lkml.org 
[lkml]   [2006]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [patch 00/61] ANNOUNCE: lock validator -V1
    From
    Date

    > I'm feeling a bit overwhelmed by the voluminous output of this checker.
    > Especially as (directly at least) cpufreq doesn't touch vma's, or mmap's.

    the reporter doesn't have CONFIG_KALLSYMS_ALL enabled which gives
    sometimes misleading backtraces (should lockdep just enable KALLSYMS_ALL
    to get more useful bugreports?)

    the problem is this, there are 2 scenarios in this bug:

    One
    ---
    store_scaling_governor takes policy->lock and then calls __cpufreq_set_policy
    __cpufreq_set_policy calls __cpufreq_governor
    __cpufreq_governor calls __cpufreq_driver_target via cpufreq_governor_performance
    __cpufreq_driver_target calls lock_cpu_hotplug() (which takes the hotplug lock)


    Two
    ---
    cpufreq_stats_init lock_cpu_hotplug() and then calls cpufreq_stat_cpu_callback
    cpufreq_stat_cpu_callback calls cpufreq_update_policy
    cpufreq_update_policy takes the policy->lock


    so this looks like a real honest AB-BA deadlock to me...


    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-05-30 07:48    [W:4.540 / U:0.364 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site