scx/scheds/rust/scx_bpfland/build.rs

// Copyright (c) Andrea Righi <andrea.righi@linux.dev>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2.

fn main() {
    scx_utils::BpfBuilder::new()
        .unwrap()
        .enable_intf("src/bpf/intf.h", "bpf_intf.rs")
        .enable_skel("src/bpf/main.bpf.c", "bpf")
        .build()
        .unwrap();
}
scx_bpfland: update copyright info Signed-off-by: Andrea Righi <andrea.righi@linux.dev> 2024-08-12 07:58:07 +01:00			`// Copyright (c) Andrea Righi <andrea.righi@linux.dev>`
scheds: introduce scx_bpfland Overview ======== This scheduler is derived from scx_rustland, but it is fully implemented in BFP with minimal user-space Rust part to process command line options, collect metrics and logs out scheduling statistics. Unlike scx_rustland, all scheduling decisions are made by the BPF component. Motivation ========== The primary goal of this scheduler is to act as a performance baseline for comparison with scx_rustland, allowing for a better assessment of the overhead caused by kernel/user-space interactions. It can also be used to deploy prototypes initially tested in the scx_rustland scheduler. In fact, this scheduler is expected to outperform scx_rustland, due to the elimitation of the kernel/user-space overhead. Scheduling policy ================= scx_bpfland is a vruntime-based sched_ext scheduler that prioritizes interactive workloads. Its scheduling policy closely mirrors scx_rustland, but it has been re-implemented in BPF with some small adjustments. Tasks are categorized as either interactive or regular based on their average rate of voluntary context switches per second: tasks that exceed a specific voluntary context switch threshold are classified as interactive. Interactive tasks are prioritized in a higher-priority DSQ, while regular tasks are placed in a lower-priority DSQ. Within each queue, tasks are sorted based on their weighted runtime, using the built-in scx vtime ordering capabilities (scx_bpf_dispatch_vtime()). Moreover, each task gets a time slice budget. When a task is dispatched, it receives a time slice equivalent to the remaining unused portion of its previously allocated time slice (with a minimum threshold applied). This gives latency-sensitive workloads more chances to exceed their time slice when needed to perform short bursts of CPU activity without being interrupted (i.e., real-time audio encoding / decoding workloads). Results ======= According to the initial test results, using the same benchmark "playing a videogame while recompiling the kernel", this scheduler seems to provide a +5% improvement in the frames-per-second (fps) compared to scx_rustland, with video games such as Cyberpunk 2077, Counter-Strike 2 and Baldur's Gate 3. Initial test results indicate that this scheduler offers around a +5% improvement in frames-per-second (fps) compared to scx_rustland when using the benchmark "playing a video game while recompiling the kernel". This improvement was observed in games such as Cyberpunk 2077, Counter-Strike 2, and Baldur's Gate 3. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> 2024-06-24 06:56:03 +01:00			`//`
			`// This software may be used and distributed according to the terms of the`
			`// GNU General Public License version 2.`

			`fn main() {`
			`scx_utils::BpfBuilder::new()`
			`.unwrap()`
			`.enable_intf("src/bpf/intf.h", "bpf_intf.rs")`
			`.enable_skel("src/bpf/main.bpf.c", "bpf")`
			`.build()`
			`.unwrap();`
			`}`