| Message ID | 20230205025902.2899734-1-srinivas.pandruvada@linux.intel.com |
|---|---|
| Headers | show |
| Series | intel_powerclamp: New module parameter | expand |
On Mon, Feb 06, 2023 at 02:02:28AM -0800, srinivas pandruvada wrote: > On Mon, 2023-02-06 at 08:05 +0000, Zhang, Rui wrote: > > On Sun, 2023-02-05 at 18:45 -0800, srinivas pandruvada wrote: > > > Hi Rui, > > > > > > On Sun, 2023-02-05 at 15:57 +0000, Zhang, Rui wrote: > > > > Hi, Srinivas, > > > > > > > > First of all, the previous build error is gone. > > > > > > > > Second, I found something strange, which may be related with the > > > > scheduler asym-packing, so CC Ricardo. > > > > > > > I thought you disable ITMT before idle injection and reenebale > > > after > > > removal. > > > > No. > > > > I can reproduce this by playing with raw intel_powerclamp sysfs knobs > > and ITMT enabled. > > > > This issue is happening even if ITMT disabled. If the module mask is > composed of P-cores it works or even on servers as expected. > Also if you offline all P-cores then select mask among E-cores, it is > working. Somehow P-core influences E-cores. > > Since this patch is module mask related, that is functioning correctly. > We have to debug this interaction with P and E cores separately. Currently, when doing asym_packing, ECores will only pull tasks from a PCore only if both SMT siblings are busy. It will only pull from the lower-priority sibling. These patches [1] let ECores pull from either sibling, if both are busy. I presume that by injecting idle, the scheduler thinks that the CPU is idle (i.e., idle_cpu() returns true) and it will not do asym_packing from lower-priority CPUs. However, in your experiment you have 16 threads. If a Pcore is overloaded, an ECore should be able to help. [1]. https://lore.kernel.org/lkml/20230207045838.11243-1-ricardo.neri-calderon@linux.intel.com/
On Tue, 2023-02-07 at 05:42 -0800, Ricardo Neri wrote: > On Mon, Feb 06, 2023 at 02:02:28AM -0800, srinivas pandruvada wrote: > > On Mon, 2023-02-06 at 08:05 +0000, Zhang, Rui wrote: > > > On Sun, 2023-02-05 at 18:45 -0800, srinivas pandruvada wrote: > > > > Hi Rui, > > > > > > > > On Sun, 2023-02-05 at 15:57 +0000, Zhang, Rui wrote: > > > > > Hi, Srinivas, > > > > > > > > > > First of all, the previous build error is gone. > > > > > > > > > > Second, I found something strange, which may be related with > > > > > the > > > > > scheduler asym-packing, so CC Ricardo. > > > > > > > > > I thought you disable ITMT before idle injection and reenebale > > > > after > > > > removal. > > > > > > No. > > > > > > I can reproduce this by playing with raw intel_powerclamp sysfs > > > knobs > > > and ITMT enabled. > > > > > > > This issue is happening even if ITMT disabled. If the module mask > > is > > composed of P-cores it works or even on servers as expected. > > Also if you offline all P-cores then select mask among E-cores, it > > is > > working. Somehow P-core influences E-cores. > > > > Since this patch is module mask related, that is functioning > > correctly. > > We have to debug this interaction with P and E cores separately. > > Currently, when doing asym_packing, ECores will only pull tasks from > a > PCore only if both SMT siblings are busy. It will only pull from the > lower-priority sibling. These patches [1] let ECores pull from either > sibling, if both are busy. > > I presume that by injecting idle, the scheduler thinks that the CPU > is > idle (i.e., idle_cpu() returns true) and it will not do asym_packing > from > lower-priority CPUs. > > However, in your experiment you have 16 threads. If a Pcore is > overloaded, > an ECore should be able to help. This issue happens with or without ITMT and also without any idle injection active. Thanks, Srinivas > > [1]. > https://lore.kernel.org/lkml/20230207045838.11243-1-ricardo.neri-calderon@linux.intel.com/ >
Split from the series for powerclamp user of powercap idle-inject. v2 - Build warnings reported by Rui - Moved the powerclamp documentation to admin guide folder - Commit log updated as suggested by Rafael and other code suggestion Srinivas Pandruvada (2): Documentation:admin-guide: Move intel_powerclamp documentation thermal/drivers/intel_powerclamp: Add two module parameters Documentation/admin-guide/index.rst | 1 + .../thermal/intel_powerclamp.rst | 22 +++ Documentation/driver-api/thermal/index.rst | 1 - MAINTAINERS | 1 + drivers/thermal/intel/intel_powerclamp.c | 177 +++++++++++++++--- 5 files changed, 180 insertions(+), 22 deletions(-) rename Documentation/{driver-api => admin-guide}/thermal/intel_powerclamp.rst (93%)