On 2017/5/24 9:40, Xishi Qiu wrote: > Hi, I find we use rcu access task_struct in mm_match_cgroup(), but not use > rcu free in free_task_struct(), is it right? > > Here is the backtrace. > > PID: 2133 TASK: ffff881fe3353300 CPU: 2 COMMAND: "CPU 15/KVM" > #0 [ffff881fe276b528] machine_kexec at ffffffff8105280b > #1 [ffff881fe276b588] crash_kexec at ffffffff810f5072 > #2 [ffff881fe276b658] panic at ffffffff8163e23b > #3 [ffff881fe276b6d8] oops_end at ffffffff8164d61b > #4 [ffff881fe276b700] die at ffffffff8101872b > #5 [ffff881fe276b730] do_general_protection at ffffffff8164cefe > #6 [ffff881fe276b760] general_protection at ffffffff8164c7a8 > [exception RIP: mem_cgroup_from_task+22] > RIP: ffffffff811db536 RSP: ffff881fe276b810 RFLAGS: 00010286 > RAX: 6b6b6b6b6b6b6b6b RBX: ffffea007f988880 RCX: 0000000000020000 > RDX: 00000007fa607d67 RSI: 00000007fa607d67 RDI: ffff880fe36d72c0 > RBP: ffff881fe276b880 R8: 00000007fa607600 R9: a801fd67b3000000 > R10: 57fdec98cc59ecc0 R11: ffff880fe2e8dbd0 R12: ffffc9001cb74000 > R13: ffff881fdb8cfda0 R14: ffff881fe2581570 R15: 00000007fa607d67 > ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 > #7 [ffff881fe276b810] page_referenced at ffffffff811a6b8a > #8 [ffff881fe276b888] shrink_page_list at ffffffff81180994 > #9 [ffff881fe276b9c0] shrink_inactive_list at ffffffff8118166a > #10 [ffff881fe276ba88] shrink_lruvec at ffffffff81182135 > #11 [ffff881fe276bb88] shrink_zone at ffffffff81182596 > #12 [ffff881fe276bbe0] do_try_to_free_pages at ffffffff81182a90 > #13 [ffff881fe276bc58] try_to_free_mem_cgroup_pages at ffffffff81182fea > #14 [ffff881fe276bcf0] mem_cgroup_reclaim at ffffffff811dd8de > #15 [ffff881fe276bd30] __mem_cgroup_try_charge at ffffffff811ddd9c > #16 [ffff881fe276bdf0] __mem_cgroup_try_charge_swapin at ffffffff811df62b > #17 [ffff881fe276be28] mem_cgroup_try_charge_swapin at ffffffff811e0537 > #18 [ffff881fe276be38] handle_mm_fault at ffffffff8119abdd > #19 [ffff881fe276bec8] __do_page_fault at ffffffff816502d6 > #20 [ffff881fe276bf28] do_page_fault at ffffffff81650603 > #21 [ffff881fe276bf50] page_fault at ffffffff8164c808 > RIP: 00007fdaba456500 RSP: 00007fdaaba6c978 RFLAGS: 00010246 > RAX: ffffffffffffffff RBX: 0000000000000000 RCX: fffffffffffffbd0 > RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000002c > RBP: 00007fdaaba6c9f0 R8: 0000000000840c70 R9: 00000000000000be > R10: 000000007fffffff R11: 0000000000000246 R12: 0000000003622010 > R13: 000000000000ae80 R14: 00000000008274e0 R15: 0000000003622010 > ORIG_RAX: ffffffffffffffff CS: 0033 SS: 002b > > > . > -- 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>
