From: Chengming Zhou <zhouchengming@bytedance.com>
Date: Thu, 30 Jul 2020 12:31:04 +0000 (+0800)
Subject: iocost_monitor: start from the oldest usage index
X-Git-Tag: sched-urgent-2020-08-15~62^2~7
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1bf6ece5731db14f1556637494d2048a8bb15a41;p=users%2Fdwmw2%2Flinux.git

iocost_monitor: start from the oldest usage index

iocg usage_idx is the latest usage index, we should start from the
oldest usage index to show the consecutive NR_USAGE_SLOTS usages.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/tools/cgroup/iocost_monitor.py b/tools/cgroup/iocost_monitor.py
index 3c21de88af9e5..f4699f9b46ba7 100644
--- a/tools/cgroup/iocost_monitor.py
+++ b/tools/cgroup/iocost_monitor.py
@@ -173,7 +173,7 @@ class IocgStat:
         self.usages = []
         self.usage = 0
         for i in range(NR_USAGE_SLOTS):
-            usage = iocg.usages[(usage_idx + i) % NR_USAGE_SLOTS].value_()
+            usage = iocg.usages[(usage_idx + 1 + i) % NR_USAGE_SLOTS].value_()
             upct = usage * 100 / HWEIGHT_WHOLE
             self.usages.append(upct)
             self.usage = max(self.usage, upct)