On Mon, 18 Jul 2011 23:35:56 +0200 Peter Zijlstra <a.p.zijls...@chello.nl> wrote:
> Anton, could you test the below two patches on that machine? > > It should make things boot again, while I don't have a machine nearly > big enough to trigger any of this, I tested the new code paths by > setting FORCE_SD_OVERLAP in /debug/sched_features. Although any review > of the error paths would be much appreciated. I get an oops in slub code: NIP [c000000000197d30] .deactivate_slab+0x1b0/0x200 LR [c000000000199d94] .__slab_alloc+0xb4/0x5a0 [c000000000199d94] .__slab_alloc+0xb4/0x5a0 [c00000000019ac98] .kmem_cache_alloc_node_trace+0xa8/0x260 [c00000000007eb70] .build_sched_domains+0xa60/0xb90 [c000000000a16a98] .sched_init_smp+0xa8/0x228 [c000000000a00274] .kernel_init+0x10c/0x1fc [c00000000002324c] .kernel_thread+0x54/0x70 I'm guessing it's a result of some nodes not having any local memory. but a bit surprised I'm not seeing it elsewhere. Investigating. > Also, could you send me the node_distance table for that machine? I'm > curious what the interconnects look like on that thing. Our node distances are a bit arbitrary (I make them up based on information given to us in the device tree). In terms of memory we have a maximum of three levels. To give some gross estimates, on chip memory might be 30GB/sec, on node memory 10-15GB/sec and off node memory 5GB/sec. The only thing we tweak with node distances is to make sure we go into node reclaim before going off node: /* * Before going off node we want the VM to try and reclaim from the local * node. It does this if the remote distance is larger than RECLAIM_DISTANCE. * With the default REMOTE_DISTANCE of 20 and the default RECLAIM_DISTANCE of * 20, we never reclaim and go off node straight away. * * To fix this we choose a smaller value of RECLAIM_DISTANCE. */ #define RECLAIM_DISTANCE 10 Anton node distances: node 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0: 10 20 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 1: 20 10 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 2: 20 20 10 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 3: 20 20 20 10 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 4: 40 40 40 40 10 20 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 5: 40 40 40 40 20 10 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 6: 40 40 40 40 20 20 10 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 7: 40 40 40 40 20 20 20 10 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 8: 40 40 40 40 40 40 40 40 10 20 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 9: 40 40 40 40 40 40 40 40 20 10 20 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 10: 40 40 40 40 40 40 40 40 20 20 10 20 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 11: 40 40 40 40 40 40 40 40 20 20 20 10 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 12: 40 40 40 40 40 40 40 40 40 40 40 40 10 20 20 20 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 13: 40 40 40 40 40 40 40 40 40 40 40 40 20 10 20 20 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 14: 40 40 40 40 40 40 40 40 40 40 40 40 20 20 10 20 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 15: 40 40 40 40 40 40 40 40 40 40 40 40 20 20 20 10 40 40 40 40 40 40 40 40 40 40 40 40 0 0 0 0 16: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 10 20 20 20 40 40 40 40 40 40 40 40 0 0 0 0 17: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 10 20 20 40 40 40 40 40 40 40 40 0 0 0 0 18: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 10 20 40 40 40 40 40 40 40 40 0 0 0 0 19: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 20 10 40 40 40 40 40 40 40 40 0 0 0 0 20: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 10 20 20 20 40 40 40 40 0 0 0 0 21: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 10 20 20 40 40 40 40 0 0 0 0 22: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 10 20 40 40 40 40 0 0 0 0 23: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 20 10 40 40 40 40 0 0 0 0 24: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 25: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 26: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 27: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 28: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 10 20 20 20 0 0 0 0 29: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 10 20 20 0 0 0 0 30: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 10 20 0 0 0 0 31: 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 40 20 20 20 10 0 0 0 0 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev