'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) }
data->table = table; - per_cpu(cpu_data, cpu) = data;
/* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
We are copying cpu_core_mask(cpu) in a per-cpu local variable: 'cpu_mask'. There is no need of doing this and can be replaced by a call to cpu_core_mask().
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/ppc-corenet-cpufreq.c | 26 +++----------------------- 1 file changed, 3 insertions(+), 23 deletions(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index bee5df7..dbcac39 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -69,9 +69,6 @@ static const u32 *fmask;
static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
-/* cpumask in a cluster */ -static DEFINE_PER_CPU(cpumask_var_t, cpu_mask); - #ifndef CONFIG_SMP static inline const struct cpumask *cpu_core_mask(int cpu) { @@ -201,8 +198,8 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) data->table = table;
/* update ->cpus if we have cluster, no harm if not */ - cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu)); - for_each_cpu(i, per_cpu(cpu_mask, cpu)) + cpumask_copy(policy->cpus, cpu_core_mask(cpu)); + for_each_cpu(i, cpu_core_mask(cpu)) per_cpu(cpu_data, i) = data;
/* Minimum transition latency is 12 platform clocks */ @@ -236,7 +233,7 @@ static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy) kfree(data->table); kfree(data);
- for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu)) + for_each_cpu(cpu, cpu_core_mask(policy->cpu)) per_cpu(cpu_data, cpu) = NULL;
return 0; @@ -285,12 +282,6 @@ static int __init ppc_corenet_cpufreq_init(void) if (!np) return -ENODEV;
- for_each_possible_cpu(cpu) { - if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL)) - goto err_mask; - cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu)); - } - match = of_match_node(node_matches, np); data = match->data; if (data) { @@ -308,22 +299,11 @@ static int __init ppc_corenet_cpufreq_init(void) pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
return ret; - -err_mask: - for_each_possible_cpu(cpu) - free_cpumask_var(per_cpu(cpu_mask, cpu)); - - return -ENOMEM; } module_init(ppc_corenet_cpufreq_init);
static void __exit ppc_corenet_cpufreq_exit(void) { - unsigned int cpu; - - for_each_possible_cpu(cpu) - free_cpumask_var(per_cpu(cpu_mask, cpu)); - cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver); } module_exit(ppc_corenet_cpufreq_exit);
Hello Viresh:
Probably it is not right considering the CPU cluster and CPU hotplug case.
Hongtao: Please verify it on t4240 platform which have cluster.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 11:41 AM To: Rafael Wysocki; Tang Yuantian-B29983 Cc: linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472; Viresh Kumar Subject: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
We are copying cpu_core_mask(cpu) in a per-cpu local variable: 'cpu_mask'. There is no need of doing this and can be replaced by a call to cpu_core_mask().
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
drivers/cpufreq/ppc-corenet-cpufreq.c | 26 +++----------------------- 1 file changed, 3 insertions(+), 23 deletions(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index bee5df7..dbcac39 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -69,9 +69,6 @@ static const u32 *fmask;
static DEFINE_PER_CPU(struct cpu_data *, cpu_data);
-/* cpumask in a cluster */ -static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);
#ifndef CONFIG_SMP static inline const struct cpumask *cpu_core_mask(int cpu) { @@ -201,8 +198,8 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) data->table = table;
/* update ->cpus if we have cluster, no harm if not */
- cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
- for_each_cpu(i, per_cpu(cpu_mask, cpu))
cpumask_copy(policy->cpus, cpu_core_mask(cpu));
for_each_cpu(i, cpu_core_mask(cpu)) per_cpu(cpu_data, i) = data;
/* Minimum transition latency is 12 platform clocks */ @@ -236,7 +233,7
@@ static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy) kfree(data->table); kfree(data);
- for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
for_each_cpu(cpu, cpu_core_mask(policy->cpu)) per_cpu(cpu_data, cpu) = NULL;
return 0;
@@ -285,12 +282,6 @@ static int __init ppc_corenet_cpufreq_init(void) if (!np) return -ENODEV;
- for_each_possible_cpu(cpu) {
if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))goto err_mask;cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));- }
- match = of_match_node(node_matches, np); data = match->data; if (data) {
@@ -308,22 +299,11 @@ static int __init ppc_corenet_cpufreq_init(void) pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");
return ret;
-err_mask:
- for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_mask, cpu));- return -ENOMEM;
} module_init(ppc_corenet_cpufreq_init);
static void __exit ppc_corenet_cpufreq_exit(void) {
- unsigned int cpu;
- for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_mask, cpu));- cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
} module_exit(ppc_corenet_cpufreq_exit); -- 2.0.3.693.g996b0fd
On 2 September 2014 12:16, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Hello Viresh:
Probably it is not right considering the CPU cluster and CPU hotplug case.
So in case of hotplug the worst that can happen is policy->cpu gets updated. But because we are all concerned about cpu_data here, which is stored in per-cpu variables and is updated for all online CPUs, it should work.
I would like to see how that fails :)
I am saying your patch 2 probably is wrong, not patch 1. Consider following case: On T4240 platform, we have 3 cluster with 8 cpu in each cluster. We offline 4 5 6 7 cpu and then online them back. Cpu 4's policy->cpus is 0, 1, 2, 3, 4 Cpu 5's policy->cpus is 0, 1, 2, 3, 4, 5. .... So cpu 4 and 5's policy->cpus are not right, they should be 0, 1, 2, 3, 4, 5, 6, 7.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 2:49 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 2 September 2014 12:16, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Hello Viresh:
Probably it is not right considering the CPU cluster and CPU hotplug case.
So in case of hotplug the worst that can happen is policy->cpu gets updated. But because we are all concerned about cpu_data here, which is stored in per-cpu variables and is updated for all online CPUs, it should work.
I would like to see how that fails :)
On 2 September 2014 12:32, Yuantian Tang Yuantian.Tang@freescale.com wrote:
I am saying your patch 2 probably is wrong, not patch 1.
Okay, it looked initially that both are screwed up :)
Consider following case: On T4240 platform, we have 3 cluster with 8 cpu in each cluster. We offline 4 5 6 7 cpu and then online them back.
i.e. last four CPUs of first cluster..
Cpu 4's policy->cpus is 0, 1, 2, 3, 4 Cpu 5's policy->cpus is 0, 1, 2, 3, 4, 5.
How? And how is this patch going to touch policy->cpus? CPU 0-7 should be sharing a single 'struct cpufreq_policy' and so policy->cpus should be same for all..
If policy->cpus is same for all cpus in a cluster that should not be a problem. Probably there's something else that need to check. I have feelings that your patch may not be correct. I hope it works though.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 3:10 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 2 September 2014 12:32, Yuantian Tang Yuantian.Tang@freescale.com wrote:
I am saying your patch 2 probably is wrong, not patch 1.
Okay, it looked initially that both are screwed up :)
Consider following case: On T4240 platform, we have 3 cluster with 8 cpu in each cluster. We offline 4 5 6 7 cpu and then online them back.
i.e. last four CPUs of first cluster..
Cpu 4's policy->cpus is 0, 1, 2, 3, 4 Cpu 5's policy->cpus is 0, 1, 2, 3, 4, 5.
How? And how is this patch going to touch policy->cpus? CPU 0-7 should be sharing a single 'struct cpufreq_policy' and so policy->cpus should be same for all..
Hello Viresh,
Test confirmed what I am concerned. Patch 1 is working but patch 2 didn't working in hotplug case. (tested on t4240 platform with 3 cluster and 8 cpus in each cluster, kernel version is 3.12).
Log is as follows: root@t4240rdb:~# cd /sys/devices/system/ root@t4240rdb:/sys/devices/system# ls clockevents clocksource cpu edac root@t4240rdb:/sys/devices/system# cd cpu/ root@t4240rdb:/sys/devices/system/cpu# ls cpu0 cpu1 cpu10 cpu11 cpu12 cpu13 cpu14 cpu15 cpu16 cpu17 cpu18 cpu19 cpu2 cpu20 cpu21 cpu22 cpu23 cpu3 cpu4cpu5 cpu6 cpu7 cpu8 cpu9 kernel_max offline online possible present probe release uevent root@t4240rdb:/sys/devices/system/cpu# cat cpu8/ altivec_idle altivec_idle_wait_time cache/ cpufreq/ online physical_id pir pw20_state pw20_wait_time smt_snooze_delay subsystem/ topology/ uevent root@t4240rdb:/sys/devices/system/cpu# cat cpu8/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu8/online Cannot set affinity for irq 467 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu9/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu11/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu12/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu13/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu14/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu15/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu9/online smp_85xx_kick_cpu: Can not start CPU #9. Start CPU #8 first. smp: failed starting cpu 9 (rc -2) -sh: echo: write error: No such file or directory root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu11/online sysfs: cannot create duplicate filename '/devices/system/cpu/cpu10/cpufreq' ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:526 Modules linked in: CPU: 18 PID: 2658 Comm: sh Not tainted 3.12.19-rt30-00018-g7eac4c0-dirty #2 task: c00000015fa0b440 ti: c00000007a54c000 task.ti: c00000007a54c000 NIP: c00000000018ea34 LR: c00000000018ea30 CTR: c000000000304330 REGS: c00000007a54f340 TRAP: 0700 Not tainted (3.12.19-rt30-00018-g7eac4c0-dirty) MSR: 0000000080029000 <CE,EE,ME> CR: 44222444 XER: 20000000 SOFTE: 1
GPR00: c00000000018ea30 c00000007a54f5c0 c000000000b4d1a0 000000000000004b GPR04: 0000000044222444 c000000009620e70 0000000000000008 0000000000000008 GPR08: 0000000000000000 0000000000000001 80000800803b8500 0000000000000000 GPR12: 0000000024222442 c00000000fffc700 0000000000000000 00000000100e0000 GPR16: 00000000100daea4 00000000100e0000 c0000000009738b8 c000000179a29e58 GPR20: c000000000a42680 c000000000c0d1a0 c000000000b57c20 c000000000b57600 GPR24: 0000000000000000 c000000000a789e0 0000000000000001 0000000000000000 GPR28: c00000017545c000 c00000007a54f6c0 c000000179962278 ffffffffffffffef NIP [c00000000018ea34] .sysfs_add_one+0xd0/0xec LR [c00000000018ea30] .sysfs_add_one+0xcc/0xec Call Trace: [c00000007a54f5c0] [c00000000018ea30] .sysfs_add_one+0xcc/0xec (unreliable) [c00000007a54f650] [c00000000018faf8] .sysfs_do_create_link_sd+0xfc/0x2bc [c00000007a54f700] [c00000000056468c] .__cpufreq_add_dev.isra.24+0x728/0x768 [c00000007a54f7e0] [c000000000564758] .cpufreq_cpu_callback+0x84/0x108 [c00000007a54f860] [c000000000067218] .notifier_call_chain+0x80/0xe8 [c00000007a54f900] [c00000000003be20] .__cpu_notify+0x34/0x78 [c00000007a54f970] [c00000000003c5cc] .cpu_up+0x194/0x1e4 [c00000007a54fa20] [c0000000005f6318] .cpu_subsys_online+0x24/0x4c [c00000007a54fab0] [c0000000003173dc] .device_online+0xa4/0x104 [c00000007a54fb40] [c0000000003174c4] .online_store+0x88/0x90 [c00000007a54fbd0] [c0000000003143d0] .dev_attr_store+0x30/0x4c [c00000007a54fc40] [c00000000018c98c] .sysfs_write_file+0xe8/0x1ac [c00000007a54fcf0] [c00000000011324c] .vfs_write+0xe8/0x21c [c00000007a54fd90] [c000000000113858] .SyS_write+0x58/0xcc [c00000007a54fe30] [c000000000000598] syscall_exit+0x0/0x8c Instruction dump: 4810e775 60000000 e89e0010 7f83e378 38a01000 4810e761 60000000 7f84e378 3c62ffde 38630e60 485b3755 60000000 <0fe00000> 7f83e378 4bf7d43d 60000000 ---[ end trace 275aa88102f60f48 ]--- root@t4240rdb:/sys/devices/system/cpu#
the original driver is OK, the log is: t4240rdb login: root root@t4240rdb:~# root@t4240rdb:~# root@t4240rdb:~# root@t4240rdb:~# cd /sys/devices/system/cpu/ root@t4240rdb:/sys/devices/system/cpu# cat cpu8/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu8/online Cannot set affinity for irq 467 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu9/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu11/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu12/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu13/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu14/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu15/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu14/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu15/online root@t4240rdb:/sys/devices/system/cpu# cat cpu14/cpufreq/affected_cpus 14 15 root@t4240rdb:/sys/devices/system/cpu# cat cpu15/cpufreq/affected_cpus 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu12/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu13/online root@t4240rdb:/sys/devices/system/cpu# cat cpu15/cpufreq/affected_cpus 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu11/online root@t4240rdb:/sys/devices/system/cpu# cat cpu15/cpufreq/affected_cpus 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu8/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu9/online root@t4240rdb:/sys/devices/system/cpu# cat cpu15/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# cat cpu9/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# root@t4240rdb:/sys/devices/system/cpu# uname -a Linux t4240rdb 3.12.19-rt30-00018-g7eac4c0-dirty #4 SMP Wed Sep 3 14:56:49 CST 2014 ppc64 GNU/Linux root@t4240rdb:/sys/devices/system/cpu#
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 3:10 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 2 September 2014 12:32, Yuantian Tang Yuantian.Tang@freescale.com wrote:
I am saying your patch 2 probably is wrong, not patch 1.
Okay, it looked initially that both are screwed up :)
Consider following case: On T4240 platform, we have 3 cluster with 8 cpu in each cluster. We offline 4 5 6 7 cpu and then online them back.
i.e. last four CPUs of first cluster..
Cpu 4's policy->cpus is 0, 1, 2, 3, 4 Cpu 5's policy->cpus is 0, 1, 2, 3, 4, 5.
How? And how is this patch going to touch policy->cpus? CPU 0-7 should be sharing a single 'struct cpufreq_policy' and so policy->cpus should be same for all..
On 3 September 2014 13:32, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Test confirmed what I am concerned. Patch 1 is working but patch 2 didn't working in hotplug case. (tested on t4240 platform with 3 cluster and 8 cpus in each cluster, kernel version is 3.12).
:(
Log is as follows: root@t4240rdb:~# cd /sys/devices/system/ root@t4240rdb:/sys/devices/system# ls clockevents clocksource cpu edac root@t4240rdb:/sys/devices/system# cd cpu/ root@t4240rdb:/sys/devices/system/cpu# ls cpu0 cpu1 cpu10 cpu11 cpu12 cpu13 cpu14 cpu15 cpu16 cpu17 cpu18 cpu19 cpu2 cpu20 cpu21 cpu22 cpu23 cpu3 cpu4cpu5 cpu6 cpu7 cpu8 cpu9 kernel_max offline online possible present probe release uevent root@t4240rdb:/sys/devices/system/cpu# cat cpu8/ altivec_idle altivec_idle_wait_time cache/ cpufreq/ online physical_id pir pw20_state pw20_wait_time smt_snooze_delay subsystem/ topology/ uevent root@t4240rdb:/sys/devices/system/cpu# cat cpu8/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu8/online Cannot set affinity for irq 467 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu9/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu11/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu12/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu13/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu14/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu15/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu9/online smp_85xx_kick_cpu: Can not start CPU #9. Start CPU #8 first. smp: failed starting cpu 9 (rc -2) -sh: echo: write error: No such file or directory
I don't understand how is this related to my patch? And the successful sequence below has CPU14 here instead of 8.. So this error might come without my patch as well if this sequence is followed..
root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu11/online sysfs: cannot create duplicate filename '/devices/system/cpu/cpu10/cpufreq' ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:526
I think I know why this happened.
Does cpu_core_mask() gives mask of ONLY Online CPUs ? I *strongly* believe YES looking at above crash.
If we can change that with some other routine which gives mask of all (online+offline) CPUs then this crash might go away..
Because of that, I believe there is another problem in your driver even without my patch. Do this to get similar crash:
- build driver as module and don't load it by default - boot your system - offline CPUs 8 to 15 as you did above. - insert module - try to online cores as you did above.
-- viresh
Can't agree you more. As I know, there is no such function to get mask of online and offline cpus in a cluster.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Wednesday, September 03, 2014 5:50 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Li Yang-Leo-R58472; Jia Hongtao-B38951 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 3 September 2014 13:32, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Test confirmed what I am concerned. Patch 1 is working but patch 2 didn't
working in hotplug case.
(tested on t4240 platform with 3 cluster and 8 cpus in each cluster, kernel
version is 3.12).
:(
Log is as follows: root@t4240rdb:~# cd /sys/devices/system/ root@t4240rdb:/sys/devices/system# ls clockevents clocksource cpu edac root@t4240rdb:/sys/devices/system# cd cpu/ root@t4240rdb:/sys/devices/system/cpu# ls cpu0 cpu1 cpu10 cpu11 cpu12 cpu13 cpu14 cpu15 cpu16
cpu17
cpu18 cpu19 cpu2 cpu20 cpu21 cpu22 cpu23 cpu3 cpu4cpu5
cpu6 cpu7 cpu8 cpu9 kernel_max offline online possible present probe release uevent root@t4240rdb:/sys/devices/system/cpu# cat cpu8/
altivec_idle altivec_idle_wait_time cache/
cpufreq/ online physical_id pir pw20_state pw20_wait_time smt_snooze_delay subsystem/ topology/ uevent
root@t4240rdb:/sys/devices/system/cpu# cat cpu8/cpufreq/affected_cpus 8 9 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu8/online Cannot set affinity for irq 467 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu9/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 11 12 13 14 15 root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu11/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu12/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu13/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu14/online root@t4240rdb:/sys/devices/system/cpu# echo 0 > cpu15/online root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu9/online smp_85xx_kick_cpu: Can not start CPU #9. Start CPU #8 first. smp: failed starting cpu 9 (rc -2) -sh: echo: write error: No such file or directory
I don't understand how is this related to my patch? And the successful sequence below has CPU14 here instead of 8.. So this error might come without my patch as well if this sequence is followed..
root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu10/online root@t4240rdb:/sys/devices/system/cpu# cat cpu10/cpufreq/affected_cpus 10 root@t4240rdb:/sys/devices/system/cpu# echo 1 > cpu11/online sysfs: cannot create duplicate filename '/devices/system/cpu/cpu10/cpufreq' ------------[ cut here ]------------ WARNING: at fs/sysfs/dir.c:526
I think I know why this happened.
Does cpu_core_mask() gives mask of ONLY Online CPUs ? I *strongly* believe YES looking at above crash.
If we can change that with some other routine which gives mask of all (online+offline) CPUs then this crash might go away..
Because of that, I believe there is another problem in your driver even without my patch. Do this to get similar crash:
- build driver as module and don't load it by default
- boot your system
- offline CPUs 8 to 15 as you did above.
- insert module
- try to online cores as you did above.
-- viresh
On 4 September 2014 08:21, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Can't agree you more.
Its not about upstreaming my patch but doing the right thing.
As I know, there is no such function to get mask of online and offline cpus in a cluster.
This is a primary requirement of cpufreq-subsystem. The ->init() callback must initialize policy->cpus to the mask of all online+offline CPUs that are sharing clock.
Okay, then what I can say is your driver is already broken (without my patch) when we use it as a module.
- build driver as module and don't load it by default
- boot your system
- offline CPUs 8 to 15 as you did above.
- insert module
- try to online cores as you did above.
Above sequence of events would reproduce similar crash for you. So, either fix this problem or mark your module as 'bool' instead of 'tristate' so that it can't be compiled as module anymore.
-- viresh
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Thursday, September 04, 2014 11:38 AM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Li Yang-Leo-R58472; Jia Hongtao-B38951 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 4 September 2014 08:21, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Can't agree you more.
Its not about upstreaming my patch but doing the right thing.
As I know, there is no such function to get mask of online and offline cpus in a
cluster.
This is a primary requirement of cpufreq-subsystem. The ->init() callback must initialize policy->cpus to the mask of all online+offline CPUs that are sharing clock.
Okay, then what I can say is your driver is already broken (without my patch) when we use it as a module.
- build driver as module and don't load it by default
- boot your system
- offline CPUs 8 to 15 as you did above.
- insert module
- try to online cores as you did above.
Above sequence of events would reproduce similar crash for you. So, either fix this problem or mark your module as 'bool' instead of 'tristate' so that it can't be compiled as module anymore.
What about the other arch? Can they deal with this situation?
Thanks, Yuantian
-- viresh
On 4 September 2014 10:03, Yuantian Tang Yuantian.Tang@freescale.com wrote:
What about the other arch? Can they deal with this situation?
Yes for most of them (speacially ARM), because they fulfill the requirement of CPUFreq core. i.e. set policy->cpus to all online+offline CPUs.
OK, I see. Seems like we don't have choice but make it bool. I will try to make it better later.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Thursday, September 04, 2014 12:37 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Li Yang-Leo-R58472; Jia Hongtao-B38951 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 4 September 2014 10:03, Yuantian Tang Yuantian.Tang@freescale.com wrote:
What about the other arch? Can they deal with this situation?
Yes for most of them (speacially ARM), because they fulfill the requirement of CPUFreq core. i.e. set policy->cpus to all online+offline CPUs.
On 4 September 2014 13:13, Yuantian Tang Yuantian.Tang@freescale.com wrote:
OK, I see. Seems like we don't have choice but make it bool.
I am quite surprised that the architecture doesn't provide such macros.
I have added few powerpc guys (Mostly Maintainers) to check what would it take to get such a macro..
What we want: A routine/macro that returns mask of all CPUs/threads sharing clock line. cpu_core_mask() gives something similar but only for online CPUs, and we want that for online+offline CPUs.
Btw, another powerpc driver is doing this: drivers/cpufreq/powernv-cpufreq.c
base = cpu_first_thread_sibling(policy->cpu); for (i = 0; i < threads_per_core; i++) cpumask_set_cpu(base + i, policy->cpus);
Will this work for you as well ?
On Thu, 2014-09-04 at 13:22 +0530, Viresh Kumar wrote:
On 4 September 2014 13:13, Yuantian Tang Yuantian.Tang@freescale.com wrote:
OK, I see. Seems like we don't have choice but make it bool.
I am quite surprised that the architecture doesn't provide such macros.
I have added few powerpc guys (Mostly Maintainers) to check what would it take to get such a macro..
What we want: A routine/macro that returns mask of all CPUs/threads sharing clock line.
What do you mean by "clock line" ? This is a very .... odd concept here. On P8 we have a reference clock (well several) going into the package, which can contain multiple dies, which contain multiple cores which can operate at different frequencies but it's not really a "clock line".
And every implementation out there would do things differently. I don't know what Freescale does but you can't compare.
The architecture doesn't provide such a macro because the link between cpufreq entity is a cpufreq specific concept. For example we could have a chip where cores have pstate by pairs but otherwise are completely independent. So it's up to the cpufreq driver for the given platform to handle that.
I don't see how we could provide a "macro" ... we might be able to represent the pstate domains in some way and provide some kind of architecture function for that but it wouldn't be a macro. It happens that today on P8 we control the pstates per core but that might not be always the case for example.
cpu_core_mask() gives something similar but only for online CPUs, and we want that for online+offline CPUs.
Correct.
Btw, another powerpc driver is doing this: drivers/cpufreq/powernv-cpufreq.c
base = cpu_first_thread_sibling(policy->cpu); for (i = 0; i < threads_per_core; i++) cpumask_set_cpu(base + i, policy->cpus);
Will this work for you as
That's P8 native. It currently use the core as the entity but that probably needs to be improved based on some device-tree property for long term solidity.
Ben.
well ?
On 4 September 2014 13:29, Benjamin Herrenschmidt benh@kernel.crashing.org wrote:
What do you mean by "clock line" ? This is a very .... odd concept here.
We want to know which CPUs change their P-state together. As cpufreq considers that as a group (represented by a single struct cpufreq_policy). And while changing frequency of a core, cpufreq governors look at the load of all CPUs within that group and chooses the frequency that satisfies the CPU with highest load.
The architecture doesn't provide such a macro because the link between cpufreq entity is a cpufreq specific concept. For example we could have a chip where cores have pstate by pairs but otherwise are completely
You meant the possible p-states for CPUs are same but they change it separately?
If yes, then this isn't what I meant by a single clock-line..
I don't see how we could provide a "macro" ... we might be able to represent the pstate domains in some way and provide some kind of architecture function for that but it wouldn't be a macro. It happens that today on P8 we control the pstates per core but that might not be always the case for example.
I see. But a cpufreq-driver like "ppc-corenet-cpufreq.c" should be able to get which all CPUs change p-states together, just like powernv..
And that's what we wanted to know for this driver.
Btw, another powerpc driver is doing this: drivers/cpufreq/powernv-cpufreq.c
base = cpu_first_thread_sibling(policy->cpu); for (i = 0; i < threads_per_core; i++) cpumask_set_cpu(base + i, policy->cpus);
Will this work for you as
That's P8 native. It currently use the core as the entity but that probably needs to be improved based on some device-tree property for long term solidity.
I see..
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Thursday, September 04, 2014 12:37 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Li Yang-Leo-R58472; Jia Hongtao-B38951 Subject: Re: [PATCH 2/2] cpufreq: ppc-corenet: remove per-cpu variable 'cpu_mask'
On 4 September 2014 10:03, Yuantian Tang Yuantian.Tang@freescale.com wrote:
What about the other arch? Can they deal with this situation?
Yes for most of them (speacially ARM), because they fulfill the requirement of CPUFreq core. i.e. set policy->cpus to all online+offline CPUs.
What's the name of function on ARM arch which get the mask of all online and offline cpus?
We want this driver to be used on ARM as well. So how to write the Kconfig, as you know we already have a CONFIG_* item in Kconfig.powerpc.
Thanks, Yuantian
On 5 September 2014 15:05, Yuantian Tang Yuantian.Tang@freescale.com wrote:
What's the name of function on ARM arch which get the mask of all online and offline cpus?
You can have a look at arm_big_little.c for this, its topology_core_cpumask().
Also, this might not work for everybody and so we are trying to get this information from DT, but it is taking some time to get the bindings correctly.
We want this driver to be used on ARM as well. So how to write the Kconfig, as you know we already have a CONFIG_* item in Kconfig.powerpc.
Just duplicate them.
Hello Viresh:
I am not sure if this is right in CPU hotplug case.
Hongtao: Please verify this in CPU hotplug case.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 11:41 AM To: Rafael Wysocki; Tang Yuantian-B29983 Cc: linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472; Viresh Kumar Subject: [PATCH 1/2] cpufreq: ppc-corenet: remove duplicate update of cpu_data
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well policy->and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) }
data->table = table;
per_cpu(cpu_data, cpu) = data;
/* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
-- 2.0.3.693.g996b0fd
On 2 September 2014 12:08, Yuantian Tang Yuantian.Tang@freescale.com wrote:
Hello Viresh:
I am not sure if this is right in CPU hotplug case.
policy->cpus must have all the online CPUs and so it should work for all online CPUs. what's your doubt?
On 2 September 2014 09:11, Viresh Kumar viresh.kumar@linaro.org wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) }
data->table = table;
per_cpu(cpu_data, cpu) = data; /* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
Hi Yuantian,
Can we get your Ack for this patch atleast so that Rafael can apply it ?
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Wednesday, September 10, 2014 12:33 PM To: Rafael Wysocki; Tang Yuantian-B29983 Cc: Lists linaro-kernel; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472; Viresh Kumar Subject: Re: [PATCH 1/2] cpufreq: ppc-corenet: remove duplicate update of cpu_data
On 2 September 2014 09:11, Viresh Kumar viresh.kumar@linaro.org wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as policy->well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct
cpufreq_policy *policy)
} data->table = table;
per_cpu(cpu_data, cpu) = data; /* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));Hi Yuantian,
Can we get your Ack for this patch atleast so that Rafael can apply it ?
Yeah, your patch should be ok, but is it the best solution? I was thinking about a final solution just like ARM did.
Thanks, Yuantian
On 10 September 2014 11:00, Yuantian Tang Yuantian.Tang@freescale.com wrote:
On 2 September 2014 09:11, Viresh Kumar viresh.kumar@linaro.org wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as policy->well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Yeah, your patch should be ok, but is it the best solution? I was thinking about a final solution just like ARM did.
I was talking about an Ack for just 1/2 where we are doing some cleanup, which shouldn't break anything.
Regarding the second patch, yes you should come up with something that can give a list of online+offline CPUs like ARM and even some ppc drivers. We can handle that separately and this patch can be commited by Rafael..
Either you can give a replacement patch for 2/2 or you can let me know what to do and will help there.
Ok, sure.
Thanks, Yuantian
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Wednesday, September 10, 2014 1:39 PM To: Tang Yuantian-B29983 Cc: Rafael Wysocki; Lists linaro-kernel; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472 Subject: Re: [PATCH 1/2] cpufreq: ppc-corenet: remove duplicate update of cpu_data
On 10 September 2014 11:00, Yuantian Tang Yuantian.Tang@freescale.com wrote:
On 2 September 2014 09:11, Viresh Kumar viresh.kumar@linaro.org wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as policy->well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Yeah, your patch should be ok, but is it the best solution? I was thinking about a final solution just like ARM did.
I was talking about an Ack for just 1/2 where we are doing some cleanup, which shouldn't break anything.
Regarding the second patch, yes you should come up with something that can give a list of online+offline CPUs like ARM and even some ppc drivers. We can handle that separately and this patch can be commited by Rafael..
Either you can give a replacement patch for 2/2 or you can let me know what to do and will help there.
-----Original Message----- From: Viresh Kumar [mailto:viresh.kumar@linaro.org] Sent: Tuesday, September 02, 2014 11:41 AM To: Rafael Wysocki; Tang Yuantian-B29983 Cc: linaro-kernel@lists.linaro.org; linux-pm@vger.kernel.org; Zhang Hongbo-B45939; Li Yang-Leo-R58472; Viresh Kumar Subject: [PATCH 1/2] cpufreq: ppc-corenet: remove duplicate update of cpu_data
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well policy->and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) }
data->table = table;
per_cpu(cpu_data, cpu) = data;
/* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
-- 2.0.3.693.g996b0fd
Acked-by: Tang Yuantian Yuantian.Tang@freescale.com
Regards, Yuantian
On Tuesday, September 02, 2014 09:11:24 AM Viresh Kumar wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
I'm not sure about the status here?
Hi Yuantian,
I was looking into this driver due to issues reported by Hongtao (cc'd) and found that we can live without some code. These aren't fixing any bugs and are just cleanups.
I didn't had a compiler for this and so this isn't even compiled. It would be great if you can please review/test these patches.
drivers/cpufreq/ppc-corenet-cpufreq.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c index 3607070..bee5df7 100644 --- a/drivers/cpufreq/ppc-corenet-cpufreq.c +++ b/drivers/cpufreq/ppc-corenet-cpufreq.c @@ -199,7 +199,6 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy) } data->table = table;
- per_cpu(cpu_data, cpu) = data;
/* update ->cpus if we have cluster, no harm if not */ cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
On 24 September 2014 16:45, Rafael J. Wysocki rjw@rjwysocki.net wrote:
On Tuesday, September 02, 2014 09:11:24 AM Viresh Kumar wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
I'm not sure about the status here?
Apply only the first patch (1/2) with
Acked-by: Tang Yuantian Yuantian.Tang@freescale.com
On Monday, September 29, 2014 02:05:15 AM Viresh Kumar wrote:
On 24 September 2014 16:45, Rafael J. Wysocki rjw@rjwysocki.net wrote:
On Tuesday, September 02, 2014 09:11:24 AM Viresh Kumar wrote:
'cpu_data' is updated for policy->cpu first and then for all CPUs in policy->cpus. policy->cpus is guaranteed to contain policy->cpu as well and so the first write to 'cpu_data' for policy->cpu is redundant. Remove it.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
I'm not sure about the status here?
Apply only the first patch (1/2) with
Acked-by: Tang Yuantian Yuantian.Tang@freescale.com
Please resend with the ACK.
linaro-kernel@lists.linaro.org
-
Benjamin Herrenschmidt -
Rafael J. Wysocki -
Viresh Kumar -
Yuantian Tang