| Message ID | 1356141435-17340-12-git-send-email-tj@kernel.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Friday, December 21, 2012 05:57:01 PM Tejun Heo wrote: > There's no need to test whether a (delayed) work item in pending > before queueing, flushing or cancelling it. Most uses are unnecessary > and quite a few of them are buggy. Can you please say why they are buggy? > Remove unnecessary pending tests from pm autosleep and qos. Only > compile tested. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: "Rafael J. Wysocki" <rjw@sisk.pl> > Cc: linux-pm@vger.kernel.org > --- > Please let me know how this patch should be routed. I can take it > through the workqueue tree if necessary. I can take it. I will send a pull request with fixes later in the cycle (maybe even before -rc2). Thanks, Rafael > kernel/power/autosleep.c | 2 +- > kernel/power/qos.c | 9 +++------ > 2 files changed, 4 insertions(+), 7 deletions(-) > > diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c > index ca304046..c6422ff 100644 > --- a/kernel/power/autosleep.c > +++ b/kernel/power/autosleep.c > @@ -66,7 +66,7 @@ static DECLARE_WORK(suspend_work, try_to_suspend); > > void queue_up_suspend_work(void) > { > - if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON) > + if (autosleep_state > PM_SUSPEND_ON) > queue_work(autosleep_wq, &suspend_work); > } > > diff --git a/kernel/power/qos.c b/kernel/power/qos.c > index 9322ff7..587ddde 100644 > --- a/kernel/power/qos.c > +++ b/kernel/power/qos.c > @@ -359,8 +359,7 @@ void pm_qos_update_request(struct pm_qos_request *req, > return; > } > > - if (delayed_work_pending(&req->work)) > - cancel_delayed_work_sync(&req->work); > + cancel_delayed_work_sync(&req->work); > > if (new_value != req->node.prio) > pm_qos_update_target( > @@ -386,8 +385,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, > "%s called for unknown object.", __func__)) > return; > > - if (delayed_work_pending(&req->work)) > - cancel_delayed_work_sync(&req->work); > + cancel_delayed_work_sync(&req->work); > > if (new_value != req->node.prio) > pm_qos_update_target( > @@ -416,8 +414,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) > return; > } > > - if (delayed_work_pending(&req->work)) > - cancel_delayed_work_sync(&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, >
Hello, Rafael. On Sat, Dec 22, 2012 at 12:53:29PM +0100, Rafael J. Wysocki wrote: > On Friday, December 21, 2012 05:57:01 PM Tejun Heo wrote: > > There's no need to test whether a (delayed) work item in pending > > before queueing, flushing or cancelling it. Most uses are unnecessary > > and quite a few of them are buggy. > > Can you please say why they are buggy? Usually one of the following two reasons. * The user gets confused and fails to handle !PENDING && currently executing properly. * work_pending() doesn't have any memory barrier and the caller assumes work_pending() is somehow properly synchronized by itself. Thanks.
diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c index ca304046..c6422ff 100644 --- a/kernel/power/autosleep.c +++ b/kernel/power/autosleep.c @@ -66,7 +66,7 @@ static DECLARE_WORK(suspend_work, try_to_suspend); void queue_up_suspend_work(void) { - if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON) + if (autosleep_state > PM_SUSPEND_ON) queue_work(autosleep_wq, &suspend_work); } diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 9322ff7..587ddde 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -359,8 +359,7 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&req->work); + cancel_delayed_work_sync(&req->work); if (new_value != req->node.prio) pm_qos_update_target( @@ -386,8 +385,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, "%s called for unknown object.", __func__)) return; - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&req->work); + cancel_delayed_work_sync(&req->work); if (new_value != req->node.prio) pm_qos_update_target( @@ -416,8 +414,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - if (delayed_work_pending(&req->work)) - cancel_delayed_work_sync(&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,
There's no need to test whether a (delayed) work item in pending before queueing, flushing or cancelling it. Most uses are unnecessary and quite a few of them are buggy. Remove unnecessary pending tests from pm autosleep and qos. Only compile tested. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: linux-pm@vger.kernel.org --- Please let me know how this patch should be routed. I can take it through the workqueue tree if necessary. Thanks. kernel/power/autosleep.c | 2 +- kernel/power/qos.c | 9 +++------ 2 files changed, 4 insertions(+), 7 deletions(-)