lkml.org 
[lkml]   [2008]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    Subject[BUG][PPC64] BUG in 2.6.26.5-rt9 causing Hang
    Hi Gregory,
    We see the following BUG followed by a hang on the latest kernel 2.6.26.5-rt9 on a Power6 blade (PPC64)
    It is easily recreated by running the async_handler or sbrk_mutex (realtime tests from ltp) tests.

    login: cpu 0x2: Vector: 700 (Program Check) at [c0000000e8e875d0]
    pc: c00000000005110c: .pick_next_pushable_task+0x54/0x9c
    lr: c000000000059f50: .push_rt_task+0x44/0x2b4
    sp: c0000000e8e87850
    msr: 8000000000021032
    current = 0xc0000000ea5bb2e0
    paca = 0xc000000000608700
    pid = 2811, comm = async_handler
    kernel BUG at kernel/sched_rt.c:1041! <---------------------
    enter ? for help
    [link register ] c000000000059f50 .push_rt_task+0x44/0x2b4
    [c0000000e8e87850] c0000000e8e878f0 (unreliable)
    [c0000000e8e87900] c00000000005a1dc .push_rt_tasks+0x1c/0x38
    [c0000000e8e87980] c00000000005a21c .post_schedule_rt+0x24/0x44
    [c0000000e8e87a10] c000000000057cbc .finish_task_switch+0xd0/0x180
    [c0000000e8e87ab0] c0000000003b6e88 .__schedule+0x6e0/0x798
    [c0000000e8e87b90] c0000000003b7148 .schedule+0xec/0x11c
    [c0000000e8e87c10] c0000000003b7a40 .do_nanosleep+0x6c/0xcc
    [c0000000e8e87c90] c000000000080738 .hrtimer_nanosleep+0x7c/0x100
    [c0000000e8e87d90] c000000000080830 .sys_nanosleep+0x74/0x94
    [c0000000e8e87e30] c0000000000086ac syscall_exit+0x0/0x40
    --- Exception: c00 (System Call) at 0000008026449844
    SP (400014185f0) is in userspace


    This is generated by the BUG_ON lines in the pick_next_pushable function
    introduced by the sched-only-push-once-per-queue.patch .

    The -rt kernel prior to this patch didnot give such BUGes.

    All this was tried with
    CONFIG_GROUP_SCHED=N
    CONFIG_RT_GROUP_SCHED=N


    Setting the options
    CONFIG_GROUP_SCHED=y
    CONFIG_RT_GROUP_SCHED=Y,
    seems to solve the problem.



    --
    -Thanks,Chirag


    \
     
     \ /
      Last update: 2008-09-25 14:41    [W:0.028 / U:0.048 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site