Hi, Here's a revised patch to fix and optimize interrupt distribution. The major change since the last patch is that a tree representation of the CPU hierarchy is built from the per CPU cpu_data. Each iteration through the CPU tree picks the next optimal CPU. The following are example CPU distribution maps for various Niagara2/2+ machines. T5220 (64 cpus) { 0 8 16 24 32 40 48 56 4 12 20 28 36 44 52 60 1 9 17 25 33 41 49 57 5 13 21 29 37 45 53 61 2 10 18 26 34 42 50 58 6 14 22 30 38 46 54 62 3 11 19 27 35 43 51 59 7 15 23 31 39 47 55 63} T5440 (2 way, 96 cpus) { 0 8 16 24 32 40 72 80 88 96 104 112 4 12 20 28 36 44 76 84 92 100 108 116 1 9 17 25 33 41 73 81 89 97 105 113 5 13 21 29 37 45 77 85 93 101 109 117 2 10 18 26 34 42 74 82 90 98 106 114 6 14 22 30 38 46 78 86 94 102 110 118 3 11 19 27 35 43 75 83 91 99 107 115 7 15 23 31 39 47 79 87 95 103 111 119} LDOM (on a T5220) { 0 3 1 4 2 5 0 6} An assumption used when building the CPU tree is that cpu_data is sorted by node, core_id, and proc_id (in order of significance). This the case for the Niagara2 machines I have available. If this isn't true for all sparc64 machines, a copy of cpu_data would need to be sorted prior to building the CPU tree. Regards, Hong -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html