MaxMemInCellQueues minimum of 256MB is still too large for low-RAM relays (LEDE and OpenWRT routers)
The minimum value for torrc configuration MaxMemInCellQueues of 256MB is still too large for memory constrained relays. I've been running a tor relay on my OpenWRT router for a few years reliably. I recently upgraded the router to use tor 0.2.9.12 where MaxMemInCellQueues is minimally defaulted to 256MB, even if the router only has 128 MB. Naturally, Linux oom-killer kills it after a few hours. I have a lot of bandwidth but I can't share it now...
This is related to ticket legacy/trac#9686 (moved)
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.070987] Mem-Info:
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] active_anon:18341 inactive_anon:51 isolated_anon:0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] active_file:35 inactive_file:73 isolated_file:0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] unevictable:0 dirty:0 writeback:0 unstable:0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] slab_reclaimable:728 slab_unreclaimable:2804
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] mapped:41 shmem:1120 pagetables:102 bounce:0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.073403] free:4723 free_pcp:40 free_cma:0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.106437] Normal free:18892kB min:16384kB low:20480kB high:24576kB active_anon:73364kB inactive_anon:204kB active_file:
140kB inactive_file:292kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:131072kB managed:125640kB mlocked:0kB dirty:0kB writeback:0kB mapped:164kB shmem
:4480kB slab_reclaimable:2912kB slab_unreclaimable:11216kB kernel_stack:544kB pagetables:408kB unstable:0kB bounce:0kB free_pcp:160kB local_pcp:160kB free_cma:0kB write
back_tmWed Nov 15 11:24:32 2017 kern.warn kernel: [221491.151989] lowmem_reserve[]: 0 0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.155468] Normal: 763*4kB (UMEH) 446*8kB (UMEH) 255*16kB (UMEH) 44*32kB (UME) 20*64kB (UMEH) 3*128kB (UME) 2*256kB (UH)
1*512kB (U) 4*1024kB (UMH) 0*2048kB 0*4096kB = 18892kB
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.171705] 1228 total pagecache pages
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.175610] 0 pages in swap cache
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.179077] Swap cache stats: add 0, delete 0, find 0/0
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.184476] Free swap = 0kB
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.187482] Total swap = 0kB
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.190505] 32768 pages RAM
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.193422] 0 pages HighMem/MovableOnly
Wed Nov 15 11:24:32 2017 kern.warn kernel: [221491.197412] 1358 pages reserved
Wed Nov 15 11:24:32 2017 kern.info kernel: [221491.200683] [ pid ] uid tgid total_vm rss nr_ptes nr_pmds swapents oom_score_adj name
...
Wed Nov 15 11:24:32 2017 kern.info kernel: [221491.370877] [28850] 52 28850 21220 15276 25 0 0 0 tor
Wed Nov 15 11:24:32 2017 kern.info kernel: [221491.379539] [ 9935] 0 9935 296 9 3 0 0 0 sleep
Wed Nov 15 11:24:32 2017 kern.err kernel: [221491.388387] Out of memory: Kill process 28850 (tor) score 487 or sacrifice child
Wed Nov 15 11:24:32 2017 kern.err kernel: [221491.396016] Killed process 28850 (tor) total-vm:84880kB, anon-rss:61096kB, file-rss:8kBTrac:
Username: pmetras