From b8cbe7e82ec8b55d7bbdde66fc69e788fde00dc6 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 3 Nov 2009 14:57:56 +1030 Subject: [CPUFREQ] cpumask: don't put a cpumask on the stack in x86...cpufreq/powernow-k8.c It's still mugging the current process's cpumask, but as comment in 1ff6e97f1d says, it's not a trivial fix. So, at least we can use a cpumask_var_t to do the Wrong Thing the Right Way :) Signed-off-by: Rusty Russell To: cpufreq@vger.kernel.org Cc: Mark Langsdorf Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/powernow-k8.c') diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index 3f12dabeab52..f30d25383940 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1118,7 +1118,7 @@ static int transition_frequency_pstate(struct powernow_k8_data *data, static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsigned relation) { - cpumask_t oldmask; + cpumask_var_t oldmask; struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); u32 checkfid; u32 checkvid; @@ -1131,9 +1131,13 @@ static int powernowk8_target(struct cpufreq_policy *pol, checkfid = data->currfid; checkvid = data->currvid; - /* only run on specific CPU from here on */ - oldmask = current->cpus_allowed; - set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu)); + /* only run on specific CPU from here on. */ + /* This is poor form: use a workqueue or smp_call_function_single */ + if (!alloc_cpumask_var(&oldmask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_copy(oldmask, tsk_cpumask(current)); + set_cpus_allowed_ptr(current, cpumask_of(pol->cpu)); if (smp_processor_id() != pol->cpu) { printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu); @@ -1193,7 +1197,8 @@ static int powernowk8_target(struct cpufreq_policy *pol, ret = 0; err_out: - set_cpus_allowed_ptr(current, &oldmask); + set_cpus_allowed_ptr(current, oldmask); + free_cpumask_var(oldmask); return ret; } -- cgit v1.2.1 From e2f74f355e9e2914483db10c05d70e69e0b7ae04 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Thu, 19 Nov 2009 12:31:01 +0100 Subject: [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface This interface is mainly intended (and implemented) for ACPI _PPC BIOS frequency limitations, but other cpufreq drivers can also use it for similar use-cases. Why is this needed: Currently it's not obvious why cpufreq got limited. People see cpufreq/scaling_max_freq reduced, but this could have happened by: - any userspace prog writing to scaling_max_freq - thermal limitations - hardware (_PPC in ACPI case) limitiations Therefore export bios_limit (in kHz) to: - Point the user that it's the BIOS (broken or intended) which limits frequency - Export it as a sysfs interface for userspace progs. While this was a rarely used feature on laptops, there will appear more and more server implemenations providing "Green IT" features like allowing the service processor to limit the frequency. People want to know about HW/BIOS frequency limitations. All ACPI P-state driven cpufreq drivers are covered with this patch: - powernow-k8 - powernow-k7 - acpi-cpufreq Tested with a patched DSDT which limits the first two cores (_PPC returns 1) via _PPC, exposed by bios_limit: # echo 2200000 >cpu2/cpufreq/scaling_max_freq # cat cpu*/cpufreq/scaling_max_freq 2600000 2600000 2200000 2200000 # #scaling_max_freq shows general user/thermal/BIOS limitations # cat cpu*/cpufreq/bios_limit 2600000 2600000 2800000 2800000 # #bios_limit only shows the HW/BIOS limitation CC: Pallipadi Venkatesh CC: Len Brown CC: davej@codemonkey.org.uk CC: linux@dominikbrodowski.net Signed-off-by: Thomas Renninger Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'arch/x86/kernel/cpu/cpufreq/powernow-k8.c') diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index f30d25383940..a9df9441a9a2 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1398,14 +1398,15 @@ static struct freq_attr *powernow_k8_attr[] = { }; static struct cpufreq_driver cpufreq_amd64_driver = { - .verify = powernowk8_verify, - .target = powernowk8_target, - .init = powernowk8_cpu_init, - .exit = __devexit_p(powernowk8_cpu_exit), - .get = powernowk8_get, - .name = "powernow-k8", - .owner = THIS_MODULE, - .attr = powernow_k8_attr, + .verify = powernowk8_verify, + .target = powernowk8_target, + .bios_limit = acpi_processor_get_bios_limit, + .init = powernowk8_cpu_init, + .exit = __devexit_p(powernowk8_cpu_exit), + .get = powernowk8_get, + .name = "powernow-k8", + .owner = THIS_MODULE, + .attr = powernow_k8_attr, }; /* driver entry point for init */ -- cgit v1.2.1 From a4636818f8e0991f32d9528f39cf4f3d6a7d30a3 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 17 Dec 2009 11:43:29 -0600 Subject: cpumask: rename tsk_cpumask to tsk_cpus_allowed Noone uses this wrapper yet, and Ingo asked that it be kept consistent with current task_struct usage. (One user crept in via linux-next: fixed) Signed-off-by: Rusty Russell Cc: Tejun Heo --- arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/cpu/cpufreq/powernow-k8.c') diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index a9df9441a9a2..f125e5c551c0 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1136,7 +1136,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, if (!alloc_cpumask_var(&oldmask, GFP_KERNEL)) return -ENOMEM; - cpumask_copy(oldmask, tsk_cpumask(current)); + cpumask_copy(oldmask, tsk_cpus_allowed(current)); set_cpus_allowed_ptr(current, cpumask_of(pol->cpu)); if (smp_processor_id() != pol->cpu) { -- cgit v1.2.1