On Fri, Jun 17, 2016 at 1:55 PM, Josh Poimboeuf <[email protected]> wrote: > On Fri, Jun 17, 2016 at 01:00:41PM -0700, Andy Lutomirski wrote: >> We should account for stacks regardless of stack size. Move it into >> account_kernel_stack. >> >> Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 >> memory.stat") >> Cc: Vladimir Davydov <[email protected]> >> Cc: Johannes Weiner <[email protected]> >> Cc: Michal Hocko <[email protected]> >> Cc: [email protected] >> Signed-off-by: Andy Lutomirski <[email protected]> >> --- >> kernel/fork.c | 15 ++++++--------- >> 1 file changed, 6 insertions(+), 9 deletions(-) >> >> diff --git a/kernel/fork.c b/kernel/fork.c >> index be7f006af727..cd2abe6e4e41 100644 >> --- a/kernel/fork.c >> +++ b/kernel/fork.c >> @@ -165,20 +165,12 @@ static struct thread_info >> *alloc_thread_info_node(struct task_struct *tsk, >> struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP, >> THREAD_SIZE_ORDER); >> >> - if (page) >> - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, >> - 1 << THREAD_SIZE_ORDER); >> - >> return page ? page_address(page) : NULL; >> } >> >> static inline void free_thread_info(struct thread_info *ti) >> { >> - struct page *page = virt_to_page(ti); >> - >> - memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK, >> - -(1 << THREAD_SIZE_ORDER)); >> - __free_kmem_pages(page, THREAD_SIZE_ORDER); >> + free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER); >> } >> # else >> static struct kmem_cache *thread_info_cache; >> @@ -227,6 +219,11 @@ static void account_kernel_stack(struct thread_info >> *ti, int account) >> >> mod_zone_page_state(zone, NR_KERNEL_STACK_KB, >> THREAD_SIZE / 1024 * account); >> + >> + /* All stack pages belong to the same memcg. */ >> + memcg_kmem_update_page_stat( >> + virt_to_page(ti), MEMCG_KERNEL_STACK, >> + account * (THREAD_SIZE / PAGE_SIZE)); >> } > > Won't this be broken in the case where THREAD_SIZE < PAGE_SIZE?
In my defense, it was broken before this change, too. Sigh. I'll change this to count in KiB too. As far as I can tell, this thing is used for display only. --Andy
