| Message ID | 20240508034352.18414-3-ricardo.neri-calderon@linux.intel.com (mailing list archive) |
|---|---|
| State | In Next |
| Delegated to: | Rafael Wysocki |
| Headers | show |
| Series | thermal: intel: hfi: Update thermal netlink parameters | expand |
On Tue, 2024-05-07 at 20:43 -0700, Ricardo Neri wrote: > The delay between an HFI interrupt and its corresponding thermal > netlink > event has so far been hard-coded to CONFIG_HZ jiffies (1 second). > This > delay is too long for hardware that generates updates every tens of > milliseconds. > > The HFI driver uses a delayed workqueue to send thermal netlink > events. No > subsequent events will be sent if there is pending work. > > As a result, much of the information of consecutive hardware updates > will > be lost if the workqueue delay is too long. User space entities may > act on > obsolete data. If the delay is too short, multiple events may > overwhelm > listeners. > > Set the delay to 100ms to strike a balance between too many and too > few > events. Use milliseconds instead of jiffies to improve readability. > > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> Acked-by: Zhang Rui <rui.zhang@intel.com> -rui > --- > Cc: Len Brown <len.brown@intel.com> > Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Cc: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> > Cc: Zhang Rui <rui.zhang@intel.com> > Cc: linux-pm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > Changes since v1: > * Dropped the debugfs interface. Instead, updated the delay from 1s > to > 100ms. > --- > drivers/thermal/intel/intel_hfi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/intel/intel_hfi.c > b/drivers/thermal/intel/intel_hfi.c > index e2b82d71ab6b..d82b8788b0f8 100644 > --- a/drivers/thermal/intel/intel_hfi.c > +++ b/drivers/thermal/intel/intel_hfi.c > @@ -166,7 +166,7 @@ static struct hfi_features hfi_features; > static DEFINE_MUTEX(hfi_instance_lock); > > static struct workqueue_struct *hfi_updates_wq; > -#define HFI_UPDATE_DELAY HZ > +#define HFI_UPDATE_DELAY_MS 100 > #define HFI_MAX_THERM_NOTIFY_COUNT 16 > > static void get_hfi_caps(struct hfi_instance *hfi_instance, > @@ -322,7 +322,7 @@ void intel_hfi_process_event(__u64 > pkg_therm_status_msr_val) > raw_spin_unlock(&hfi_instance->event_lock); > > queue_delayed_work(hfi_updates_wq, &hfi_instance- > >update_work, > - HFI_UPDATE_DELAY); > + msecs_to_jiffies(HFI_UPDATE_DELAY_MS)); > } > > static void init_hfi_cpu_index(struct hfi_cpu_info *info)
diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c index e2b82d71ab6b..d82b8788b0f8 100644 --- a/drivers/thermal/intel/intel_hfi.c +++ b/drivers/thermal/intel/intel_hfi.c @@ -166,7 +166,7 @@ static struct hfi_features hfi_features; static DEFINE_MUTEX(hfi_instance_lock); static struct workqueue_struct *hfi_updates_wq; -#define HFI_UPDATE_DELAY HZ +#define HFI_UPDATE_DELAY_MS 100 #define HFI_MAX_THERM_NOTIFY_COUNT 16 static void get_hfi_caps(struct hfi_instance *hfi_instance, @@ -322,7 +322,7 @@ void intel_hfi_process_event(__u64 pkg_therm_status_msr_val) raw_spin_unlock(&hfi_instance->event_lock); queue_delayed_work(hfi_updates_wq, &hfi_instance->update_work, - HFI_UPDATE_DELAY); + msecs_to_jiffies(HFI_UPDATE_DELAY_MS)); } static void init_hfi_cpu_index(struct hfi_cpu_info *info)
The delay between an HFI interrupt and its corresponding thermal netlink event has so far been hard-coded to CONFIG_HZ jiffies (1 second). This delay is too long for hardware that generates updates every tens of milliseconds. The HFI driver uses a delayed workqueue to send thermal netlink events. No subsequent events will be sent if there is pending work. As a result, much of the information of consecutive hardware updates will be lost if the workqueue delay is too long. User space entities may act on obsolete data. If the delay is too short, multiple events may overwhelm listeners. Set the delay to 100ms to strike a balance between too many and too few events. Use milliseconds instead of jiffies to improve readability. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- Cc: Len Brown <len.brown@intel.com> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Changes since v1: * Dropped the debugfs interface. Instead, updated the delay from 1s to 100ms. --- drivers/thermal/intel/intel_hfi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)