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authorAndrea Righi <righi.andrea@gmail.com>2008-09-18 10:43:40 +0000
committerDave Jones <davej@redhat.com>2008-10-09 13:52:44 -0400
commit4f6e6b9f97b0ce98a8d1da65adbaf743bd0486a9 (patch)
treeb50dcdfa6ee6249af1be8549acbe459a452deb55 /drivers/cpufreq
parentc4d14bc0bb5d13e316890651ae4518b764c3344c (diff)
[CPUFREQ] Fix BUG: using smp_processor_id() in preemptible code
Use get_cpu()/put_cpu() in cpufreq_ondemand init routine, instead of smp_processor_id() to avoid the following BUG: [ 35.313118] BUG: using smp_processor_id() in preemptible [00000000] code=: modprobe/4952 [ 35.313132] caller is cpufreq_gov_dbs_init+0xa/0x8f [cpufreq_ondemand] [ 35.313140] Pid: 4952, comm: modprobe Not tainted 2.6.27-rc5-mm1 #23 [ 35.313145] Call Trace: [ 35.313158] [<ffffffff80361ff7>] debug_smp_processor_id+0xd7/0xe0 [ 35.313167] [<ffffffffa010800a>] cpufreq_gov_dbs_init+0xa/0x8f [cpufreq_ondemand] [ 35.313176] [<ffffffff8020903b>] _stext+0x3b/0x160 [ 35.313185] [<ffffffff804768c5>] __mutex_unlock_slowpath+0xe5/0x190 [ 35.313195] [<ffffffff8026236a>] trace_hardirqs_on_caller+0xca/0x140 [ 35.313205] [<ffffffff8026ef4c>] sys_init_module+0xdc/0x210 [ 35.313212] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index bd069349bcae..2ab3c12b88af 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -640,8 +640,11 @@ static int __init cpufreq_gov_dbs_init(void)
{
int err;
cputime64_t wall;
- u64 idle_time = get_cpu_idle_time_us(smp_processor_id(), &wall);
+ u64 idle_time;
+ int cpu = get_cpu();
+ idle_time = get_cpu_idle_time_us(cpu, &wall);
+ put_cpu();
if (idle_time != -1ULL) {
/* Idle micro accounting is supported. Use finer thresholds */
dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;