| Message ID | 20231103131821.1176294-1-vincent.guittot@linaro.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Rework interface between scheduler and schedutil governor | expand |
On Fri, Nov 3, 2023 at 2:18 PM Vincent Guittot <vincent.guittot@linaro.org> wrote: > > Following the discussion with Qais [1] about how to handle uclamp > requirements and after syncing with him, we agreed that I should move > forward on the patchset to rework the interface between scheduler and > schedutil governor to provide more information to the latter. Scheduler > (and EAS in particular) doesn't need anymore to guess estimate which > headroom the governor wants to apply and will directly ask for the target > freq. Then the governor directly gets the actual utilization and new > minimum and maximum boundaries to select this target frequency and > doesn't have to deal anymore with scheduler internals like uclamp when > including iowait boost. > > [1] https://lore.kernel.org/lkml/CAKfTPtA5JqNCauG-rP3wGfq+p8EEVx9Tvwj6ksM3SYCwRmfCTg@mail.gmail.com/ > > Changes since v2: > - remove useless target variable > > Changes since v1: > - fix a bug (always set max even when returning early) > - fix typos > > Vincent Guittot (2): > sched/schedutil: Rework performance estimation > sched/schedutil: Rework iowait boost > > include/linux/energy_model.h | 1 - > kernel/sched/core.c | 82 ++++++++++++------------------- > kernel/sched/cpufreq_schedutil.c | 69 ++++++++++++++++---------- > kernel/sched/fair.c | 22 +++++++-- > kernel/sched/sched.h | 84 +++----------------------------- > 5 files changed, 100 insertions(+), 158 deletions(-) > > -- For the schedutil changes in the series: Acked-by: Rafael J. Wysocki <rafael@kernel.org> and I'm assuming this series to be targeted at sched.
On 11/16/23 15:34, Peter Zijlstra wrote: > On Mon, Nov 06, 2023 at 04:05:40PM +0100, Rafael J. Wysocki wrote: > > On Fri, Nov 3, 2023 at 2:18 PM Vincent Guittot > > <vincent.guittot@linaro.org> wrote: > > > > > > Following the discussion with Qais [1] about how to handle uclamp > > > requirements and after syncing with him, we agreed that I should move > > > forward on the patchset to rework the interface between scheduler and > > > schedutil governor to provide more information to the latter. Scheduler > > > (and EAS in particular) doesn't need anymore to guess estimate which > > > headroom the governor wants to apply and will directly ask for the target > > > freq. Then the governor directly gets the actual utilization and new > > > minimum and maximum boundaries to select this target frequency and > > > doesn't have to deal anymore with scheduler internals like uclamp when > > > including iowait boost. Thanks a lot for taking over Vincent and helping with this! And sorry for delayed review, was out travelling between holiday and LPC so haven't caught up with the list properly yet.. Beside the comments on patch 1, it looks good to me. Do we want to generalize the way the interface is called though so that scheduler is not tightly coupled to schedutil? Speaking with Intel folks in LPC, it seemed they rely on firmware to make a lot of decision and if we further generalize how the interface is called (I think we need a new cpufreq wrapper akin to cpufreq_update_util()) to allow governors to hook into it and do their own thing. This could allow them to use uclamp and these min/max perf hints. But I haven't thought this fully through. So something to consider separately anyway to not hold this up unnecessarily. Maybe we do want to keep schedutil tightly integrated and get people to switch to schedutil instead.. > > > > > > [1] https://lore.kernel.org/lkml/CAKfTPtA5JqNCauG-rP3wGfq+p8EEVx9Tvwj6ksM3SYCwRmfCTg@mail.gmail.com/ > > > > > > Changes since v2: > > > - remove useless target variable > > > > > > Changes since v1: > > > - fix a bug (always set max even when returning early) > > > - fix typos > > > > > > Vincent Guittot (2): > > > sched/schedutil: Rework performance estimation > > > sched/schedutil: Rework iowait boost > > > > > > include/linux/energy_model.h | 1 - > > > kernel/sched/core.c | 82 ++++++++++++------------------- > > > kernel/sched/cpufreq_schedutil.c | 69 ++++++++++++++++---------- > > > kernel/sched/fair.c | 22 +++++++-- > > > kernel/sched/sched.h | 84 +++----------------------------- > > > 5 files changed, 100 insertions(+), 158 deletions(-) > > > > > > -- > > > > For the schedutil changes in the series: > > > > Acked-by: Rafael J. Wysocki <rafael@kernel.org> > > > > and I'm assuming this series to be targeted at sched. > > Sure, I'll go queue it. Thanks! Sorry for being late. If this wasn't queued already I think worth waiting to iron out some comments on patch 1 first. Thanks! -- Qais Yousef
On Mon, Nov 06, 2023 at 04:05:40PM +0100, Rafael J. Wysocki wrote: > On Fri, Nov 3, 2023 at 2:18 PM Vincent Guittot > <vincent.guittot@linaro.org> wrote: > > > > Following the discussion with Qais [1] about how to handle uclamp > > requirements and after syncing with him, we agreed that I should move > > forward on the patchset to rework the interface between scheduler and > > schedutil governor to provide more information to the latter. Scheduler > > (and EAS in particular) doesn't need anymore to guess estimate which > > headroom the governor wants to apply and will directly ask for the target > > freq. Then the governor directly gets the actual utilization and new > > minimum and maximum boundaries to select this target frequency and > > doesn't have to deal anymore with scheduler internals like uclamp when > > including iowait boost. > > > > [1] https://lore.kernel.org/lkml/CAKfTPtA5JqNCauG-rP3wGfq+p8EEVx9Tvwj6ksM3SYCwRmfCTg@mail.gmail.com/ > > > > Changes since v2: > > - remove useless target variable > > > > Changes since v1: > > - fix a bug (always set max even when returning early) > > - fix typos > > > > Vincent Guittot (2): > > sched/schedutil: Rework performance estimation > > sched/schedutil: Rework iowait boost > > > > include/linux/energy_model.h | 1 - > > kernel/sched/core.c | 82 ++++++++++++------------------- > > kernel/sched/cpufreq_schedutil.c | 69 ++++++++++++++++---------- > > kernel/sched/fair.c | 22 +++++++-- > > kernel/sched/sched.h | 84 +++----------------------------- > > 5 files changed, 100 insertions(+), 158 deletions(-) > > > > -- > > For the schedutil changes in the series: > > Acked-by: Rafael J. Wysocki <rafael@kernel.org> > > and I'm assuming this series to be targeted at sched. Sure, I'll go queue it. Thanks!