[PATCH] mm: memcontrol: dump memory.stat during cgroup OOM
From: Johannes Weiner
Date: Tue Jun 04 2019 - 17:09:13 EST
The current cgroup OOM memory info dump doesn't include all the memory
we are tracking, nor does it give insight into what the VM tried to do
leading up to the OOM. All that useful info is in memory.stat.
Furthermore, the recursive printing for every child cgroup can
generate absurd amounts of data on the console for larger cgroup
trees, and it's not like we provide a per-cgroup breakdown during
global OOM kills.
When an OOM kill is triggered, print one set of recursive memory.stat
items at the level whose limit triggered the OOM condition.
Example output:
stress invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0
CPU: 2 PID: 210 Comm: stress Not tainted 5.2.0-rc2-mm1-00247-g47d49835983c #135
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-20181126_142135-anatol 04/01/2014
Call Trace:
dump_stack+0x46/0x60
dump_header+0x4c/0x2d0
oom_kill_process.cold.10+0xb/0x10
out_of_memory+0x200/0x270
? try_to_free_mem_cgroup_pages+0xdf/0x130
mem_cgroup_out_of_memory+0xb7/0xc0
try_charge+0x680/0x6f0
mem_cgroup_try_charge+0xb5/0x160
__add_to_page_cache_locked+0xc6/0x300
? list_lru_destroy+0x80/0x80
add_to_page_cache_lru+0x45/0xc0
pagecache_get_page+0x11b/0x290
filemap_fault+0x458/0x6d0
ext4_filemap_fault+0x27/0x36
__do_fault+0x2f/0xb0
__handle_mm_fault+0x9c5/0x1140
? apic_timer_interrupt+0xa/0x20
handle_mm_fault+0xc5/0x180
__do_page_fault+0x1ab/0x440
? page_fault+0x8/0x30
page_fault+0x1e/0x30
RIP: 0033:0x55c32167fc10
Code: Bad RIP value.
RSP: 002b:00007fff1d031c50 EFLAGS: 00010206
RAX: 000000000dc00000 RBX: 00007fd2db000010 RCX: 00007fd2db000010
RDX: 0000000000000000 RSI: 0000000010001000 RDI: 0000000000000000
RBP: 000055c321680a54 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000002 R14: 0000000000001000 R15: 0000000010000000
memory: usage 1024kB, limit 1024kB, failcnt 75131
swap: usage 0kB, limit 9007199254740988kB, failcnt 0
Memory cgroup stats for /foo:
anon 0
file 0
kernel_stack 36864
slab 274432
sock 0
shmem 0
file_mapped 0
file_dirty 0
file_writeback 0
anon_thp 0
inactive_anon 126976
active_anon 0
inactive_file 0
active_file 0
unevictable 0
slab_reclaimable 0
slab_unreclaimable 274432
pgfault 59466
pgmajfault 1617
workingset_refault 2145
workingset_activate 0
workingset_nodereclaim 0
pgrefill 98952
pgscan 200060
pgsteal 59340
pgactivate 40095
pgdeactivate 96787
pglazyfree 0
pglazyfreed 0
thp_fault_alloc 0
thp_collapse_alloc 0
Tasks state (memory values in pages):
[ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name
[ 200] 0 200 1121 884 53248 29 0 bash
[ 209] 0 209 905 246 45056 19 0 stress
[ 210] 0 210 66442 56 499712 56349 0 stress
oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),oom_memcg=/foo,task_memcg=/foo,task=stress,pid=210,uid=0
Memory cgroup out of memory: Killed process 210 (stress) total-vm:265768kB, anon-rss:0kB, file-rss:224kB, shmem-rss:0kB
oom_reaper: reaped process 210 (stress), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
mm/memcontrol.c | 289 ++++++++++++++++++++++++++----------------------
1 file changed, 157 insertions(+), 132 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6de8ca735ee2..0907a96ceddf 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -66,6 +66,7 @@
#include <linux/lockdep.h>
#include <linux/file.h>
#include <linux/tracehook.h>
+#include <linux/seq_buf.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
@@ -1365,27 +1366,114 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
return false;
}
-static const unsigned int memcg1_stats[] = {
- MEMCG_CACHE,
- MEMCG_RSS,
- MEMCG_RSS_HUGE,
- NR_SHMEM,
- NR_FILE_MAPPED,
- NR_FILE_DIRTY,
- NR_WRITEBACK,
- MEMCG_SWAP,
-};
+static char *memory_stat_format(struct mem_cgroup *memcg)
+{
+ struct seq_buf s;
+ int i;
-static const char *const memcg1_stat_names[] = {
- "cache",
- "rss",
- "rss_huge",
- "shmem",
- "mapped_file",
- "dirty",
- "writeback",
- "swap",
-};
+ seq_buf_init(&s, kvmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE);
+ if (!s.buffer)
+ return NULL;
+
+ /*
+ * Provide statistics on the state of the memory subsystem as
+ * well as cumulative event counters that show past behavior.
+ *
+ * This list is ordered following a combination of these gradients:
+ * 1) generic big picture -> specifics and details
+ * 2) reflecting userspace activity -> reflecting kernel heuristics
+ *
+ * Current memory state:
+ */
+
+ seq_buf_printf(&s, "anon %llu\n",
+ (u64)memcg_page_state(memcg, MEMCG_RSS) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "file %llu\n",
+ (u64)memcg_page_state(memcg, MEMCG_CACHE) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "kernel_stack %llu\n",
+ (u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) *
+ 1024);
+ seq_buf_printf(&s, "slab %llu\n",
+ (u64)(memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) +
+ memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE)) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "sock %llu\n",
+ (u64)memcg_page_state(memcg, MEMCG_SOCK) *
+ PAGE_SIZE);
+
+ seq_buf_printf(&s, "shmem %llu\n",
+ (u64)memcg_page_state(memcg, NR_SHMEM) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "file_mapped %llu\n",
+ (u64)memcg_page_state(memcg, NR_FILE_MAPPED) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "file_dirty %llu\n",
+ (u64)memcg_page_state(memcg, NR_FILE_DIRTY) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "file_writeback %llu\n",
+ (u64)memcg_page_state(memcg, NR_WRITEBACK) *
+ PAGE_SIZE);
+
+ /*
+ * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
+ * with the NR_ANON_THP vm counter, but right now it's a pain in the
+ * arse because it requires migrating the work out of rmap to a place
+ * where the page->mem_cgroup is set up and stable.
+ */
+ seq_buf_printf(&s, "anon_thp %llu\n",
+ (u64)memcg_page_state(memcg, MEMCG_RSS_HUGE) *
+ PAGE_SIZE);
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ seq_buf_printf(&s, "%s %llu\n", mem_cgroup_lru_names[i],
+ (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
+ PAGE_SIZE);
+
+ seq_buf_printf(&s, "slab_reclaimable %llu\n",
+ (u64)memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) *
+ PAGE_SIZE);
+ seq_buf_printf(&s, "slab_unreclaimable %llu\n",
+ (u64)memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE) *
+ PAGE_SIZE);
+
+ /* Accumulated memory events */
+
+ seq_buf_printf(&s, "pgfault %lu\n", memcg_events(memcg, PGFAULT));
+ seq_buf_printf(&s, "pgmajfault %lu\n", memcg_events(memcg, PGMAJFAULT));
+
+ seq_buf_printf(&s, "workingset_refault %lu\n",
+ memcg_page_state(memcg, WORKINGSET_REFAULT));
+ seq_buf_printf(&s, "workingset_activate %lu\n",
+ memcg_page_state(memcg, WORKINGSET_ACTIVATE));
+ seq_buf_printf(&s, "workingset_nodereclaim %lu\n",
+ memcg_page_state(memcg, WORKINGSET_NODERECLAIM));
+
+ seq_buf_printf(&s, "pgrefill %lu\n", memcg_events(memcg, PGREFILL));
+ seq_buf_printf(&s, "pgscan %lu\n",
+ memcg_events(memcg, PGSCAN_KSWAPD) +
+ memcg_events(memcg, PGSCAN_DIRECT));
+ seq_buf_printf(&s, "pgsteal %lu\n",
+ memcg_events(memcg, PGSTEAL_KSWAPD) +
+ memcg_events(memcg, PGSTEAL_DIRECT));
+ seq_buf_printf(&s, "pgactivate %lu\n", memcg_events(memcg, PGACTIVATE));
+ seq_buf_printf(&s, "pgdeactivate %lu\n", memcg_events(memcg, PGDEACTIVATE));
+ seq_buf_printf(&s, "pglazyfree %lu\n", memcg_events(memcg, PGLAZYFREE));
+ seq_buf_printf(&s, "pglazyfreed %lu\n", memcg_events(memcg, PGLAZYFREED));
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ seq_buf_printf(&s, "thp_fault_alloc %lu\n",
+ memcg_events(memcg, THP_FAULT_ALLOC));
+ seq_buf_printf(&s, "thp_collapse_alloc %lu\n",
+ memcg_events(memcg, THP_COLLAPSE_ALLOC));
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+ /* The above should easily fit into one page */
+ WARN_ON_ONCE(seq_buf_has_overflowed(&s));
+
+ return s.buffer;
+}
#define K(x) ((x) << (PAGE_SHIFT-10))
/**
@@ -1420,39 +1508,32 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *
*/
void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
{
- struct mem_cgroup *iter;
- unsigned int i;
+ char *buf;
pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
K((u64)page_counter_read(&memcg->memory)),
K((u64)memcg->memory.max), memcg->memory.failcnt);
- pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
- K((u64)page_counter_read(&memcg->memsw)),
- K((u64)memcg->memsw.max), memcg->memsw.failcnt);
- pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
- K((u64)page_counter_read(&memcg->kmem)),
- K((u64)memcg->kmem.max), memcg->kmem.failcnt);
-
- for_each_mem_cgroup_tree(iter, memcg) {
- pr_info("Memory cgroup stats for ");
- pr_cont_cgroup_path(iter->css.cgroup);
- pr_cont(":");
-
- for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
- if (memcg1_stats[i] == MEMCG_SWAP && !do_swap_account)
- continue;
- pr_cont(" %s:%luKB", memcg1_stat_names[i],
- K(memcg_page_state_local(iter,
- memcg1_stats[i])));
- }
-
- for (i = 0; i < NR_LRU_LISTS; i++)
- pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
- K(memcg_page_state_local(iter,
- NR_LRU_BASE + i)));
-
- pr_cont("\n");
+ if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->swap)),
+ K((u64)memcg->swap.max), memcg->swap.failcnt);
+ else {
+ pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->memsw)),
+ K((u64)memcg->memsw.max), memcg->memsw.failcnt);
+ pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
+ K((u64)page_counter_read(&memcg->kmem)),
+ K((u64)memcg->kmem.max), memcg->kmem.failcnt);
}
+
+ pr_info("Memory cgroup stats for ");
+ pr_cont_cgroup_path(memcg->css.cgroup);
+ pr_cont(":");
+ buf = memory_stat_format(memcg);
+ if (!buf)
+ return;
+ pr_info("%s", buf);
+ kvfree(buf);
}
/*
@@ -3484,6 +3565,28 @@ static int memcg_numa_stat_show(struct seq_file *m, void *v)
}
#endif /* CONFIG_NUMA */
+static const unsigned int memcg1_stats[] = {
+ MEMCG_CACHE,
+ MEMCG_RSS,
+ MEMCG_RSS_HUGE,
+ NR_SHMEM,
+ NR_FILE_MAPPED,
+ NR_FILE_DIRTY,
+ NR_WRITEBACK,
+ MEMCG_SWAP,
+};
+
+static const char *const memcg1_stat_names[] = {
+ "cache",
+ "rss",
+ "rss_huge",
+ "shmem",
+ "mapped_file",
+ "dirty",
+ "writeback",
+ "swap",
+};
+
/* Universal VM events cgroup1 shows, original sort order */
static const unsigned int memcg1_events[] = {
PGPGIN,
@@ -5666,91 +5769,13 @@ static int memory_events_local_show(struct seq_file *m, void *v)
static int memory_stat_show(struct seq_file *m, void *v)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
- int i;
-
- /*
- * Provide statistics on the state of the memory subsystem as
- * well as cumulative event counters that show past behavior.
- *
- * This list is ordered following a combination of these gradients:
- * 1) generic big picture -> specifics and details
- * 2) reflecting userspace activity -> reflecting kernel heuristics
- *
- * Current memory state:
- */
-
- seq_printf(m, "anon %llu\n",
- (u64)memcg_page_state(memcg, MEMCG_RSS) * PAGE_SIZE);
- seq_printf(m, "file %llu\n",
- (u64)memcg_page_state(memcg, MEMCG_CACHE) * PAGE_SIZE);
- seq_printf(m, "kernel_stack %llu\n",
- (u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) * 1024);
- seq_printf(m, "slab %llu\n",
- (u64)(memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) +
- memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE)) *
- PAGE_SIZE);
- seq_printf(m, "sock %llu\n",
- (u64)memcg_page_state(memcg, MEMCG_SOCK) * PAGE_SIZE);
-
- seq_printf(m, "shmem %llu\n",
- (u64)memcg_page_state(memcg, NR_SHMEM) * PAGE_SIZE);
- seq_printf(m, "file_mapped %llu\n",
- (u64)memcg_page_state(memcg, NR_FILE_MAPPED) * PAGE_SIZE);
- seq_printf(m, "file_dirty %llu\n",
- (u64)memcg_page_state(memcg, NR_FILE_DIRTY) * PAGE_SIZE);
- seq_printf(m, "file_writeback %llu\n",
- (u64)memcg_page_state(memcg, NR_WRITEBACK) * PAGE_SIZE);
-
- /*
- * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
- * with the NR_ANON_THP vm counter, but right now it's a pain in the
- * arse because it requires migrating the work out of rmap to a place
- * where the page->mem_cgroup is set up and stable.
- */
- seq_printf(m, "anon_thp %llu\n",
- (u64)memcg_page_state(memcg, MEMCG_RSS_HUGE) * PAGE_SIZE);
-
- for (i = 0; i < NR_LRU_LISTS; i++)
- seq_printf(m, "%s %llu\n", mem_cgroup_lru_names[i],
- (u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
- PAGE_SIZE);
-
- seq_printf(m, "slab_reclaimable %llu\n",
- (u64)memcg_page_state(memcg, NR_SLAB_RECLAIMABLE) *
- PAGE_SIZE);
- seq_printf(m, "slab_unreclaimable %llu\n",
- (u64)memcg_page_state(memcg, NR_SLAB_UNRECLAIMABLE) *
- PAGE_SIZE);
-
- /* Accumulated memory events */
-
- seq_printf(m, "pgfault %lu\n", memcg_events(memcg, PGFAULT));
- seq_printf(m, "pgmajfault %lu\n", memcg_events(memcg, PGMAJFAULT));
-
- seq_printf(m, "workingset_refault %lu\n",
- memcg_page_state(memcg, WORKINGSET_REFAULT));
- seq_printf(m, "workingset_activate %lu\n",
- memcg_page_state(memcg, WORKINGSET_ACTIVATE));
- seq_printf(m, "workingset_nodereclaim %lu\n",
- memcg_page_state(memcg, WORKINGSET_NODERECLAIM));
-
- seq_printf(m, "pgrefill %lu\n", memcg_events(memcg, PGREFILL));
- seq_printf(m, "pgscan %lu\n", memcg_events(memcg, PGSCAN_KSWAPD) +
- memcg_events(memcg, PGSCAN_DIRECT));
- seq_printf(m, "pgsteal %lu\n", memcg_events(memcg, PGSTEAL_KSWAPD) +
- memcg_events(memcg, PGSTEAL_DIRECT));
- seq_printf(m, "pgactivate %lu\n", memcg_events(memcg, PGACTIVATE));
- seq_printf(m, "pgdeactivate %lu\n", memcg_events(memcg, PGDEACTIVATE));
- seq_printf(m, "pglazyfree %lu\n", memcg_events(memcg, PGLAZYFREE));
- seq_printf(m, "pglazyfreed %lu\n", memcg_events(memcg, PGLAZYFREED));
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- seq_printf(m, "thp_fault_alloc %lu\n",
- memcg_events(memcg, THP_FAULT_ALLOC));
- seq_printf(m, "thp_collapse_alloc %lu\n",
- memcg_events(memcg, THP_COLLAPSE_ALLOC));
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+ char *buf;
+ buf = memory_stat_format(memcg);
+ if (!buf)
+ return -ENOMEM;
+ seq_puts(m, buf);
+ kvfree(buf);
return 0;
}
--
2.21.0