From 347a81fcff5d260263c3b260596543f62ddf7592 Mon Sep 17 00:00:00 2001 From: Jordan Rome Date: Mon, 29 Jan 2024 10:44:44 -0800 Subject: [PATCH] Add BREAKING_CHANGES.md --- BREAKING_CHANGES.md | 23 +++++++++++++++++++++++ README.md | 3 +++ 2 files changed, 26 insertions(+) create mode 100644 BREAKING_CHANGES.md diff --git a/BREAKING_CHANGES.md b/BREAKING_CHANGES.md new file mode 100644 index 0000000..4a3842b --- /dev/null +++ b/BREAKING_CHANGES.md @@ -0,0 +1,23 @@ +# Breaking Changes + +[sched_ext](https://github.com/sched-ext/scx) is still experimental and while we're trying to reduce the number of breaking changes, sometimes they're neccessary to fix bugs or improve the usability. + +Below are the changes in both the sched_ext kernel tree and the associated commits in this repo. + +scx: Rename prep_enable() and cancel_enable(), add exit_task() [[Kernel commit](https://github.com/sched-ext/sched_ext/commit/81e1051116ce50b3b9c99ed3de41927cdb981e77) / [PR](https://github.com/sched-ext/sched_ext/pull/100)] [[scx commit](https://github.com/sched-ext/scx/commit/552b75a9c7513cb3635c06a0ade4abdb227d1dc7)] + +* `ops.prep_enable()` is now called `ops.init_task()` + * `struct scx_enable_args` is now `struct scx_init_task_args` +* `ops.enable()` and `ops.disable()` are now called when a task enters and exits sched_ext respectively. This is the same for when all tasks are using scx, but the callbacks can now be fired multiple times for tasks switching their sched policy. + * No longer passing struct `scx_enable_args *args` to `ops.enable()`. +* `ops.cancel_enable()` has been removed, and `ops.exit_task()` (explained below) is invoked in its stead. +* `ops.exit_task()` has been added, and is called exactly once when a task is exiting if `ops.init_task()` had been successfully invoked on the task previously (or would have been invoked if the callback was defined). + * Called in lieu of `ops.cancel_enable()` as described above + * Called with `struct scx_exit_task_args *args` instead of `scx_enable_args *args`. + +--- + +scx: Add scx_bpf_select_cpu_dfl() kfunc [[Kernel commit](https://github.com/sched-ext/sched_ext/commit/07acdca60031900f7d2ae824951342e0cd98f74e)…[Kernel commit](https://github.com/sched-ext/sched_ext/commit/fadfa2fb5894723302e579a0edbd17b595572d91), [PR](https://github.com/sched-ext/sched_ext/pull/104)] [[scx commit](https://github.com/sched-ext/scx/commit/552b75a9c7513cb3635c06a0ade4abdb227d1dc7)] + +* The default CPU selection logic operates differently now. We no longer pass `SCX_ENQ_LOCAL` when the default CPU selection has found a core to schedule. Callers can instead use `scx_bpf_select_cpu_dfl()` to get the same behavior and then decide whether to direct dispatch or not. +* Tasks can now be direct-dispatched from `ops.select_cpu()`. diff --git a/README.md b/README.md index 1b2162b..8e65dcd 100644 --- a/README.md +++ b/README.md @@ -394,7 +394,10 @@ followings are important branches: [LKML thread](http://lkml.kernel.org/r/20230711011412.100319-1-tj@kernel.org) - [`sched_ext-v5'](https://github.com/sched-ext/sched_ext/tree/sched_ext-v5): [LKML thread](http://lkml.kernel.org/r/20231111024835.2164816-1-tj@kernel.org) + +## [Breaking Changes](./BREAKING_CHANGES.md) +[A list of the breaking changes](./BREAKING_CHANGES.md) in the sched_ext kernel tree and the associated commits for the schedulers in this repo. ## Getting in Touch