:19 AM, Muchun Song wrote:
> Very similar to VM_WARN_ON_ONCE_PAGE and VM_BUG_ON_PAGE, add
> VM_WARN_ON_PAGE macro.
> 
> Signed-off-by: Muchun Song 
> ---
>  include/linux/mmdebug.h | 8 
>  1 file changed, 8 insertions(+)

I was going to question the use/need for this macro in the following
patch.  Looks like Oscar has already done that, and free_bootmem_page
will now use VM_BUG_ON_PAGE.  So, this patch can be dropped.

-- 
Mike Kravetz

[PATCH v12 03/13] mm: Introduce VM_WARN_ON_PAGE macro

[Muchun Song]

Very similar to VM_WARN_ON_ONCE_PAGE and VM_BUG_ON_PAGE, add
VM_WARN_ON_PAGE macro.

Signed-off-by: Muchun Song 
---
 include/linux/mmdebug.h | 8 
 1 file changed, 8 insertions(+)

diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h
index 5d0767cb424a..eff5b13a6945 100644
--- a/include/linux/mmdebug.h
+++ b/include/linux/mmdebug.h
@@ -37,6 +37,13 @@ void dump_mm(const struct mm_struct *mm);
BUG();  \
}   \
} while (0)
+#define VM_WARN_ON_PAGE(cond, page)\
+   do {\
+   if (unlikely(cond)) {   \
+   dump_page(page, "VM_WARN_ON_PAGE(" 
__stringify(cond)")");\
+   WARN_ON(1); \
+   }   \
+   } while (0)
 #define VM_WARN_ON_ONCE_PAGE(cond, page)   ({  \
static bool __section(".data.once") __warned;   \
int __ret_warn_once = !!(cond); \
@@ -60,6 +67,7 @@ void dump_mm(const struct mm_struct *mm);
 #define VM_BUG_ON_MM(cond, mm) VM_BUG_ON(cond)
 #define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
+#define VM_WARN_ON_PAGE(cond, page) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ON_ONCE_PAGE(cond, page)  BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond)
 #define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond)
-- 
2.11.0