Sorry for the delay; was AF(that)K for the weekend. > Ok, is there any chance you can capture more of sysrq+m, particularly the > bits that say how much free memory there is and many pages of each order > that is free? If you can't, it's ok. I ask because my kernel bug dowsing > rod is twitching in the direction of the recent free page accounting bug > Dave Hansen identified and fixed -- https://lkml.org/lkml/2012/11/21/504 Okay; as mentioned, I installed that patch and it didn't make any obvious difference to the symptoms. The hang IP is still either in __zone_watermark_ok or kswapd (address varies). > The free page counter and these free lists should be close together. If > there is a big gap then it's almost certainly the bug Dave identified. The full sysrq-M output (at least the 49 lines I could read without working scrollback) is here. I went over it twice (at least, all the varying numbers; I may have a typo in some of the fixed text), so I'm pretty sure it's right. DMA per-cpu: CPU 0: hi: 0, btch: 1 usd: 0 Normal per-cpu: CPU 0: hi: 186, btch: 31 usd: 181 HighMem per-cpu: CPU 0: hi: 186, btch: 31 usd: 172 active_anon:14759 inactive_anon:6504 isolated_anon:0 active_file:126610 inactive_file:283340 isolated_file:0 unevictable:0 dirty:289 writeback:0 unstable:0 free:39060 slab_reclaimable:44235 slab_unreclaimable:1079 mapped:4468 shmem:580 pagetables:301 bounce:0 free_cma:0 DMA free:9044kB min:784kB low:980kB high:1176kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:6868kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15804kB mlocked:0kB dirty:4kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 865 2016 2016 Normal free:107016kB min:44012kB low:55012kB high:66016kB active_anon:9096kB inactive_anon:9344kB active_file:296716kB inactive_file:257136kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:885944kB mlocked:0kB dirty:1152kB writeback:0kB mapped:4kB shmem:0kB slab_reclaimable:176940kB slab_unreclaimable:4316kB kernel_stack:1104kB pagetables:1204kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 9207 9207 HighMem free:40180kB min:512kB low:15148kB high:29784kB active_anon:49940kB inactive_anon:16672kB active_file:209724kB inactive_file:869356kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:1178552kB mlocked:0kB dirty:4kB writeback:0kB mapped:17868kB shmem:2320kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no lowmem_Reserve[]: 0 0 0 0 DMA: 1*4kB 2*8kB 2*16kB 1*32kB 2*64kB 1*128kB 2*256kB 2*512kB 1*1024kB 1*2048kB 1*4096kB = 9044kB Normal: 572*4kB 129*8kB 33*16kB 42*32kB 33*64kB 15*128kB 8*256kB 3*512kB 6*1024kB 3*2048kB 20*4096kB = 107016kB HighMem: 407*4kB 199*8kB 124*16kB 107*32kB 53*64kB 10*128kB 5*256kB 4*512kB 3*1024kB 2*2048kB 4*4096kB = 40180kB 410530 total pagecahce pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 4883724kB Total swap = 4883724kB 524268 pages RAM 296958 pages HighMem 5331 pages reserved 390516 pages shared FLUCTUATES: 390508, 468, 412, 492, 484, 428, 524, 452, 468, ... 366021 pages non-shared As mentioned, the "shared" number fluctuates, and the "Normal" free pages count also fluctuates a little bit, but less. (The 32kB free count is sometimes 43 or 41 rather than 42, bringing the total to 107048 or 106984.) I do see that the free space figures appear to agree. I couldn't find a number that appeared to change in sync with the "pages shared" figure. I could remove Dave Hansen's patch and test again, if that would help. Any other ideas? Thank you very much for the assistance! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>