| Message ID | 20140217104821.21147.71463.stgit@srivatsabhat.in.ibm.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On 17 February 2014 16:18, Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> wrote: > The powernow-k8 driver maintains a per-cpu data-structure called powernow_data > that is used to perform the frequency transitions. It initializes this data- > structure only for the policy->cpu. So, accesses to this data-structure by > other CPUs results in various problems because they would have been > uninitialized. > > Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get() function, > it returns 0 as the KHz value, since its per-cpu memory doesn't point to > anything valid. This causes problems during suspend/resume since > cpufreq_update_policy() tries to enforce this (0 KHz) as the current frequency > of the CPU, and this madness gets propagated to adjust_jiffies() as well. > Eventually, lots of things start breaking down, including the r8169 ethernet > card, in one particularly interesting case reported by Pierre Ossman. > > https://bugzilla.kernel.org/show_bug.cgi?id=70311 > > Fix this by initializing the per-cpu data-structures of _all_ the CPUs > in the policy appropriately. > > Cc: stable@vger.kernel.org > Reported-by: Pierre Ossman <pierre@ossman.eu> > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> > --- > > drivers/cpufreq/powernow-k8.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index e10b646..6684e03 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > { > struct powernow_k8_data *data; > struct init_on_cpu init_on_cpu; > - int rc; > + int rc, cpu; > > smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); > if (rc) > @@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", > data->currfid, data->currvid); > > - per_cpu(powernow_data, pol->cpu) = data; > + /* Point all the CPUs in this policy to the same data */ > + for_each_cpu(cpu, pol->cpus) > + per_cpu(powernow_data, cpu) = data; > > return 0; > > @@ -1155,6 +1157,7 @@ err_out: > static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > { > struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); > + int cpu; > > if (!data) > return -EINVAL; > @@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > > kfree(data->powernow_table); > kfree(data); > - per_cpu(powernow_data, pol->cpu) = NULL; > + for_each_cpu(cpu, pol->cpus) > + per_cpu(powernow_data, cpu) = NULL; > > return 0; Acked-by: Viresh Kumar <viresh.kumar@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Monday, February 17, 2014 04:35:08 PM Viresh Kumar wrote: > On 17 February 2014 16:18, Srivatsa S. Bhat > <srivatsa.bhat@linux.vnet.ibm.com> wrote: > > The powernow-k8 driver maintains a per-cpu data-structure called powernow_data > > that is used to perform the frequency transitions. It initializes this data- > > structure only for the policy->cpu. So, accesses to this data-structure by > > other CPUs results in various problems because they would have been > > uninitialized. > > > > Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get() function, > > it returns 0 as the KHz value, since its per-cpu memory doesn't point to > > anything valid. This causes problems during suspend/resume since > > cpufreq_update_policy() tries to enforce this (0 KHz) as the current frequency > > of the CPU, and this madness gets propagated to adjust_jiffies() as well. > > Eventually, lots of things start breaking down, including the r8169 ethernet > > card, in one particularly interesting case reported by Pierre Ossman. > > > > https://bugzilla.kernel.org/show_bug.cgi?id=70311 > > > > Fix this by initializing the per-cpu data-structures of _all_ the CPUs > > in the policy appropriately. > > > > Cc: stable@vger.kernel.org > > Reported-by: Pierre Ossman <pierre@ossman.eu> > > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> > > --- > > > > drivers/cpufreq/powernow-k8.c | 10 +++++++--- > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > > index e10b646..6684e03 100644 > > --- a/drivers/cpufreq/powernow-k8.c > > +++ b/drivers/cpufreq/powernow-k8.c > > @@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > > { > > struct powernow_k8_data *data; > > struct init_on_cpu init_on_cpu; > > - int rc; > > + int rc, cpu; > > > > smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); > > if (rc) > > @@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > > pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", > > data->currfid, data->currvid); > > > > - per_cpu(powernow_data, pol->cpu) = data; > > + /* Point all the CPUs in this policy to the same data */ > > + for_each_cpu(cpu, pol->cpus) > > + per_cpu(powernow_data, cpu) = data; > > > > return 0; > > > > @@ -1155,6 +1157,7 @@ err_out: > > static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > > { > > struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); > > + int cpu; > > > > if (!data) > > return -EINVAL; > > @@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > > > > kfree(data->powernow_table); > > kfree(data); > > - per_cpu(powernow_data, pol->cpu) = NULL; > > + for_each_cpu(cpu, pol->cpus) > > + per_cpu(powernow_data, cpu) = NULL; > > > > return 0; > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Queued up as a fix for 3.14, thanks!
cc'ing stable for getting this in 3.12 and 3.13 as well.. On 17 February 2014 16:18, Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> wrote: > The powernow-k8 driver maintains a per-cpu data-structure called powernow_data > that is used to perform the frequency transitions. It initializes this data- > structure only for the policy->cpu. So, accesses to this data-structure by > other CPUs results in various problems because they would have been > uninitialized. > > Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get() function, > it returns 0 as the KHz value, since its per-cpu memory doesn't point to > anything valid. This causes problems during suspend/resume since > cpufreq_update_policy() tries to enforce this (0 KHz) as the current frequency > of the CPU, and this madness gets propagated to adjust_jiffies() as well. > Eventually, lots of things start breaking down, including the r8169 ethernet > card, in one particularly interesting case reported by Pierre Ossman. > > https://bugzilla.kernel.org/show_bug.cgi?id=70311 > > Fix this by initializing the per-cpu data-structures of _all_ the CPUs > in the policy appropriately. > > Cc: stable@vger.kernel.org > Reported-by: Pierre Ossman <pierre@ossman.eu> > Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> > --- > > drivers/cpufreq/powernow-k8.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index e10b646..6684e03 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > { > struct powernow_k8_data *data; > struct init_on_cpu init_on_cpu; > - int rc; > + int rc, cpu; > > smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); > if (rc) > @@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) > pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", > data->currfid, data->currvid); > > - per_cpu(powernow_data, pol->cpu) = data; > + /* Point all the CPUs in this policy to the same data */ > + for_each_cpu(cpu, pol->cpus) > + per_cpu(powernow_data, cpu) = data; > > return 0; > > @@ -1155,6 +1157,7 @@ err_out: > static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > { > struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); > + int cpu; > > if (!data) > return -EINVAL; > @@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) > > kfree(data->powernow_table); > kfree(data); > - per_cpu(powernow_data, pol->cpu) = NULL; > + for_each_cpu(cpu, pol->cpus) > + per_cpu(powernow_data, cpu) = NULL; > > return 0; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index e10b646..6684e03 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) { struct powernow_k8_data *data; struct init_on_cpu init_on_cpu; - int rc; + int rc, cpu; smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); if (rc) @@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", data->currfid, data->currvid); - per_cpu(powernow_data, pol->cpu) = data; + /* Point all the CPUs in this policy to the same data */ + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = data; return 0; @@ -1155,6 +1157,7 @@ err_out: static int powernowk8_cpu_exit(struct cpufreq_policy *pol) { struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); + int cpu; if (!data) return -EINVAL; @@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) kfree(data->powernow_table); kfree(data); - per_cpu(powernow_data, pol->cpu) = NULL; + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = NULL; return 0; }
The powernow-k8 driver maintains a per-cpu data-structure called powernow_data that is used to perform the frequency transitions. It initializes this data- structure only for the policy->cpu. So, accesses to this data-structure by other CPUs results in various problems because they would have been uninitialized. Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get() function, it returns 0 as the KHz value, since its per-cpu memory doesn't point to anything valid. This causes problems during suspend/resume since cpufreq_update_policy() tries to enforce this (0 KHz) as the current frequency of the CPU, and this madness gets propagated to adjust_jiffies() as well. Eventually, lots of things start breaking down, including the r8169 ethernet card, in one particularly interesting case reported by Pierre Ossman. https://bugzilla.kernel.org/show_bug.cgi?id=70311 Fix this by initializing the per-cpu data-structures of _all_ the CPUs in the policy appropriately. Cc: stable@vger.kernel.org Reported-by: Pierre Ossman <pierre@ossman.eu> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> --- drivers/cpufreq/powernow-k8.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html