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Tejun Heo 9f391f94a1 sched_ext: Disallow loading BPF scheduler if isolcpus= domain isolation is in effect
sched_domains regulate the load balancing for sched_classes. A machine can
be partitioned into multiple sections that are not load-balanced across
using either isolcpus= boot param or cpuset partitions. In such cases, tasks
that are in one partition are expected to stay within that partition.

cpuset configured partitions are always reflected in each member task's
cpumask. As SCX always honors the task cpumasks, the BPF scheduler is
automatically in compliance with the configured partitions.

However, for isolcpus= domain isolation, the isolated CPUs are simply
omitted from the top-level sched_domain[s] without further restrictions on
tasks' cpumasks, so, for example, a task currently running in an isolated
CPU may have more CPUs in its allowed cpumask while expected to remain on
the same CPU.

There is no straightforward way to enforce this partitioning preemptively on
BPF schedulers and erroring out after a violation can be surprising.
isolcpus= domain isolation is being replaced with cpuset partitions anyway,
so keep it simple and simply disallow loading a BPF scheduler if isolcpus=
domain isolation is in effect.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20240626082342.GY31592@noisy.programming.kicks-ass.net
Cc: David Vernet <void@manifault.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
2024-07-08 09:30:13 -10:00
arch bpf-next-for-netdev 2024-06-10 18:02:14 -07:00
block blk-throttle: Fix incorrect display of io.max 2024-05-30 19:44:29 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation sched_ext: Documentation: Remove mentions of scx_bpf_switch_all 2024-07-02 07:00:13 -10:00
drivers sched_ext: Add sysrq-S which disables the BPF scheduler 2024-06-18 10:09:18 -10:00
fs bpf: treewide: Align kfunc signatures to prog point-of-view 2024-06-12 11:01:31 -07:00
include sched_ext: Documentation: scheduler: Document extensible scheduler class 2024-06-18 10:09:21 -10:00
init sched_ext: Add vtime-ordered priority queue to dispatch_q's 2024-06-18 10:09:21 -10:00
io_uring io_uring/net: assign kmsg inq/flags before buffer selection 2024-05-30 14:04:37 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel sched_ext: Disallow loading BPF scheduler if isolcpus= domain isolation is in effect 2024-07-08 09:30:13 -10:00
lib sched_ext: Print sched_ext info when dumping stack 2024-06-18 10:09:18 -10:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
net bpf: Relax tuple len requirement for sk helpers. 2024-06-14 21:52:39 +02:00
rust LoongArch changes for v6.10 2024-05-22 09:43:07 -07:00
samples bpf-next-for-netdev 2024-05-28 07:27:29 -07:00
scripts kbuild: bpf: Tell pahole to DECL_TAG kfuncs 2024-06-12 11:01:30 -07:00
security tomoyo: update project links 2024-06-03 22:43:11 +09:00
sound ALSA: seq: ump: Fix swapped song position pointer data 2024-05-31 09:51:44 +02:00
tools sched/ext: Add BPF function to fetch rq 2024-07-08 07:10:48 -10:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap mailmap: update entry for Kees Cook 2024-05-31 08:58:36 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS sched_ext: Implement BPF extensible scheduler class 2024-06-18 10:09:17 -10:00
Makefile sched_ext: Drop tools_clean target from the top-level Makefile 2024-06-24 16:00:37 -10:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.