OOM on h2load

[krizhanovsky]

Scope

Tempesta FW on the current master as the date of the issue as well as on #1643 causes OOM on h2load -t 2 -c 1000 -D 60 https://ubuntu/ in a VM with 4GB RAM:

[38759.502337] Mem-Info:
[38759.504398] active_anon:228 inactive_anon:3 isolated_anon:0
[38759.504398]  active_file:46 inactive_file:39 isolated_file:0
[38759.504398]  unevictable:0 dirty:0 writeback:0
[38759.504398]  slab_reclaimable:3508 slab_unreclaimable:30742
[38759.504398]  mapped:8 shmem:12 pagetables:597 bounce:0
[38759.504398]  free:10508 free_pcp:48 free_cma:0
[38759.518162] Node 0 active_anon:912kB inactive_anon:12kB active_file:184kB inactive_file:156kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:32kB dirty:0kB writeback:0kB shmem:48kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB kernel_stack:4288kB all_unreclaimable? no
[38759.526902] Node 0 DMA free:12828kB min:328kB low:408kB high:488kB reserved_highatomic:2048KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[38759.537401] lowmem_reserve[]: 0 2747 3180 3180
[38759.540160] Node 0 DMA32 free:25044kB min:58096kB low:72620kB high:87144kB reserved_highatomic:2048KB active_anon:380kB inactive_anon:0kB active_file:32kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129204kB managed:3022552kB mlocked:0kB pagetables:112kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
[38759.550732] lowmem_reserve[]: 0 0 433 433
[38759.553397] Node 0 Normal free:4160kB min:9156kB low:11444kB high:13732kB reserved_highatomic:2048KB active_anon:748kB inactive_anon:20kB active_file:336kB inactive_file:56kB unevictable:0kB writepending:0kB present:1048576kB managed:443472kB mlocked:0kB pagetables:2276kB bounce:0kB free_pcp:296kB local_pcp:116kB free_cma:0kB
[38759.565720] lowmem_reserve[]: 0 0 0 0
[38759.568729] Node 0 DMA: 3*4kB (UMH) 2*8kB (MH) 4*16kB (UH) 4*32kB (UMH) 3*64kB (UH) 3*128kB (UH) 1*256kB (H) 1*512kB (U) 1*1024kB (U) 1*2048kB (M) 2*4096kB (ME) = 12828kB
[38759.576102] Node 0 DMA32: 1070*4kB (UMEH) 426*8kB (UMEH) 256*16kB (UMEH) 126*32kB (UME) 60*64kB (UME) 14*128kB (ME) 5*256kB (UM) 5*512kB (UM) 0*1024kB 0*2048kB 0*4096kB = 25288kB
[38759.584269] Node 0 Normal: 526*4kB (UMEH) 144*8kB (UMEH) 43*16kB (UMEH) 11*32kB (MH) 2*64kB (M) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4424kB
[38759.592210] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[38759.596744] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[38759.601633] 138 total pagecache pages
[38759.605448] 41 pages in swap cache
[38759.608985] Swap cache stats: add 18804, delete 18763, find 896/1162
[38759.613206] Free swap  = 3953004kB
[38759.617215] Total swap = 4025340kB
[38759.621236] 1048443 pages RAM
[38759.625012] 0 pages HighMem/MovableOnly
[38759.628929] 177960 pages reserved
[38759.633132] 0 pages hwpoisoned
[38759.636752] Unreclaimable slab info:
[38759.640447] Name                      Used          Total
[38759.644620] tfw_h2_conn_cache       2119KB       2198KB
[38759.648399] tfw_srv_conn_cache         33KB         36KB
[38759.652124] tfw_srv_cache              0KB          3KB
[38759.655882] tfw_stream_cache        5711KB       8848KB
[38759.659692] ext4_system_zone           1KB         54KB
[38759.664088] ext4_io_end_vec            3KB          3KB
[38759.667827] ext4_bio_post_read_ctx          8KB         11KB
[38759.671870] jbd2_inode                37KB         82KB
[38759.675407] scsi_sense_cache           0KB          8KB
[38759.678875] fib6_nodes                 0KB          4KB
[38759.682956] ip6_dst_cache              2KB          7KB
[38759.686864] RAWv6                     11KB         11KB
[38759.691002] UDPv6                      2KB         14KB
[38759.694593] tw_sock_TCPv6              0KB          3KB
[38759.698083] TCPv6                  66007KB      66090KB
[38759.701573] sgpool-128                 8KB          8KB
[38759.704949] sgpool-64                  4KB          6KB
[38759.708055] sgpool-32                  2KB          7KB
[38759.711511] sgpool-16                  1KB          3KB
[38759.714490] sgpool-8                   0KB          3KB
[38759.717649] mqueue_inode_cache          1KB          7KB
[38759.720965] bio-2                      1KB          3KB
[38759.724244] fasync_cache               0KB          3KB
[38759.727056] UNIX                     153KB        315KB
[38759.729758] tcp_bind_bucket            5KB         16KB
[38759.732398] ip_fib_trie                0KB          3KB

Testing

Surprisingly http2_general/test_h2_specs.py runs h2load for 100 seconds, so it seems larger VMs are used....