Could you send me the config used?
________________________________________
From: Fengguang Wu [fengguang.wu@xxxxxxxxx]
Sent: Thursday, February 07, 2013 8:05 PM
To: fengguang.wu@xxxxxxxxx; Viresh Kumar
Cc: Nathan Zimmer; cpufreq@xxxxxxxxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: cpufreq.c:1779 suspicious rcu_dereference_check() usage!
Greetings,
I got the below oops and the first bad commit is
commit 9d55504e3e713c03c5260302497a72cc10f87149
Author: Nathan Zimmer <nzimmer@xxxxxxx>
Date: Tue Feb 5 20:04:50 2013 -0600
cpufreq: Convert the cpufreq_driver_lock to use the rcu
In general rwlocks are discourged so we are moving it to use the rcu instead.
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Nathan Zimmer <nzimmer@xxxxxxx>
[ 1.572224]
[ 1.572419] ===============================
[ 1.572933] [ INFO: suspicious RCU usage. ]
[ 1.573464] 3.8.0-rc6-00407-gfe1080a #40 Not tainted
[ 1.574059] -------------------------------
[ 1.574559] /c/kernel-tests/src/stable/drivers/cpufreq/cpufreq.c:1779 suspicious rcu_dereference_check() usage!
[ 1.575759]
[ 1.575759] other info that might help us debug this:
[ 1.575759]
[ 1.576720]
[ 1.576720] rcu_scheduler_active = 1, debug_locks = 0
[ 1.577498] no locks held by swapper/0/1.
[ 1.577982]
[ 1.577982] stack backtrace:
[ 1.578533] Pid: 1, comm: swapper/0 Not tainted 3.8.0-rc6-00407-gfe1080a #40
[ 1.579373] Call Trace:
[ 1.579712] [<ffffffff8109d4ed>] lockdep_rcu_suspicious+0xfd/0x130
[ 1.580472] [<ffffffff81339528>] cpufreq_update_policy+0x168/0x1b0
[ 1.581233] [<ffffffff81027bb8>] ? kvm_clock_read+0x38/0x50
[ 1.581934] [<ffffffff8100aae9>] ? sched_clock+0x9/0x10
[ 1.582584] [<ffffffff81080925>] ? sched_clock_local+0x25/0xa0
[ 1.583297] [<ffffffff81080ad8>] ? sched_clock_cpu+0xa8/0x120
[ 1.584004] [<ffffffff813beec3>] ? mutex_lock_nested+0x2a3/0x380
[ 1.584739] [<ffffffff8109ae3d>] ? trace_hardirqs_off+0xd/0x10
[ 1.585444] [<ffffffff81080d0f>] ? local_clock+0x6f/0x80
[ 1.586104] [<ffffffff813bfc03>] ? __mutex_unlock_slowpath+0xd3/0x170
[ 1.586893] [<ffffffff8183da07>] ? cpufreq_core_init+0xc1/0xc1
[ 1.587603] [<ffffffff8109acdd>] ? trace_hardirqs_on_caller+0x10d/0x1a0
[ 1.588421] [<ffffffff8109ad7d>] ? trace_hardirqs_on+0xd/0x10
[ 1.589132] [<ffffffff813bfca9>] ? mutex_unlock+0x9/0x10
[ 1.589792] [<ffffffff81051b20>] ? cpu_maps_update_done+0x10/0x20
[ 1.590534] [<ffffffff8183da07>] ? cpufreq_core_init+0xc1/0xc1
[ 1.591252] [<ffffffff8183da66>] cpufreq_stats_init+0x5f/0xe5
[ 1.591970] [<ffffffff81812c91>] do_one_initcall+0x7a/0x139
[ 1.592660] [<ffffffff81812e53>] kernel_init_freeable+0x103/0x18d
[ 1.593393] [<ffffffff81812566>] ? do_early_param+0x8c/0x8c
[ 1.594086] [<ffffffff813a8a00>] ? rest_init+0x150/0x150
[ 1.594736] [<ffffffff813a8a09>] kernel_init+0x9/0xe0
[ 1.595389] [<ffffffff813c353c>] ret_from_fork+0x7c/0xb0
[ 1.596056] [<ffffffff813a8a00>] ? rest_init+0x150/0x150
[ 1.596707] cpuidle: using governor ladder
[ 1.597202] cpuidle: using governor menu
git bisect start fe1080a91b378aa68f16b377e048e9ae7bf9aa2d 1589a3e7777631ff56dd58cd7dcdf275185e62b5 --
git bisect good 4b794a03dc679a3ae545f683e47a6ef5e5e21d33 # 10 2013-02-06 20:22:16 Merge branch 'acpi-assorted' into linux-next
git bisect bad 39391e788192294c9fe58cd47ec7eb8ef5091b79 # 0 2013-02-06 20:37:42 Merge remote-tracking branch 'vireshk/cpufreq-updates' into devel-hive-x86_64-2013-02-06-17-16
git bisect good 16a44f82674ddd8d5b5b2527979ac22a25c55c50 # 10 2013-02-06 20:54:28 cpufreq: TEGRA: Set policy->cpus from driver->init()
git bisect good 6d50036dbaae080a1fb9376d4c4600b53b058d21 # 10 2013-02-06 21:24:44 Merge branch 'acpi-cleanup-next' into linux-next
git bisect good 85ada2c52ecce7963c0858eedead2063b9f18e75 # 10 2013-02-06 21:55:07 Merge branch 'pm-tools-next' into bleeding-edge
git bisect bad e62536d7877396c59e9eb5c52b470db6dbaf8ea1 # 0 2013-02-06 22:10:06 cpufreq: Add per policy governor-init/exit infrastructure
git bisect bad 9d55504e3e713c03c5260302497a72cc10f87149 # 0 2013-02-06 22:11:52 cpufreq: Convert the cpufreq_driver_lock to use the rcu
git bisect good 1184c024165b1e8de45f6fc9eb0cde336c2fa1f5 # 10 2013-02-06 22:29:14 cpufreq: Convert the cpufreq_driver_lock to a rwlock
git bisect good 1184c024165b1e8de45f6fc9eb0cde336c2fa1f5 # 30 2013-02-06 23:14:39 cpufreq: Convert the cpufreq_driver_lock to a rwlock
git bisect good 164708bec016c6ceb76a2bb2e29b086bf0ad4e37 # 30 2013-02-06 23:59:52 Add linux-next specific files for 20130204
Thanks,
Fengguang--
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