Hi, Is there a maximum table size for the device mapper? Or put in other words, what is the relation between table size and memory usage? It probably depends on the target, but is there an estimate for the linear and the crypt targets? And what's the performance impact of having big tables? I tried to set up a device with a lot (about 3000) crypt targets, and this was obviously way too much as the oom-killer kicked in. Please cc me on your reply as I am not subscribed. Thanks, Michael dmesg output: dmsetup invoked oom-killer: gfp_mask=0xd0, order=1, oomkilladj=0 [<c013cdbc>] out_of_memory+0x69/0x189 [<c013e24f>] __alloc_pages+0x203/0x28d [<c0140e8a>] wakeup_kswapd+0x2d/0x70 [<c0151dee>] cache_alloc_refill+0x27d/0x47f [<c0151b67>] kmem_cache_alloc+0x3d/0x47 [<c013c859>] mempool_create_node+0x96/0xb4 [<c013c687>] mempool_free_slab+0x0/0xb [<c013c671>] mempool_alloc_slab+0x0/0xb [<c013c88f>] mempool_create+0x18/0x1c [<c017119a>] bioset_create+0x65/0x8a [<c031d9f1>] crypt_ctr+0x3a2/0x5db [<c0318fd3>] dm_split_args+0x39/0xc8 [<c03197d3>] dm_table_add_target+0x149/0x270 [<c031adf4>] table_load+0xf0/0x1ab [<c031b887>] ctl_ioctl+0x212/0x257 [<c031ad04>] table_load+0x0/0x1ab [<c031b675>] ctl_ioctl+0x0/0x257 [<c031b675>] ctl_ioctl+0x0/0x257 [<c015dfcf>] do_ioctl+0x87/0x9f [<c015e21e>] vfs_ioctl+0x237/0x249 [<c015e263>] sys_ioctl+0x33/0x4c [<c01024ba>] sysenter_past_esp+0x5f/0x85 [<c0380000>] xs_sendpages+0x13/0x1c0 ======================= Mem-info: DMA per-cpu: CPU 0: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 CPU 1: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 Normal per-cpu: CPU 0: Hot: hi: 186, btch: 31 usd: 29 Cold: hi: 62, btch: 15 usd: 45 CPU 1: Hot: hi: 186, btch: 31 usd: 92 Cold: hi: 62, btch: 15 usd: 54 HighMem per-cpu: CPU 0: Hot: hi: 186, btch: 31 usd: 1 Cold: hi: 62, btch: 15 usd: 10 CPU 1: Hot: hi: 186, btch: 31 usd: 171 Cold: hi: 62, btch: 15 usd: 3 Active:3672 inactive:89 dirty:10 writeback:0 unstable:0 free:284215 slab:128693 mapped:770 pagetables:57 bounce:0 DMA free:3548kB min:68kB low:84kB high:100kB active:0kB inactive:0kB present:16256kB pages_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 873 1989 Normal free:3736kB min:3744kB low:4680kB high:5616kB active:28kB inactive:0kB present:894080kB pages_scanned:72 all_unreclaimable? yes lowmem_reserve[]: 0 0 8929 HighMem free:1129576kB min:512kB low:1708kB high:2904kB active:14660kB inactive:420kB present:1143000kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 DMA: 1*4kB 1*8kB 1*16kB 0*32kB 1*64kB 1*128kB 1*256kB 4*512kB 1*1024kB 0*2048kB 0*4096kB = 3548kB Normal: 31*4kB 0*8kB 1*16kB 1*32kB 1*64kB 1*128kB 1*256kB 0*512kB 1*1024kB 1*2048kB 0*4096kB = 3692kB HighMem: 0*4kB 1*8kB 404*16kB 284*32kB 215*64kB 178*128kB 137*256kB 104*512kB 70*1024kB 28*2048kB 210*4096kB = 1129608kB Swap cache: add 45, delete 1, find 0/1, race 0+0 Free swap = 5879584kB Total swap = 5879760kB Free swap: 5879584kB 517376 pages of RAM 288000 pages of HIGHMEM 5732 reserved pages 3896 pages shared 44 pages swap cached 10 pages dirty 0 pages writeback 770 pages mapped 128693 pages slab 57 pages pagetables Out of memory: kill process 19418 (iamap.sh) score 107 or a child Killed process 19423 (dmsetup) dmsetup: page allocation failure. order:0, mode:0xd0 [<c013e2c8>] __alloc_pages+0x27c/0x28d [<c013c859>] mempool_create_node+0x96/0xb4 [<c013c5bc>] mempool_free_pages+0x0/0x5 [<c013c5f6>] mempool_alloc_pages+0x0/0x31 [<c013c88f>] mempool_create+0x18/0x1c [<c031d4cb>] crypt_iv_benbi_ctr+0x0/0x52 [<c031d9c7>] crypt_ctr+0x378/0x5db [<c0318fd3>] dm_split_args+0x39/0xc8 [<c03197d3>] dm_table_add_target+0x149/0x270 [<c031adf4>] table_load+0xf0/0x1ab [<c031b887>] ctl_ioctl+0x212/0x257 [<c031ad04>] table_load+0x0/0x1ab [<c031b675>] ctl_ioctl+0x0/0x257 [<c031b675>] ctl_ioctl+0x0/0x257 [<c015dfcf>] do_ioctl+0x87/0x9f [<c015e21e>] vfs_ioctl+0x237/0x249 [<c015e263>] sys_ioctl+0x33/0x4c [<c01024ba>] sysenter_past_esp+0x5f/0x85 [<c0380000>] xs_sendpages+0x13/0x1c0 ======================= Mem-info: DMA per-cpu: CPU 0: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 CPU 1: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 Normal per-cpu: CPU 0: Hot: hi: 186, btch: 31 usd: 29 Cold: hi: 62, btch: 15 usd: 45 CPU 1: Hot: hi: 186, btch: 31 usd: 0 Cold: hi: 62, btch: 15 usd: 54 HighMem per-cpu: CPU 0: Hot: hi: 186, btch: 31 usd: 1 Cold: hi: 62, btch: 15 usd: 10 CPU 1: Hot: hi: 186, btch: 31 usd: 171 Cold: hi: 62, btch: 15 usd: 3 Active:3673 inactive:109 dirty:10 writeback:0 unstable:0 free:282421 slab:129796 mapped:770 pagetables:57 bounce:0 DMA free:12kB min:68kB low:84kB high:100kB active:0kB inactive:0kB present:16256kB pages_scanned:0 all_unreclaimable? yes lowmem_reserve[]: 0 873 1989 Normal free:96kB min:3744kB low:4680kB high:5616kB active:32kB inactive:16kB present:894080kB pages_scanned:954 all_unreclaimable? yes lowmem_reserve[]: 0 0 8929 HighMem free:1129576kB min:512kB low:1708kB high:2904kB active:14660kB inactive:420kB present:1143000kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 0kB Normal: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 0kB HighMem: 0*4kB 1*8kB 404*16kB 284*32kB 215*64kB 178*128kB 137*256kB 104*512kB 70*1024kB 28*2048kB 210*4096kB = 1129608kB Swap cache: add 45, delete 1, find 0/1, race 0+0 Free swap = 5879584kB Total swap = 5879760kB Free swap: 5879584kB 517376 pages of RAM 288000 pages of HIGHMEM 5732 reserved pages 3896 pages shared 44 pages swap cached 10 pages dirty 0 pages writeback 770 pages mapped 129796 pages slab 57 pages pagetables device-mapper: table: 253:1: crypt: Cannot allocate page mempool device-mapper: ioctl: error adding target to table -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
