From: <pbhagavatula@marvell.com>
Cc: <stephen@networkplumber.org>, <jerinj@marvell.com>,
<dev@dpdk.org>, "Pavan Nikhilesh" <pbhagavatula@marvell.com>
Subject: [PATCH v3] doc: update Linux core isolation guide
Date: Wed, 18 May 2022 01:29:39 +0530 [thread overview]
Message-ID: <20220517195939.1921-1-pbhagavatula@marvell.com> (raw)
In-Reply-To: <20220517180856.1139-1-pbhagavatula@marvell.com>
From: Pavan Nikhilesh <pbhagavatula@marvell.com>
Update Linux core isolation guide to include isolation from
timers, rcu processing and IRQs.
Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
---
v3 Changes:
- Add additional information links for Cgroups.
v2 Changes:
- Add references to the parameters used.
- Add note about Linux cgroups.
doc/guides/linux_gsg/enable_func.rst | 35 ++++++++++++++++++++++++----
1 file changed, 30 insertions(+), 5 deletions(-)
diff --git a/doc/guides/linux_gsg/enable_func.rst b/doc/guides/linux_gsg/enable_func.rst
index 1df3ab0255..c989674422 100644
--- a/doc/guides/linux_gsg/enable_func.rst
+++ b/doc/guides/linux_gsg/enable_func.rst
@@ -90,16 +90,41 @@ Using Linux Core Isolation to Reduce Context Switches
-----------------------------------------------------
While the threads used by a DPDK application are pinned to logical cores on the system,
-it is possible for the Linux scheduler to run other tasks on those cores also.
-To help prevent additional workloads from running on those cores,
-it is possible to use the ``isolcpus`` Linux kernel parameter to isolate them from the general Linux scheduler.
+it is possible for the Linux scheduler to run other tasks on those cores.
+To help prevent additional workloads, timers, rcu processing and IRQs from running on those cores, it is possible to use
+the Linux kernel parameters ``isolcpus``, ``nohz_full``, ``irqaffinity`` to isolate them from the general Linux scheduler tasks.
-For example, if DPDK applications are to run on logical cores 2, 4 and 6,
+For example, if a given CPU has 0-7 cores and DPDK applications are to run on logical cores 2, 4 and 6,
the following should be added to the kernel parameter list:
.. code-block:: console
- isolcpus=2,4,6
+ isolcpus=2,4,6 nohz_full=2,4,6 irqaffinity=0,1,3,5,7
+
+.. Note::
+
+ More detailed information about the above parameters can be found at
+ https://www.kernel.org/doc/html/latest/timers/no_hz.html
+ https://www.kernel.org/doc/html/latest/core-api/irq/
+ https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html
+
+
+For more fine grained control over resource management and performance tuning one can look
+into ``Linux cgroups``.
+
+Cpusets using cgroups::
+
+ https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v1/cpusets.html
+
+Systemd (CPUAffinity)::
+
+ https://www.freedesktop.org/software/systemd/man/systemd.exec.html
+
+Also, see::
+
+ https://man7.org/linux/man-pages/man7/cpuset.7.html
+ https://www.suse.com/c/cpu-isolation-practical-example-part-5/
+ https://www.rcannings.com/systemd-core-isolation/
.. _High_Precision_Event_Timer:
--
2.25.1
next prev parent reply other threads:[~2022-05-17 19:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-02 7:24 [PATCH] " Pavan Nikhilesh
2022-05-02 20:17 ` Stephen Hemminger
2022-05-10 15:50 ` [EXT] " Pavan Nikhilesh Bhagavatula
2022-05-17 18:08 ` [PATCH v2] " pbhagavatula
2022-05-17 18:22 ` Stephen Hemminger
2022-05-17 18:32 ` [EXT] " Pavan Nikhilesh Bhagavatula
2022-05-17 19:59 ` pbhagavatula [this message]
2022-06-02 7:47 ` [PATCH v3] " Jerin Jacob
2022-07-11 20:59 ` Thomas Monjalon
2022-10-31 11:57 ` [PATCH v4] " pbhagavatula
2022-11-15 15:57 ` Thomas Monjalon
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