mm: account pud page tables
On a machine with 5-level paging support a process can allocate
significant amount of memory and stay unnoticed by oom-killer and memory
cgroup. The trick is to allocate a lot of PUD page tables. We don't
account PUD page tables, only PMD and PTE.
We already addressed the same issue for PMD page tables, see commit
dc6c9a35b66b ("mm: account pmd page tables to the process").
Introduction of 5-level paging brings the same issue for PUD page
tables.
The patch expands accounting to PUD level.
[kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/]
Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com
[heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting]
Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/debug.c b/mm/debug.c
index 6726bec..a12d826b 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -105,7 +105,8 @@
"get_unmapped_area %p\n"
#endif
"mmap_base %lu mmap_legacy_base %lu highest_vm_end %lu\n"
- "pgd %p mm_users %d mm_count %d nr_ptes %lu nr_pmds %lu map_count %d\n"
+ "pgd %p mm_users %d mm_count %d\n"
+ "nr_ptes %lu nr_pmds %lu nr_puds %lu map_count %d\n"
"hiwater_rss %lx hiwater_vm %lx total_vm %lx locked_vm %lx\n"
"pinned_vm %lx data_vm %lx exec_vm %lx stack_vm %lx\n"
"start_code %lx end_code %lx start_data %lx end_data %lx\n"
@@ -136,7 +137,8 @@
mm->pgd, atomic_read(&mm->mm_users),
atomic_read(&mm->mm_count),
atomic_long_read((atomic_long_t *)&mm->nr_ptes),
- mm_nr_pmds((struct mm_struct *)mm),
+ mm_nr_pmds(mm),
+ mm_nr_puds(mm),
mm->map_count,
mm->hiwater_rss, mm->hiwater_vm, mm->total_vm, mm->locked_vm,
mm->pinned_vm, mm->data_vm, mm->exec_vm, mm->stack_vm,
diff --git a/mm/memory.c b/mm/memory.c
index 42fb303..6bbd407 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -506,6 +506,7 @@
pud = pud_offset(p4d, start);
p4d_clear(p4d);
pud_free_tlb(tlb, pud, start);
+ mm_dec_nr_puds(tlb->mm);
}
static inline void free_p4d_range(struct mmu_gather *tlb, pgd_t *pgd,
@@ -4149,15 +4150,17 @@
spin_lock(&mm->page_table_lock);
#ifndef __ARCH_HAS_5LEVEL_HACK
- if (p4d_present(*p4d)) /* Another has populated it */
- pud_free(mm, new);
- else
+ if (!p4d_present(*p4d)) {
+ mm_inc_nr_puds(mm);
p4d_populate(mm, p4d, new);
-#else
- if (pgd_present(*p4d)) /* Another has populated it */
+ } else /* Another has populated it */
pud_free(mm, new);
- else
+#else
+ if (!pgd_present(*p4d)) {
+ mm_inc_nr_puds(mm);
pgd_populate(mm, p4d, new);
+ } else /* Another has populated it */
+ pud_free(mm, new);
#endif /* __ARCH_HAS_5LEVEL_HACK */
spin_unlock(&mm->page_table_lock);
return 0;
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 3023919..f642a45 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -221,7 +221,8 @@
* task's rss, pagetable and swap space use.
*/
points = get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS) +
- atomic_long_read(&p->mm->nr_ptes) + mm_nr_pmds(p->mm);
+ atomic_long_read(&p->mm->nr_ptes) + mm_nr_pmds(p->mm) +
+ mm_nr_puds(p->mm);
task_unlock(p);
/*
@@ -397,7 +398,7 @@
struct task_struct *p;
struct task_struct *task;
- pr_info("[ pid ] uid tgid total_vm rss nr_ptes nr_pmds swapents oom_score_adj name\n");
+ pr_info("[ pid ] uid tgid total_vm rss nr_ptes nr_pmds nr_puds swapents oom_score_adj name\n");
rcu_read_lock();
for_each_process(p) {
if (oom_unkillable_task(p, memcg, nodemask))
@@ -413,11 +414,12 @@
continue;
}
- pr_info("[%5d] %5d %5d %8lu %8lu %7ld %7ld %8lu %5hd %s\n",
+ pr_info("[%5d] %5d %5d %8lu %8lu %7ld %7ld %7ld %8lu %5hd %s\n",
task->pid, from_kuid(&init_user_ns, task_uid(task)),
task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
atomic_long_read(&task->mm->nr_ptes),
mm_nr_pmds(task->mm),
+ mm_nr_puds(task->mm),
get_mm_counter(task->mm, MM_SWAPENTS),
task->signal->oom_score_adj, task->comm);
task_unlock(task);