On Wed, May 31, 2017 at 08:42:27AM +0200, Michal Hocko wrote: > From: Michal Hocko <mhocko@xxxxxxxx> > > We have seen an early OOM killer invocation on ppc64 systems with > crashkernel=4096M > kthreadd invoked oom-killer: gfp_mask=0x16040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK), nodemask=7, order=0, oom_score_adj=0 > kthreadd cpuset=/ mems_allowed=7 > CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.4.68-1.gd7fe927-default #1 > Call Trace: > [c0000000072fb7c0] [c00000000080830c] dump_stack+0xb0/0xf0 (unreliable) > [c0000000072fb800] [c0000000008032d4] dump_header+0xb0/0x258 > [c0000000072fb8e0] [c00000000023dfc0] out_of_memory+0x5f0/0x640 > [c0000000072fb990] [c00000000024459c] __alloc_pages_nodemask+0xa8c/0xc80 > [c0000000072fbb10] [c0000000002b2504] kmem_getpages+0x84/0x1a0 > [c0000000072fbb50] [c0000000002b5174] fallback_alloc+0x2a4/0x320 > [c0000000072fbbc0] [c0000000002b4240] kmem_cache_alloc_node+0xc0/0x2e0 > [c0000000072fbc30] [c0000000000b9a80] copy_process.isra.25+0x260/0x1b30 > [c0000000072fbd10] [c0000000000bb514] _do_fork+0x94/0x470 > [c0000000072fbd80] [c0000000000bb978] kernel_thread+0x48/0x60 > [c0000000072fbda0] [c0000000000e9df4] kthreadd+0x264/0x330 > [c0000000072fbe30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4 > Mem-Info: > active_anon:0 inactive_anon:0 isolated_anon:0 > active_file:0 inactive_file:0 isolated_file:0 > unevictable:0 dirty:0 writeback:0 unstable:0 > slab_reclaimable:5 slab_unreclaimable:73 > mapped:0 shmem:0 pagetables:0 bounce:0 > free:0 free_pcp:0 free_cma:0 > Node 7 DMA free:0kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:52428800kB managed:110016kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:320kB slab_unreclaimable:4672kB kernel_stack:1152kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes > lowmem_reserve[]: 0 0 0 0 > Node 7 DMA: 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 0kB > 0 total pagecache pages > 0 pages in swap cache > Swap cache stats: add 0, delete 0, find 0/0 > Free swap = 0kB > Total swap = 0kB > 819200 pages RAM > 0 pages HighMem/MovableOnly > 817481 pages reserved > 0 pages cma reserved > 0 pages hwpoisoned > > the reason is that the managed memory is too low (only 110MB) while the > rest of the the 50GB is still waiting for the deferred intialization to > be done. update_defer_init estimates the initial memoty to initialize to > 2GB at least but it doesn't consider any memory allocated in that range. > In this particular case we've had > Reserving 4096MB of memory at 128MB for crashkernel (System RAM: 51200MB) > so the low 2GB is mostly depleted. > > Fix this by considering memblock allocations in the initial static > initialization estimation. Move the max_initialise to reset_deferred_meminit > and implement a simple memblock_reserved_memory helper which iterates all > reserved blocks and sums the size of all that start below the given address. > The cumulative size is than added on top of the initial estimation. This > is still not ideal because reset_deferred_meminit doesn't consider holes > and so reservation might be above the initial estimation whihch we > ignore but let's make the logic simpler until we really need to handle > more complicated cases. > > Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set") > Cc: stable # 4.2+ > Tested-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> -- Mel Gorman SUSE Labs -- 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>