Re: Possible mem cgroup bug in kernels between 4.18.0 and 5.3-rc1.
From: Tetsuo Handa
Date: Fri Aug 02 2019 - 22:37:20 EST
Well, while mem_cgroup_oom() is actually called, due to hitting
/*
* The OOM killer does not compensate for IO-less reclaim.
* pagefault_out_of_memory lost its gfp context so we have to
* make sure exclude 0 mask - all other users should have at least
* ___GFP_DIRECT_RECLAIM to get here.
*/
if (oc->gfp_mask && !(oc->gfp_mask & __GFP_FS))
return true;
path inside out_of_memory(), OOM_SUCCESS is returned and retrying without
making forward progress...
----------------------------------------
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2447,6 +2447,8 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
*/
oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask,
get_order(nr_pages * PAGE_SIZE));
+ printk("mem_cgroup_oom(%pGg)=%u\n", &gfp_mask, oom_status);
+ dump_stack();
switch (oom_status) {
case OOM_SUCCESS:
nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
----------------------------------------
----------------------------------------
[ 55.208578][ T2798] mem_cgroup_oom(GFP_NOFS)=0
[ 55.210424][ T2798] CPU: 3 PID: 2798 Comm: leaker Not tainted 5.3.0-rc2+ #637
[ 55.212985][ T2798] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
[ 55.217260][ T2798] Call Trace:
[ 55.218597][ T2798] dump_stack+0x67/0x95
[ 55.220200][ T2798] try_charge+0x4ca/0x6d0
[ 55.221843][ T2798] ? get_mem_cgroup_from_mm+0x1ff/0x2c0
[ 55.223855][ T2798] mem_cgroup_try_charge+0x88/0x2d0
[ 55.225723][ T2798] __add_to_page_cache_locked+0x27e/0x4c0
[ 55.227784][ T2798] ? scan_shadow_nodes+0x30/0x30
[ 55.229577][ T2798] add_to_page_cache_lru+0x72/0x180
[ 55.231467][ T2798] iomap_readpages_actor+0xeb/0x1e0
[ 55.233376][ T2798] ? iomap_migrate_page+0x120/0x120
[ 55.235382][ T2798] iomap_apply+0xaf/0x150
[ 55.237049][ T2798] iomap_readpages+0x9f/0x160
[ 55.239061][ T2798] ? iomap_migrate_page+0x120/0x120
[ 55.241013][ T2798] xfs_vm_readpages+0x54/0x130 [xfs]
[ 55.242960][ T2798] read_pages+0x63/0x160
[ 55.244613][ T2798] __do_page_cache_readahead+0x1cd/0x200
[ 55.246699][ T2798] ondemand_readahead+0x201/0x4d0
[ 55.248562][ T2798] page_cache_async_readahead+0x16e/0x2e0
[ 55.250740][ T2798] ? page_cache_async_readahead+0xa5/0x2e0
[ 55.252881][ T2798] filemap_fault+0x3f3/0xc20
[ 55.254813][ T2798] ? xfs_ilock+0x1de/0x2c0 [xfs]
[ 55.256858][ T2798] ? __xfs_filemap_fault+0x7f/0x270 [xfs]
[ 55.259118][ T2798] ? down_read_nested+0x98/0x170
[ 55.261123][ T2798] ? xfs_ilock+0x1de/0x2c0 [xfs]
[ 55.263146][ T2798] __xfs_filemap_fault+0x92/0x270 [xfs]
[ 55.265210][ T2798] xfs_filemap_fault+0x27/0x30 [xfs]
[ 55.267164][ T2798] __do_fault+0x33/0xd0
[ 55.268784][ T2798] do_fault+0x3be/0x5c0
[ 55.270390][ T2798] __handle_mm_fault+0x462/0xc00
[ 55.272251][ T2798] handle_mm_fault+0x17c/0x380
[ 55.274055][ T2798] ? handle_mm_fault+0x46/0x380
[ 55.275877][ T2798] __do_page_fault+0x24a/0x4c0
[ 55.277676][ T2798] do_page_fault+0x27/0x1b0
[ 55.279399][ T2798] page_fault+0x34/0x40
[ 55.281053][ T2798] RIP: 0033:0x4009f0
[ 55.282564][ T2798] Code: 03 00 00 00 e8 71 fd ff ff 48 83 f8 ff 49 89 c6 74 74 48 89 c6 bf c0 0c 40 00 31 c0 e8 69 fd ff ff 45 85 ff 7e 21 31 c9 66 90 <41> 0f be 14 0e 01 d3 f7 c1 ff 0f 00 00 75 05 41 c6 04 0e 2a 48 83
[ 55.289631][ T2798] RSP: 002b:00007fff1804ec00 EFLAGS: 00010206
[ 55.291835][ T2798] RAX: 000000000000001b RBX: 0000000000000000 RCX: 0000000001a1a000
[ 55.294745][ T2798] RDX: 0000000000000000 RSI: 000000007fffffe5 RDI: 0000000000000000
[ 55.297500][ T2798] RBP: 000000000000000c R08: 0000000000000000 R09: 00007f4e7392320d
[ 55.300225][ T2798] R10: 0000000000000002 R11: 0000000000000246 R12: 00000000000186a0
[ 55.303047][ T2798] R13: 0000000000000003 R14: 00007f4e530d6000 R15: 0000000002800000
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