From 8eff5d59ed7f38ce113c126f03ca93419dc31168 Mon Sep 17 00:00:00 2001 From: Andrew Penner Date: Fri, 1 Apr 2022 21:43:53 +0100 Subject: [PATCH] extra-build-config: Add documentation for the ISOLATED_CPUS configuration variable Signed-off-by: Andrew Penner --- docs/extra-build-config.md | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/docs/extra-build-config.md b/docs/extra-build-config.md index 8c44db4..6c54679 100644 --- a/docs/extra-build-config.md +++ b/docs/extra-build-config.md @@ -278,6 +278,18 @@ the header extension should set the following in local.conf: ENABLE_DWC2_HOST = "1" +## Set CPUs to be isolated from the standard Linux scheduler + +By default Linux will use all available CPUs for scheduling tasks. For real time +purposes there can be an advantage to isolating one or more CPUs from the +standard scheduler. It should be noted that CPU 0 is special, it is the only CPU +available during the early stages of the boot process and cannot be isolated. + +The string assigned to this variable may be a single CPU number, a comma +separated list ("1,2"), a range("1-3"), or a mixture of these ("1,3-5") + + ISOLATED_CPUS = "1-2" + ## Enable Openlabs 802.15.4 radio module When using device tree kernels, set this variable to enable the 802.15.4 hat: