2023-01-13 03:29:18

by Baoquan He

Subject: [PATCH v3 4/7] mm/vmalloc: explicitly identify vm_map_ram area when shown in /proc/vmcoreinfo

Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, we can
clearly differentiate it with other vmalloc areas. So identify
vm_map_area area by checking VMAP_RAM of vmap_area->flags when shown
in /proc/vmcoreinfo.

Meanwhile, the code comment above vm_map_ram area checking in s_show()
is not needed any more, remove it here.

Signed-off-by: Baoquan He <[email protected]>
---
mm/vmalloc.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 13875bc41e27..4a10b3b692fa 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4225,11 +4225,7 @@ static int s_show(struct seq_file *m, void *p)

va = list_entry(p, struct vmap_area, list);

- /*
- * s_show can encounter race with remove_vm_area, !vm on behalf
- * of vmap area is being tear down or vm_map_ram allocation.
- */
- if (!va->vm) {
+ if (!va->vm && (va->flags & VMAP_RAM)) {
seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
(void *)va->va_start, (void *)va->va_end,
va->va_end - va->va_start);
--
2.34.1

2023-01-16 12:57:34

by Uladzislau Rezki

Subject: Re: [PATCH v3 4/7] mm/vmalloc: explicitly identify vm_map_ram area when shown in /proc/vmcoreinfo

On Fri, Jan 13, 2023 at 11:19:18AM +0800, Baoquan He wrote:
> Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, we can
> clearly differentiate it with other vmalloc areas. So identify
> vm_map_area area by checking VMAP_RAM of vmap_area->flags when shown
> in /proc/vmcoreinfo.
>
> Meanwhile, the code comment above vm_map_ram area checking in s_show()
> is not needed any more, remove it here.
>
> Signed-off-by: Baoquan He <[email protected]>
> ---
> mm/vmalloc.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 13875bc41e27..4a10b3b692fa 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4225,11 +4225,7 @@ static int s_show(struct seq_file *m, void *p)
>
> va = list_entry(p, struct vmap_area, list);
>
> - /*
> - * s_show can encounter race with remove_vm_area, !vm on behalf
> - * of vmap area is being tear down or vm_map_ram allocation.
> - */
> - if (!va->vm) {
> + if (!va->vm && (va->flags & VMAP_RAM)) {
> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
> (void *)va->va_start, (void *)va->va_end,
> va->va_end - va->va_start);
> --
> 2.34.1
>
Reviewed-by: Uladzislau Rezki (Sony) <[email protected]>

--
Uladzislau Rezki

2023-01-16 13:09:15

by Lorenzo Stoakes

Subject: Re: [PATCH v3 4/7] mm/vmalloc: explicitly identify vm_map_ram area when shown in /proc/vmcoreinfo

On Fri, Jan 13, 2023 at 11:19:18AM +0800, Baoquan He wrote:
> Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, we can
> clearly differentiate it with other vmalloc areas. So identify
> vm_map_area area by checking VMAP_RAM of vmap_area->flags when shown
> in /proc/vmcoreinfo.
>
> Meanwhile, the code comment above vm_map_ram area checking in s_show()
> is not needed any more, remove it here.
>
> Signed-off-by: Baoquan He <[email protected]>
> ---
> mm/vmalloc.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 13875bc41e27..4a10b3b692fa 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4225,11 +4225,7 @@ static int s_show(struct seq_file *m, void *p)
>
> va = list_entry(p, struct vmap_area, list);
>
> - /*
> - * s_show can encounter race with remove_vm_area, !vm on behalf
> - * of vmap area is being tear down or vm_map_ram allocation.
> - */
> - if (!va->vm) {
> + if (!va->vm && (va->flags & VMAP_RAM)) {
> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
> (void *)va->va_start, (void *)va->va_end,
> va->va_end - va->va_start);
> --
> 2.34.1
>

Reviewed-by: Lorenzo Stoakes <[email protected]>