| Message ID | 1407945689-18494-3-git-send-email-lina.iyer@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi Lina, some minor nits, On Wed, Aug 13, 2014 at 05:01:27PM +0100, Lina Iyer wrote: > QoS request can be better optimized if the request can be set only for > the required cpus and not all cpus. This helps save power on other > cores, while still gauranteeing the quality of service on the desired guaranteeing > cores. > > Add a new enumeration to specify the PM QoS request type. The enums help > specify what is the intended target cpu of the request. > > Enhance the QoS constraints data structures to support target value for > each core. Requests specify if the QoS is applicable to all cores > (default) or to a selective subset of the cores or to a core(s). > > Idle and interested drivers can request a PM QoS value for a constraint > across all cpus, or a specific cpu or a set of cpus. Separate APIs have > been added to request for individual cpu or a cpumask. The default > behaviour of PM QoS is maintained i.e, requests that do not specify a > type of the request will continue to be effected on all cores. > > The userspace sysfs interface does not support setting cpumask of a PM > QoS request. > > Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > --- > Documentation/power/pm_qos_interface.txt | 16 +++++ > include/linux/pm_qos.h | 13 ++++ > kernel/power/qos.c | 102 +++++++++++++++++++++++++++++++ > 3 files changed, 131 insertions(+) > [...] > diff --git a/kernel/power/qos.c b/kernel/power/qos.c > index d0b9c0f..27f84a2 100644 > --- a/kernel/power/qos.c > +++ b/kernel/power/qos.c > @@ -65,6 +65,8 @@ static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); > static struct pm_qos_constraints cpu_dma_constraints = { > .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), > .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, > + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = > + PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE }, > .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, > .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, > .type = PM_QOS_MIN, > @@ -79,6 +81,8 @@ static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); > static struct pm_qos_constraints network_lat_constraints = { > .list = PLIST_HEAD_INIT(network_lat_constraints.list), > .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, > + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = > + PM_QOS_NETWORK_LAT_DEFAULT_VALUE }, > .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, > .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, > .type = PM_QOS_MIN, > @@ -94,6 +98,8 @@ static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); > static struct pm_qos_constraints network_tput_constraints = { > .list = PLIST_HEAD_INIT(network_tput_constraints.list), > .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, > + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = > + PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE }, > .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, > .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, > .type = PM_QOS_MAX, > @@ -157,6 +163,43 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) > c->target_value = value; > } > > +static inline void pm_qos_set_value_for_cpus(struct pm_qos_constraints *c) > +{ > + struct pm_qos_request *req = NULL; > + int cpu; > + s32 *qos_val; > + > + qos_val = kcalloc(NR_CPUS, sizeof(*qos_val), GFP_KERNEL); > + if (!qos_val) { > + WARN("%s: No memory for PM QoS\n", __func__); > + return; > + } > + > + for_each_possible_cpu(cpu) > + qos_val[cpu] = c->default_value; > + > + plist_for_each_entry(req, &c->list, node) { > + for_each_cpu(cpu, &req->cpus_affine) { > + switch (c->type) { > + case PM_QOS_MIN: > + if (qos_val[cpu] > req->node.prio) > + qos_val[cpu] = req->node.prio; > + break; > + case PM_QOS_MAX: > + if (req->node.prio > qos_val[cpu]) > + qos_val[cpu] = req->node.prio; > + break; > + default: > + BUG(); > + break; > + } > + } > + } > + > + for_each_possible_cpu(cpu) > + c->target_per_cpu[cpu] = qos_val[cpu]; > +} > + > /** > * pm_qos_update_target - manages the constraints list and calls the notifiers > * if needed > @@ -206,6 +249,7 @@ int pm_qos_update_target(struct pm_qos_constraints *c, > > curr_value = pm_qos_get_value(c); > pm_qos_set_value(c, curr_value); > + pm_qos_set_value_for_cpus(c); > > spin_unlock_irqrestore(&pm_qos_lock, flags); > > @@ -298,6 +342,44 @@ int pm_qos_request(int pm_qos_class) > } > EXPORT_SYMBOL_GPL(pm_qos_request); > > +int pm_qos_request_for_cpu(int pm_qos_class, int cpu) > +{ > + return pm_qos_array[pm_qos_class]->constraints->target_per_cpu[cpu]; > +} > +EXPORT_SYMBOL(pm_qos_request_for_cpu); > + > +int pm_qos_request_for_cpumask(int pm_qos_class, struct cpumask *mask) > +{ > + unsigned long irqflags; > + int cpu; > + struct pm_qos_constraints *c = NULL; > + int val; > + > + spin_lock_irqsave(&pm_qos_lock, irqflags); > + c = pm_qos_array[pm_qos_class]->constraints; > + val = c->default_value; > + > + for_each_cpu(cpu, mask) { > + switch (c->type) { > + case PM_QOS_MIN: > + if (c->target_per_cpu[cpu] < val) > + val = c->target_per_cpu[cpu]; > + break; > + case PM_QOS_MAX: > + if (c->target_per_cpu[cpu] > val) > + val = c->target_per_cpu[cpu]; > + break; > + default: > + BUG(); > + break; > + } > + } > + spin_unlock_irqrestore(&pm_qos_lock, irqflags); > + > + return val; > +} > +EXPORT_SYMBOL(pm_qos_request_for_cpumask); > + > int pm_qos_request_active(struct pm_qos_request *req) > { > return req->pm_qos_class != 0; > @@ -353,6 +435,24 @@ void pm_qos_add_request(struct pm_qos_request *req, > WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); > return; > } > + > + switch (req->type) { > + case PM_QOS_REQ_AFFINE_CORES: > + if (cpumask_empty(&req->cpus_affine)) { > + req->type = PM_QOS_REQ_ALL_CORES; > + cpumask_setall(&req->cpus_affine); > + WARN(1, KERN_ERR "Affine cores not set for request with affinity flag\n"); > + } > + break; > + > + default: > + WARN(1, KERN_ERR "Unknown request type %d\n", req->type); > + /* fall through */ > + case PM_QOS_REQ_ALL_CORES: > + cpumask_setall(&req->cpus_affine); > + break; > + } > + > req->pm_qos_class = pm_qos_class; > INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); > trace_pm_qos_add_request(pm_qos_class, value); > @@ -426,6 +526,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, > */ > void pm_qos_remove_request(struct pm_qos_request *req) > { > + Unnecessary newline added. > if (!req) /*guard against callers passing in null */ > return; > /* silent return to keep pcm code cleaner */ > @@ -441,6 +542,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) > pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, > req, PM_QOS_REMOVE_REQ, > PM_QOS_DEFAULT_VALUE); > + ditto. Cheers, Javi > memset(req, 0, sizeof(*req)); > } > EXPORT_SYMBOL_GPL(pm_qos_remove_request); > -- > 1.9.1 > > -- > 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 > -- 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 Fri, Aug 15, 2014 at 01:37:32PM +0100, Javi Merino wrote: >Hi Lina, some minor nits, > >On Wed, Aug 13, 2014 at 05:01:27PM +0100, Lina Iyer wrote: >> QoS request can be better optimized if the request can be set only for >> the required cpus and not all cpus. This helps save power on other >> cores, while still gauranteeing the quality of service on the desired > > guaranteeing > I never get that right :[ Will take care of it. >> cores. >> >> Add a new enumeration to specify the PM QoS request type. The enums help >> specify what is the intended target cpu of the request. >> >> Enhance the QoS constraints data structures to support target value for >> each core. Requests specify if the QoS is applicable to all cores >> (default) or to a selective subset of the cores or to a core(s). >> >> Idle and interested drivers can request a PM QoS value for a constraint >> across all cpus, or a specific cpu or a set of cpus. Separate APIs have >> been added to request for individual cpu or a cpumask. The default >> behaviour of PM QoS is maintained i.e, requests that do not specify a >> type of the request will continue to be effected on all cores. >> >> The userspace sysfs interface does not support setting cpumask of a PM >> QoS request. >> >> Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> >> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> >> --- >> Documentation/power/pm_qos_interface.txt | 16 +++++ >> include/linux/pm_qos.h | 13 ++++ >> kernel/power/qos.c | 102 +++++++++++++++++++++++++++++++ >> 3 files changed, 131 insertions(+) >> >[...] >> diff --git a/kernel/power/qos.c b/kernel/power/qos.c >> index d0b9c0f..27f84a2 100644 >> --- a/kernel/power/qos.c >> +++ b/kernel/power/qos.c >> @@ -65,6 +65,8 @@ static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); >> static struct pm_qos_constraints cpu_dma_constraints = { >> .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), >> .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, >> + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = >> + PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE }, >> .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, >> .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, >> .type = PM_QOS_MIN, >> @@ -79,6 +81,8 @@ static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); >> static struct pm_qos_constraints network_lat_constraints = { >> .list = PLIST_HEAD_INIT(network_lat_constraints.list), >> .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, >> + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = >> + PM_QOS_NETWORK_LAT_DEFAULT_VALUE }, >> .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, >> .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, >> .type = PM_QOS_MIN, >> @@ -94,6 +98,8 @@ static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); >> static struct pm_qos_constraints network_tput_constraints = { >> .list = PLIST_HEAD_INIT(network_tput_constraints.list), >> .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, >> + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = >> + PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE }, >> .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, >> .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, >> .type = PM_QOS_MAX, >> @@ -157,6 +163,43 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) >> c->target_value = value; >> } >> >> +static inline void pm_qos_set_value_for_cpus(struct pm_qos_constraints *c) >> +{ >> + struct pm_qos_request *req = NULL; >> + int cpu; >> + s32 *qos_val; >> + >> + qos_val = kcalloc(NR_CPUS, sizeof(*qos_val), GFP_KERNEL); >> + if (!qos_val) { >> + WARN("%s: No memory for PM QoS\n", __func__); >> + return; >> + } >> + >> + for_each_possible_cpu(cpu) >> + qos_val[cpu] = c->default_value; >> + >> + plist_for_each_entry(req, &c->list, node) { >> + for_each_cpu(cpu, &req->cpus_affine) { >> + switch (c->type) { >> + case PM_QOS_MIN: >> + if (qos_val[cpu] > req->node.prio) >> + qos_val[cpu] = req->node.prio; >> + break; >> + case PM_QOS_MAX: >> + if (req->node.prio > qos_val[cpu]) >> + qos_val[cpu] = req->node.prio; >> + break; >> + default: >> + BUG(); >> + break; >> + } >> + } >> + } >> + >> + for_each_possible_cpu(cpu) >> + c->target_per_cpu[cpu] = qos_val[cpu]; >> +} >> + >> /** >> * pm_qos_update_target - manages the constraints list and calls the notifiers >> * if needed >> @@ -206,6 +249,7 @@ int pm_qos_update_target(struct pm_qos_constraints *c, >> >> curr_value = pm_qos_get_value(c); >> pm_qos_set_value(c, curr_value); >> + pm_qos_set_value_for_cpus(c); >> >> spin_unlock_irqrestore(&pm_qos_lock, flags); >> >> @@ -298,6 +342,44 @@ int pm_qos_request(int pm_qos_class) >> } >> EXPORT_SYMBOL_GPL(pm_qos_request); >> >> +int pm_qos_request_for_cpu(int pm_qos_class, int cpu) >> +{ >> + return pm_qos_array[pm_qos_class]->constraints->target_per_cpu[cpu]; >> +} >> +EXPORT_SYMBOL(pm_qos_request_for_cpu); >> + >> +int pm_qos_request_for_cpumask(int pm_qos_class, struct cpumask *mask) >> +{ >> + unsigned long irqflags; >> + int cpu; >> + struct pm_qos_constraints *c = NULL; >> + int val; >> + >> + spin_lock_irqsave(&pm_qos_lock, irqflags); >> + c = pm_qos_array[pm_qos_class]->constraints; >> + val = c->default_value; >> + >> + for_each_cpu(cpu, mask) { >> + switch (c->type) { >> + case PM_QOS_MIN: >> + if (c->target_per_cpu[cpu] < val) >> + val = c->target_per_cpu[cpu]; >> + break; >> + case PM_QOS_MAX: >> + if (c->target_per_cpu[cpu] > val) >> + val = c->target_per_cpu[cpu]; >> + break; >> + default: >> + BUG(); >> + break; >> + } >> + } >> + spin_unlock_irqrestore(&pm_qos_lock, irqflags); >> + >> + return val; >> +} >> +EXPORT_SYMBOL(pm_qos_request_for_cpumask); >> + >> int pm_qos_request_active(struct pm_qos_request *req) >> { >> return req->pm_qos_class != 0; >> @@ -353,6 +435,24 @@ void pm_qos_add_request(struct pm_qos_request *req, >> WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); >> return; >> } >> + >> + switch (req->type) { >> + case PM_QOS_REQ_AFFINE_CORES: >> + if (cpumask_empty(&req->cpus_affine)) { >> + req->type = PM_QOS_REQ_ALL_CORES; >> + cpumask_setall(&req->cpus_affine); >> + WARN(1, KERN_ERR "Affine cores not set for request with affinity flag\n"); >> + } >> + break; >> + >> + default: >> + WARN(1, KERN_ERR "Unknown request type %d\n", req->type); >> + /* fall through */ >> + case PM_QOS_REQ_ALL_CORES: >> + cpumask_setall(&req->cpus_affine); >> + break; >> + } >> + >> req->pm_qos_class = pm_qos_class; >> INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); >> trace_pm_qos_add_request(pm_qos_class, value); >> @@ -426,6 +526,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, >> */ >> void pm_qos_remove_request(struct pm_qos_request *req) >> { >> + > >Unnecessary newline added. > >> if (!req) /*guard against callers passing in null */ >> return; >> /* silent return to keep pcm code cleaner */ >> @@ -441,6 +542,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) >> pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, >> req, PM_QOS_REMOVE_REQ, >> PM_QOS_DEFAULT_VALUE); >> + > >ditto. Cheers, >Javi > >> memset(req, 0, sizeof(*req)); >> } >> EXPORT_SYMBOL_GPL(pm_qos_remove_request); >> -- >> 1.9.1 >> >> -- >> 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 >> > -- 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
Hi Lina, Lina Iyer <lina.iyer@linaro.org> writes: > QoS request can be better optimized if the request can be set only for > the required cpus and not all cpus. This helps save power on other > cores, while still gauranteeing the quality of service on the desired > cores. > > Add a new enumeration to specify the PM QoS request type. The enums help > specify what is the intended target cpu of the request. > > Enhance the QoS constraints data structures to support target value for > each core. Requests specify if the QoS is applicable to all cores > (default) or to a selective subset of the cores or to a core(s). > > Idle and interested drivers can request a PM QoS value for a constraint > across all cpus, or a specific cpu or a set of cpus. Separate APIs have > been added to request for individual cpu or a cpumask. The default > behaviour of PM QoS is maintained i.e, requests that do not specify a > type of the request will continue to be effected on all cores. > > The userspace sysfs interface does not support setting cpumask of a PM > QoS request. > > Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> I agree this is a needed feature. I didn't study it in detail yet, but after a quick glance, it looks like a good approach. However, I did start to wonder how this will behave in the context of the hotplug. For example, what if a constraint is setup with a cpumask, then one of those CPUs is hotplugged away. Kevin -- 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 Mon, Aug 18, 2014 at 04:55:41PM -0700, Kevin Hilman wrote: >Hi Lina, > >Lina Iyer <lina.iyer@linaro.org> writes: > >> QoS request can be better optimized if the request can be set only for >> the required cpus and not all cpus. This helps save power on other >> cores, while still gauranteeing the quality of service on the desired >> cores. >> >> Add a new enumeration to specify the PM QoS request type. The enums help >> specify what is the intended target cpu of the request. >> >> Enhance the QoS constraints data structures to support target value for >> each core. Requests specify if the QoS is applicable to all cores >> (default) or to a selective subset of the cores or to a core(s). >> >> Idle and interested drivers can request a PM QoS value for a constraint >> across all cpus, or a specific cpu or a set of cpus. Separate APIs have >> been added to request for individual cpu or a cpumask. The default >> behaviour of PM QoS is maintained i.e, requests that do not specify a >> type of the request will continue to be effected on all cores. >> >> The userspace sysfs interface does not support setting cpumask of a PM >> QoS request. >> >> Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> >> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > >I agree this is a needed feature. I didn't study it in detail yet, but >after a quick glance, it looks like a good approach. > >However, I did start to wonder how this will behave in the context of >the hotplug. For example, what if a constraint is setup with a cpumask, >then one of those CPUs is hotplugged away. > Thanks for bringing it up. I forgot to mention this in the series, but well, it can be addressed. When a core is hotplugged, the IRQ migrates to the next online in the smp_affinity. The QoS code would work in the hotplug case as well, with a simple change. The current code does not send affinity_notifications correctly because of a direct call to irq_chip->irq_set_affinity() instead of calling the generic irq affinity api. This is the simple change that needs to be made. I will submit a patch for that. In arm64/kernel/irq.c - c = irq_data_get_irq_chip(d); - if (!c->irq_set_affinity) - pr_debug("IRQ%u: unable to set affinity\n", d->irq); - else if (c->irq_set_affinity(d, affinity, true) == IRQ_SET_MASK_OK && ret) - cpumask_copy(d->affinity, affinity); - - return ret; + return __irq_set_affinity_locked(d, affinity) == 0; >Kevin -- 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
Lina Iyer <lina.iyer@linaro.org> writes: > QoS request can be better optimized if the request can be set only for > the required cpus and not all cpus. This helps save power on other > cores, while still gauranteeing the quality of service on the desired > cores. > > Add a new enumeration to specify the PM QoS request type. The enums help > specify what is the intended target cpu of the request. > > Enhance the QoS constraints data structures to support target value for > each core. Requests specify if the QoS is applicable to all cores > (default) or to a selective subset of the cores or to a core(s). > > Idle and interested drivers can request a PM QoS value for a constraint > across all cpus, or a specific cpu or a set of cpus. Separate APIs have > been added to request for individual cpu or a cpumask. The default > behaviour of PM QoS is maintained i.e, requests that do not specify a > type of the request will continue to be effected on all cores. > > The userspace sysfs interface does not support setting cpumask of a PM > QoS request. > > Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> I'm curious if you looked at using the per-device QoS API for this instead of expending the system-wide API. IOW, from a per-device QoS POV, a CPU is no different than any other device, and since we already have the per-device QoS API, I wondered if that might be a better choice to implment this per-CPU feature. Kevin -- 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 Wed, Aug 27, 2014 at 11:01:40AM -0700, Kevin Hilman wrote: >Lina Iyer <lina.iyer@linaro.org> writes: > >> QoS request can be better optimized if the request can be set only for >> the required cpus and not all cpus. This helps save power on other >> cores, while still gauranteeing the quality of service on the desired >> cores. >> >> Add a new enumeration to specify the PM QoS request type. The enums help >> specify what is the intended target cpu of the request. >> >> Enhance the QoS constraints data structures to support target value for >> each core. Requests specify if the QoS is applicable to all cores >> (default) or to a selective subset of the cores or to a core(s). >> >> Idle and interested drivers can request a PM QoS value for a constraint >> across all cpus, or a specific cpu or a set of cpus. Separate APIs have >> been added to request for individual cpu or a cpumask. The default >> behaviour of PM QoS is maintained i.e, requests that do not specify a >> type of the request will continue to be effected on all cores. >> >> The userspace sysfs interface does not support setting cpumask of a PM >> QoS request. >> >> Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org> >> Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > >I'm curious if you looked at using the per-device QoS API for this >instead of expending the system-wide API. IOW, from a per-device QoS >POV, a CPU is no different than any other device, and since we already >have the per-device QoS API, I wondered if that might be a better choice >to implment this per-CPU feature. > If you mean dev-pm-qos, then yes. I explored using that. The dev-pm-qos is an user of the qos framework and holds an pm-qos object, but not in any other way influences the final value of the QoS constraint other than specify a request on behalf of the device. IMHO, What we want is complementary. When a device specifies a request, we want the request to be directed at a set of cpus and that is a function of the QoS framework, hence addressed by these patches to the QoS framework. >Kevin >-- >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 -- 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/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt index a5da5c7..c129517 100644 --- a/Documentation/power/pm_qos_interface.txt +++ b/Documentation/power/pm_qos_interface.txt @@ -41,6 +41,15 @@ registered notifiers are called only if the target value is now different. Clients of pm_qos need to save the returned handle for future use in other pm_qos API functions. +The handle is a pm_qos_request object. By default the request object sets the +request type to PM_QOS_REQ_ALL_CORES, in which case, the PM QoS request +applies to all cores. However, the driver can also specify a request type to +be either of + PM_QOS_REQ_ALL_CORES, + PM_QOS_REQ_AFFINE_CORES, + +Specify the cpumask when type is set to PM_QOS_REQ_AFFINE_CORES. + void pm_qos_update_request(handle, new_target_value): Will update the list element pointed to by the handle with the new target value and recompute the new aggregated target, calling the notification tree if the @@ -54,6 +63,13 @@ the request. int pm_qos_request(param_class): Returns the aggregated value for a given PM QoS class. +int pm_qos_request_for_cpu(param_class, cpu): +Returns the aggregated value for a given PM QoS class for the specified cpu. + +int pm_qos_request_for_cpumask(param_class, cpumask): +Returns the aggregated value for a given PM QoS class for the specified +cpumask. + int pm_qos_request_active(handle): Returns if the request is still active, i.e. it has not been removed from a PM QoS class constraints list. diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index e1b763d..a3aa5b5 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -9,6 +9,8 @@ #include <linux/miscdevice.h> #include <linux/device.h> #include <linux/workqueue.h> +#include <linux/cpumask.h> +#include <linux/interrupt.h> enum { PM_QOS_RESERVED = 0, @@ -40,7 +42,15 @@ enum pm_qos_flags_status { #define PM_QOS_FLAG_NO_POWER_OFF (1 << 0) #define PM_QOS_FLAG_REMOTE_WAKEUP (1 << 1) +enum pm_qos_req_type { + PM_QOS_REQ_ALL_CORES = 0, + PM_QOS_REQ_AFFINE_CORES, +}; + struct pm_qos_request { + enum pm_qos_req_type type; + struct cpumask cpus_affine; + /* Internal structure members */ struct plist_node node; int pm_qos_class; struct delayed_work work; /* for pm_qos_update_request_timeout */ @@ -80,6 +90,7 @@ enum pm_qos_type { struct pm_qos_constraints { struct plist_head list; s32 target_value; /* Do not change to 64 bit */ + s32 target_per_cpu[NR_CPUS]; s32 default_value; s32 no_constraint_value; enum pm_qos_type type; @@ -127,6 +138,8 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, void pm_qos_remove_request(struct pm_qos_request *req); int pm_qos_request(int pm_qos_class); +int pm_qos_request_for_cpu(int pm_qos_class, int cpu); +int pm_qos_request_for_cpumask(int pm_qos_class, struct cpumask *mask); int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index d0b9c0f..27f84a2 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -65,6 +65,8 @@ static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); static struct pm_qos_constraints cpu_dma_constraints = { .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = + PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE }, .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN, @@ -79,6 +81,8 @@ static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); static struct pm_qos_constraints network_lat_constraints = { .list = PLIST_HEAD_INIT(network_lat_constraints.list), .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = + PM_QOS_NETWORK_LAT_DEFAULT_VALUE }, .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, .no_constraint_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN, @@ -94,6 +98,8 @@ static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); static struct pm_qos_constraints network_tput_constraints = { .list = PLIST_HEAD_INIT(network_tput_constraints.list), .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, + .target_per_cpu = { [0 ... (NR_CPUS - 1)] = + PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE }, .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, .no_constraint_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, .type = PM_QOS_MAX, @@ -157,6 +163,43 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) c->target_value = value; } +static inline void pm_qos_set_value_for_cpus(struct pm_qos_constraints *c) +{ + struct pm_qos_request *req = NULL; + int cpu; + s32 *qos_val; + + qos_val = kcalloc(NR_CPUS, sizeof(*qos_val), GFP_KERNEL); + if (!qos_val) { + WARN("%s: No memory for PM QoS\n", __func__); + return; + } + + for_each_possible_cpu(cpu) + qos_val[cpu] = c->default_value; + + plist_for_each_entry(req, &c->list, node) { + for_each_cpu(cpu, &req->cpus_affine) { + switch (c->type) { + case PM_QOS_MIN: + if (qos_val[cpu] > req->node.prio) + qos_val[cpu] = req->node.prio; + break; + case PM_QOS_MAX: + if (req->node.prio > qos_val[cpu]) + qos_val[cpu] = req->node.prio; + break; + default: + BUG(); + break; + } + } + } + + for_each_possible_cpu(cpu) + c->target_per_cpu[cpu] = qos_val[cpu]; +} + /** * pm_qos_update_target - manages the constraints list and calls the notifiers * if needed @@ -206,6 +249,7 @@ int pm_qos_update_target(struct pm_qos_constraints *c, curr_value = pm_qos_get_value(c); pm_qos_set_value(c, curr_value); + pm_qos_set_value_for_cpus(c); spin_unlock_irqrestore(&pm_qos_lock, flags); @@ -298,6 +342,44 @@ int pm_qos_request(int pm_qos_class) } EXPORT_SYMBOL_GPL(pm_qos_request); +int pm_qos_request_for_cpu(int pm_qos_class, int cpu) +{ + return pm_qos_array[pm_qos_class]->constraints->target_per_cpu[cpu]; +} +EXPORT_SYMBOL(pm_qos_request_for_cpu); + +int pm_qos_request_for_cpumask(int pm_qos_class, struct cpumask *mask) +{ + unsigned long irqflags; + int cpu; + struct pm_qos_constraints *c = NULL; + int val; + + spin_lock_irqsave(&pm_qos_lock, irqflags); + c = pm_qos_array[pm_qos_class]->constraints; + val = c->default_value; + + for_each_cpu(cpu, mask) { + switch (c->type) { + case PM_QOS_MIN: + if (c->target_per_cpu[cpu] < val) + val = c->target_per_cpu[cpu]; + break; + case PM_QOS_MAX: + if (c->target_per_cpu[cpu] > val) + val = c->target_per_cpu[cpu]; + break; + default: + BUG(); + break; + } + } + spin_unlock_irqrestore(&pm_qos_lock, irqflags); + + return val; +} +EXPORT_SYMBOL(pm_qos_request_for_cpumask); + int pm_qos_request_active(struct pm_qos_request *req) { return req->pm_qos_class != 0; @@ -353,6 +435,24 @@ void pm_qos_add_request(struct pm_qos_request *req, WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); return; } + + switch (req->type) { + case PM_QOS_REQ_AFFINE_CORES: + if (cpumask_empty(&req->cpus_affine)) { + req->type = PM_QOS_REQ_ALL_CORES; + cpumask_setall(&req->cpus_affine); + WARN(1, KERN_ERR "Affine cores not set for request with affinity flag\n"); + } + break; + + default: + WARN(1, KERN_ERR "Unknown request type %d\n", req->type); + /* fall through */ + case PM_QOS_REQ_ALL_CORES: + cpumask_setall(&req->cpus_affine); + break; + } + req->pm_qos_class = pm_qos_class; INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); trace_pm_qos_add_request(pm_qos_class, value); @@ -426,6 +526,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, */ void pm_qos_remove_request(struct pm_qos_request *req) { + if (!req) /*guard against callers passing in null */ return; /* silent return to keep pcm code cleaner */ @@ -441,6 +542,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_qos_remove_request);