From: Zhang Qiao <zhangqiao22@huawei.com>
To: <corbet@lwn.net>
Cc: <mingo@kernel.org>, <chrubis@suse.cz>, <zhangqiao22@huawei.com>,
<linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] sched/Documentation: Add RT_RUNTIME_SHARE documentation
Date: Wed, 31 Jan 2024 20:32:38 +0800 [thread overview]
Message-ID: <20240131123238.2332064-1-zhangqiao22@huawei.com> (raw)
RT_RUNTIME_SHARE is an important strategy for rt bandwidth, and
we should document this sched feature.
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
---
Documentation/scheduler/sched-rt-group.rst | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/scheduler/sched-rt-group.rst b/Documentation/scheduler/sched-rt-group.rst
index d685609ed3d7..4d8eceb71f5e 100644
--- a/Documentation/scheduler/sched-rt-group.rst
+++ b/Documentation/scheduler/sched-rt-group.rst
@@ -12,6 +12,7 @@ Real-Time group scheduling
2.1 System-wide settings
2.2 Default behaviour
2.3 Basis for grouping tasks
+ 2.4 RT_RUNTIME_SHARE sched feature
3. Future plans
@@ -146,6 +147,16 @@ For now, this can be simplified to just the following (but see Future plans):
\Sum_{i} runtime_{i} <= global_runtime
+2.4 RT_RUNTIME_SHARE sched feature
+----------------------------
+
+RT_RUNTIME_SHARE allows a cpu borrows rt-runtime from other cpus if it runs
+out of its own rt-runtime.
+
+With this feature enabled, a rt-task probably hits 100% cpu usage and starves
+per-cpu tasks like kworkers, as a result, it may hang up the whole system.
+Therefore, in order to avoid such exception, recommand to disable this feature
+by default unless you really know what you're up to.
3. Future plans
===============
--
2.18.0.huawei.25
next reply other threads:[~2024-01-31 12:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-31 12:32 Zhang Qiao [this message]
2024-02-28 22:44 ` [PATCH] sched/Documentation: Add RT_RUNTIME_SHARE documentation Jonathan Corbet
2024-03-24 3:54 ` Zhang Qiao
2024-04-09 7:25 ` Zhang Qiao
2024-04-12 2:50 ` Bagas Sanjaya
2024-04-19 8:51 ` Zhang Qiao
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