linux-kernel - [PATCH] Update ToDo with ideas for per_cpu

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Message-ID: <20191029222112.43040-1-Janakarajan.Natarajan@amd.com>
Date:   Tue, 29 Oct 2019 22:21:24 +0000
From:   "Natarajan, Janakarajan" <Janakarajan.Natarajan@....com>
To:     "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Thomas Renninger <trenn@...e.com>, Shuah Khan <shuah@...nel.org>,
        "Natarajan, Janakarajan" <Janakarajan.Natarajan@....com>
Subject: [PATCH] Update ToDo with ideas for per_cpu_schedule handling

Re-structure the code to better handle the per_cpu_schedule mechanism,
which was introduced when updating cpupower for AMD Zen based processors.

Based on Thomas Renninger's feedback/ideas.

Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@....com>
---
 tools/power/cpupower/ToDo | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/power/cpupower/ToDo b/tools/power/cpupower/ToDo
index 6e8b89f282e6..3f12ee451403 100644
--- a/tools/power/cpupower/ToDo
+++ b/tools/power/cpupower/ToDo
@@ -8,3 +8,17 @@ ToDos sorted by priority:
 - Add another c1e debug idle monitor
   -> Is by design racy with BIOS, but could be added
      with a --force option and some "be careful" messages
+- Add cpu_start()/cpu_stop() callbacks for monitor
+  -> This is to move the per_cpu_schedule logic from inside
+     the monitor to outside it. This can be given higher
+     priority in fork_it. The per_cpu logic allows the
+     cpupower process to move to each cpu before taking
+     measurements.
+- Fork as many processes as there are CPUs in case the
+  per_cpu_schedule flag is set.
+  -> Bind forked processes to each cpu.
+  -> Execute start measures via the forked processes on
+     each cpu.
+  -> Run test executable in a forked process.
+  -> Execute stop measures via the forked processes on
+     each cpu.
-- 
2.17.1