memcg: add per-memcg vmalloc stat

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.

[shakeelb@google.com: page_memcg() within rcu lock, per Muchun]
Link: https://lkml.kernel.org/r/20211222052457.1960701-1-shakeelb@google.com
[akpm@linux-foundation.org: remove cast, per Muchun]
[shakeelb@google.com: remove area->page[0] checks and move to page by page accounting per Michal]
Link: https://lkml.kernel.org/r/20220104222341.3972772-1-shakeelb@google.com
Link: https://lkml.kernel.org/r/20211221215336.1922823-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 8269bfa..4f400b0 100644 (file)
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1314,6 +1314,9 @@ PAGE_SIZE multiple when read back.
          sock (npn)
                Amount of memory used in network transmission buffers
 
+         vmalloc (npn)
+               Amount of memory used for vmap backed memory.
+
          shmem
                Amount of cached filesystem data that is swap-backed,
                such as tmpfs, shm segments, shared anonymous mmap()s

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 951f24f..0131e55 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -33,6 +33,7 @@ enum memcg_stat_item {
        MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
        MEMCG_SOCK,
        MEMCG_PERCPU_B,
+       MEMCG_VMALLOC,
        MEMCG_NR_STAT,
 };
 
@@ -992,6 +993,21 @@ static inline void mod_memcg_state(struct mem_cgroup *memcg,
        local_irq_restore(flags);
 }
 
+static inline void mod_memcg_page_state(struct page *page,
+                                       int idx, int val)
+{
+       struct mem_cgroup *memcg;
+
+       if (mem_cgroup_disabled())
+               return;
+
+       rcu_read_lock();
+       memcg = page_memcg(page);
+       if (memcg)
+               mod_memcg_state(memcg, idx, val);
+       rcu_read_unlock();
+}
+
 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
 {
        return READ_ONCE(memcg->vmstats.state[idx]);
@@ -1447,6 +1463,11 @@ static inline void mod_memcg_state(struct mem_cgroup *memcg,
 {
 }
 
+static inline void mod_memcg_page_state(struct page *page,
+                                       int idx, int val)
+{
+}
+
 static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
 {
        return 0;

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 88e1be9..c9ddd02 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1375,6 +1375,7 @@ static const struct memory_stat memory_stats[] = {
        { "pagetables",                 NR_PAGETABLE                    },
        { "percpu",                     MEMCG_PERCPU_B                  },
        { "sock",                       MEMCG_SOCK                      },
+       { "vmalloc",                    MEMCG_VMALLOC                   },
        { "shmem",                      NR_SHMEM                        },
        { "file_mapped",                NR_FILE_MAPPED                  },
        { "file_dirty",                 NR_FILE_DIRTY                   },

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index bf3c2fe..80c6de4 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -31,6 +31,7 @@
 #include <linux/kmemleak.h>
 #include <linux/atomic.h>
 #include <linux/compiler.h>
+#include <linux/memcontrol.h>
 #include <linux/llist.h>
 #include <linux/bitops.h>
 #include <linux/rbtree_augmented.h>
@@ -2623,12 +2624,13 @@ static void __vunmap(const void *addr, int deallocate_pages)
 
        if (deallocate_pages) {
                unsigned int page_order = vm_area_page_order(area);
-               int i;
+               int i, step = 1U << page_order;
 
-               for (i = 0; i < area->nr_pages; i += 1U << page_order) {
+               for (i = 0; i < area->nr_pages; i += step) {
                        struct page *page = area->pages[i];
 
                        BUG_ON(!page);
+                       mod_memcg_page_state(page, MEMCG_VMALLOC, -step);
                        __free_pages(page, page_order);
                        cond_resched();
                }
@@ -2955,6 +2957,13 @@ 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);
+       if (gfp_mask & __GFP_ACCOUNT) {
+               int i, step = 1U << page_order;
+
+               for (i = 0; i < area->nr_pages; i += step)
+                       mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC,
+                                            step);
+       }
 
        /*
         * If not enough pages were obtained to accomplish an