Messages in this thread |  | | | From | "Rafael J. Wysocki" <> | | Subject | Re: [PATCH v4] PM / QoS: add pm_qos_update_request_timeout API | | Date | Wed, 28 Mar 2012 12:25:48 +0200 |
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On Wednesday, March 28, 2012, MyungJoo Ham wrote: > 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.
Can you please give any details, if possible?
Rafael
> >> -- > >> 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); > >> > > > > > >
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