Messages in this thread | | | Date | Wed, 28 Mar 2012 10:53:19 +0900 | Subject | Re: [PATCH v4] PM / QoS: add pm_qos_update_request_timeout API | From | MyungJoo Ham <> |
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2012/3/28 Rafael J. Wysocki <rjw@sisk.pl>: > On Tuesday, March 27, 2012, MyungJoo Ham wrote: >> The new API, pm_qos_update_request_timeout() is to provide a timeout >> with pm_qos_update_request. >> >> For example, pm_qos_update_request_timeout(req, 100, 1000), means that >> QoS request on req with value 100 will be active for 1000 jiffies. >> After 1000 jiffies, the QoS request thru req is rolled back to the >> request status when pm_qos_update_request_timeout() was called. If there >> were another pm_qos_update_request(req, x) during the 1000 jiffies, this >> new request with value x will override as this is another request on the >> same req handle. > > Can you please update the above part of the changelog to reflect the > fact that microseconds are the new timeout units?
Sure, I've just sent another.
> >> A new request on the same req handle will always >> override the previous request whether it is the conventional request or >> it is the new timeout request. >> >> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> >> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> >> Acked-by: Mark Gross <markgross@thegnar.org> > > It is kind of too late for the 3.4 merge window, so I'd prefer to keep that > for the v3.5 cycle, unless you urgently need it in v3.4, in which case please > let me know. > > Thanks, > Rafael >
Could you please put it with 3.4 if possible? We want to use this feature with 3.4.
Thanks a lot.
Cheers! MyungJoo.
> >> -- >> Changes from v3 >> - The timeout value is expresses in us (1/1000000 sec), not ms (1/1000 sec). >> Changes from v2 >> - Rebased to avoid merge conflict >> Chages from v1(RFC) >> - The semmantics of timeout changed. A timeout now means that the >> corresponding qos-req object is being cancelled, not rolling back to >> the qos request state at the time of API call. With this changes, >> combined with the conventional update_request API, there exists up to >> only one qos request per qos-req object. >> - The timeout value is expressed in ms (1/1000 sec), not jiffies. >> - Style changes, removing unnecessary changes. >> - Bugfixes regarding pending timeout work. >> --- >> include/linux/pm_qos.h | 4 +++ >> kernel/power/qos.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 54 insertions(+), 0 deletions(-) >> >> diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h >> index c8a541e..18689737 100644 >> --- a/include/linux/pm_qos.h >> +++ b/include/linux/pm_qos.h >> @@ -8,6 +8,7 @@ >> #include <linux/notifier.h> >> #include <linux/miscdevice.h> >> #include <linux/device.h> >> +#include <linux/workqueue.h> >> >> enum { >> PM_QOS_RESERVED = 0, >> @@ -29,6 +30,7 @@ enum { >> struct pm_qos_request { >> struct plist_node node; >> int pm_qos_class; >> + struct delayed_work work; /* for pm_qos_update_request_timeout */ >> }; >> >> struct dev_pm_qos_request { >> @@ -73,6 +75,8 @@ void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, >> s32 value); >> void pm_qos_update_request(struct pm_qos_request *req, >> s32 new_value); >> +void pm_qos_update_request_timeout(struct pm_qos_request *req, >> + s32 new_value, unsigned long timeout_us); >> void pm_qos_remove_request(struct pm_qos_request *req); >> >> int pm_qos_request(int pm_qos_class); >> diff --git a/kernel/power/qos.c b/kernel/power/qos.c >> index d6d6dbd..6a031e6 100644 >> --- a/kernel/power/qos.c >> +++ b/kernel/power/qos.c >> @@ -230,6 +230,21 @@ int pm_qos_request_active(struct pm_qos_request *req) >> EXPORT_SYMBOL_GPL(pm_qos_request_active); >> >> /** >> + * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout >> + * @work: work struct for the delayed work (timeout) >> + * >> + * This cancels the timeout request by falling back to the default at timeout. >> + */ >> +static void pm_qos_work_fn(struct work_struct *work) >> +{ >> + struct pm_qos_request *req = container_of(to_delayed_work(work), >> + struct pm_qos_request, >> + work); >> + >> + pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); >> +} >> + >> +/** >> * pm_qos_add_request - inserts new qos request into the list >> * @req: pointer to a preallocated handle >> * @pm_qos_class: identifies which list of qos request to use >> @@ -253,6 +268,7 @@ void pm_qos_add_request(struct pm_qos_request *req, >> return; >> } >> req->pm_qos_class = pm_qos_class; >> + INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); >> pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, >> &req->node, PM_QOS_ADD_REQ, value); >> } >> @@ -279,6 +295,9 @@ void pm_qos_update_request(struct pm_qos_request *req, >> return; >> } >> >> + if (delayed_work_pending(&req->work)) >> + cancel_delayed_work_sync(&req->work); >> + >> if (new_value != req->node.prio) >> pm_qos_update_target( >> pm_qos_array[req->pm_qos_class]->constraints, >> @@ -287,6 +306,34 @@ void pm_qos_update_request(struct pm_qos_request *req, >> EXPORT_SYMBOL_GPL(pm_qos_update_request); >> >> /** >> + * pm_qos_update_request_timeout - modifies an existing qos request temporarily. >> + * @req : handle to list element holding a pm_qos request to use >> + * @new_value: defines the temporal qos request >> + * @timeout_us: the effective duration of this qos request in usecs. >> + * >> + * After timeout_us, this qos request is cancelled automatically. >> + */ >> +void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, >> + unsigned long timeout_us) >> +{ >> + if (!req) >> + return; >> + if (WARN(!pm_qos_request_active(req), >> + "%s called for unknown object.", __func__)) >> + return; >> + >> + if (delayed_work_pending(&req->work)) >> + cancel_delayed_work_sync(&req->work); >> + >> + if (new_value != req->node.prio) >> + pm_qos_update_target( >> + pm_qos_array[req->pm_qos_class]->constraints, >> + &req->node, PM_QOS_UPDATE_REQ, new_value); >> + >> + schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); >> +} >> + >> +/** >> * pm_qos_remove_request - modifies an existing qos request >> * @req: handle to request list element >> * >> @@ -305,6 +352,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) >> return; >> } >> >> + if (delayed_work_pending(&req->work)) >> + cancel_delayed_work_sync(&req->work); >> + >> pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, >> &req->node, PM_QOS_REMOVE_REQ, >> PM_QOS_DEFAULT_VALUE); >> >
-- MyungJoo Ham, Ph.D. Mobile Software Platform Lab, DMC Business, Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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