don't reapply the profile on each boot

enhancements/microshift/low-latency-workloads-on-microshift.md

@@ -107,12 +107,12 @@ Workflow consists of two parts:
 1. User deploys the commit / installs the system.
 1. System boots
 1. `microshift-tuned.service` starts (after `tuned.service`, before `microshift.service`):
-   - Saves current kernel args
-   - Applies tuned `microshift-baseline` profile
-   - Verifies expected kernel args
-     - ostree: `rpm-ostree kargs` or checking if new deployment was created[0]
-     - rpm: `grubby`
-   - If the current and expected kernel args are different, reboot the node
+   - Queries tuned for active profile
+   - Compares active profile with requested profile
+   - If profile are the same: do nothing, exit.
+   - If profiles are different:
+     - Apply requested profile
+     - If `reboot_after_apply` is True, then reboot the host
 1. Host boots again, everything for low latency is in place,
    `microshift.service` can continue start up.
 
@@ -163,7 +163,7 @@ kubelet:
 [[customizations.files]]
 path = "/etc/microshift/microshift-tuned.yaml"
 data = """
-auto_reboot_enabled: True
+reboot_after_apply: True
 profile: microshift-baseline
 """
 ```
@@ -204,14 +204,8 @@ RUN systemctl enable microshift-tuned.service
 1. User creates following configs:
    - `/etc/tuned/microshift-baseline-variables.conf`
    - `/etc/microshift/config.yaml` to configure Kubelet
-   - `/etc/microshift/microshift-tuned.yaml` to configure `microshift-tuned.service`
-1. user starts/enables `microshift-tuned.service`:
-   - Saves current kernel args
-   - Applies tuned `microshift-low-latency` profile
-   - Verifies expected kernel args
-     - ostree: `rpm-ostree kargs`
-     - rpm: `grubby`
-   - If the current and expected kernel args are different, reboots the node
+1. User runs `sudo tuned-adm profile microshift-baseline` to enable the profile.
+1. User reboots the host to make changes to kernel arguments active.
 1. Host boots again, everything for low latency is in place,
 1. User starts/enables `microshift.service`
 
@@ -320,8 +314,8 @@ Config file to specify which profile to re-apply each boot and if host should be
 the kargs before and after applying profile are mismatched.
 
 ```yaml
-auto_reboot_enabled: True
 profile: microshift-baseline
+reboot_after_apply: True
 ```
 
 #### CRI-O configuration
@@ -555,6 +549,13 @@ Responsibility of dev team is to remove common hurdles from user's path so they
 and want to continue using the product.
 
 
+### Applying user requested TuneD profile on every start of the `microshift-tuned.service`
+
+This was preferred option before it was discovered that when profile is applied, tuned will
+first remove all the old kernel args, then append new kernel args resulting in creation of new staged OSTree deployment.
+This happens even if the the same profile is being reapplied.
+
+
 ## Infrastructure Needed [optional]
 
 Nothing.