On Tue 21-12-21 21:24:57, Shakeel Butt wrote:
> The kvmalloc* allocation functions can fallback to vmalloc allocations
> and more often on long running machines. In addition the kernel does
> have __GFP_ACCOUNT kvmalloc* calls. So, often on long running machines,
> the memory.stat does not tell the complete picture which type of memory
> is charged to the memcg. So add a per-memcg vmalloc stat.
>
> Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
The counter is useful IMHO. I just have one implementation specific
question.
[...]
> @@ -2626,6 +2627,9 @@ static void __vunmap(const void *addr, int deallocate_pages)
> unsigned int page_order = vm_area_page_order(area);
> int i;
>
> + mod_memcg_page_state(area->pages[0], MEMCG_VMALLOC,
> + -(int)area->nr_pages);
> +
> for (i = 0; i < area->nr_pages; i += 1U << page_order) {
> struct page *page = area->pages[i];
>
> @@ -2964,6 +2968,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
> page_order, nr_small_pages, area->pages);
>
> atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
> + mod_memcg_page_state(area->pages[0], MEMCG_VMALLOC, area->nr_pages);
>
> /*
> * If not enough pages were obtained to accomplish an
Is it safe to assume that the whole area is always charged to the same
memcg? I am not really deeply familiar with vmalloc internals but is it
possible that an area could get resized/partially reused with a
different charging context?
A clarification comment would be really handy.
--
Michal Hocko
SUSE Labs
