[ Upstream commit 7980ad7e4c ]
On single-CPU systems, ops.select_cpu() is never called, causing the
EXIT_SELECT_CPU test case to wait indefinitely.
Avoid the stall by skipping this specific sub-test when only one CPU is
available.
Reported-by: Phil Auld <pauld@redhat.com>
Fixes: a5db7817af ("sched_ext: Add selftests")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Tested-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3c7d51b0d2 upstream.
In UP systems p->migration_disabled is not available. Fix this by using
the portable helper is_migration_disabled(p).
Fixes: e9fe182772 ("sched_ext: selftests/dsp_local_on: Fix sporadic failures")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9fe182772 ]
dsp_local_on has several incorrect assumptions, one of which is that
p->nr_cpus_allowed always tracks p->cpus_ptr. This is not true when a task
is scheduled out while migration is disabled - p->cpus_ptr is temporarily
overridden to the previous CPU while p->nr_cpus_allowed remains unchanged.
This led to sporadic test faliures when dsp_local_on_dispatch() tries to put
a migration disabled task to a different CPU. Fix it by keeping the previous
CPU when migration is disabled.
There are SCX schedulers that make use of p->nr_cpus_allowed. They should
also implement explicit handling for p->migration_disabled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ihor Solodrai <ihor.solodrai@pm.me>
Cc: Andrea Righi <arighi@nvidia.com>
Cc: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ce2b93fc1d ]
The dsp_local_on selftest expects the scheduler to fail by trying to
schedule an e.g. CPU-affine task to the wrong CPU. However, this isn't
guaranteed to happen in the 1 second window that the test is running.
Besides, it's odd to have this particular exception path tested when there
are no other tests that verify that the interface is working at all - e.g.
the test would pass if dsp_local_on interface is completely broken and fails
on any attempt.
Flip the test so that it verifies that the feature works. While at it, fix a
typo in the info message.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ihor Solodrai <ihor.solodrai@pm.me>
Link: http://lkml.kernel.org/r/Z1n9v7Z6iNJ-wKmq@slm.duckdns.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b8f614207b ]
maximal.bpf.c is still dispatching to and consuming from SCX_DSQ_GLOBAL.
Let's have it use its own DSQ to avoid any runtime errors.
Signed-off-by: David Vernet <void@manifault.com>
Tested-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cc9877fb76 ("sched_ext: Improve error reporting during loading") changed
how load failures are reported so that more error context can be
communicated. This breaks the enq_last_no_enq_fails test as attach no longer
fails. The scheduler is guaranteed to be ejected on attach completion with
full error information. Update enq_last_no_enq_fails so that it checks that
the scheduler is ejected using ops.exit().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vishal Chourasia <vishalc@linux.ibm.com>
Link: http://lkml.kernel.org/r/Zxknp7RAVNjmdJSc@linux.ibm.com
Fixes: cc9877fb76 ("sched_ext: Improve error reporting during loading")
In commit 63fb3ec805 ("sched_ext: Allow only user DSQs for
scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new()"), we
updated the consume path to only accept user DSQs, thus making it invalid
to consume SCX_DSQ_GLOBAL. This selftest was doing that, so let's create a
custom DSQ and use that instead. The test now passes:
[root@virtme-ng sched_ext]# ./runner -t exit
===== START =====
TEST: exit
DESCRIPTION: Verify we can cleanly exit a scheduler in multiple places
OUTPUT:
[ 12.387229] sched_ext: BPF scheduler "exit" enabled
[ 12.406064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
[ 12.453325] sched_ext: BPF scheduler "exit" enabled
[ 12.474064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
[ 12.515241] sched_ext: BPF scheduler "exit" enabled
[ 12.532064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
[ 12.592063] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
[ 12.654063] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
[ 12.715062] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF)
ok 1 exit #
===== END =====
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fix incompatible function pointer type warnings in sched_ext BPF selftests by
explicitly casting the function pointers when initializing struct_ops.
This addresses multiple -Wincompatible-function-pointer-types warnings from the
clang compiler where function signatures didn't match exactly.
The void * cast ensures the compiler accepts the function pointer
assignment despite minor type differences in the parameters.
Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The sched_ext selftests is missing proper cross-compilation support, a
proper target entry, and out-of-tree build support.
When building the kselftest suite, e.g.:
make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
TARGETS=sched_ext SKIP_TARGETS="" O=/output/foo \
-C tools/testing/selftests install
or:
make ARCH=arm64 LLVM=1 TARGETS=sched_ext SKIP_TARGETS="" \
O=/output/foo -C tools/testing/selftests install
The expectation is that the sched_ext is included, cross-built, the
correct toolchain is picked up, and placed into /output/foo.
In contrast to the BPF selftests, the sched_ext suite does not use
bpftool at test run-time, so it is sufficient to build bpftool for the
build host only.
Add ARCH, CROSS_COMPILE, OUTPUT, and TARGETS support to the sched_ext
selftest. Also, remove some variables that were unused by the
Makefile.
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: David Vernet <void@manifault.com>
Tested-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add sched_ext_ops operations to init/exit cgroups, and track task migrations
and config changes. A BPF scheduler may not implement or implement only
subset of cgroup features. The implemented features can be indicated using
%SCX_OPS_HAS_CGOUP_* flags. If cgroup configuration makes use of features
that are not implemented, a warning is triggered.
While a BPF scheduler is being enabled and disabled, relevant cgroup
operations are locked out using scx_cgroup_rwsem. This avoids situations
like task prep taking place while the task is being moved across cgroups,
making things easier for BPF schedulers.
v7: - cgroup interface file visibility toggling is dropped in favor just
warning messages. Dynamically changing interface visiblity caused more
confusion than helping.
v6: - Updated to reflect the removal of SCX_KF_SLEEPABLE.
- Updated to use CONFIG_GROUP_SCHED_WEIGHT and fixes for
!CONFIG_FAIR_GROUP_SCHED && CONFIG_EXT_GROUP_SCHED.
v5: - Flipped the locking order between scx_cgroup_rwsem and
cpus_read_lock() to avoid locking order conflict w/ cpuset. Better
documentation around locking.
- sched_move_task() takes an early exit if the source and destination
are identical. This triggered the warning in scx_cgroup_can_attach()
as it left p->scx.cgrp_moving_from uncleared. Updated the cgroup
migration path so that ops.cgroup_prep_move() is skipped for identity
migrations so that its invocations always match ops.cgroup_move()
one-to-one.
v4: - Example schedulers moved into their own patches.
- Fix build failure when !CONFIG_CGROUP_SCHED, reported by Andrea Righi.
v3: - Make scx_example_pair switch all tasks by default.
- Convert to BPF inline iterators.
- scx_bpf_task_cgroup() is added to determine the current cgroup from
CPU controller's POV. This allows BPF schedulers to accurately track
CPU cgroup membership.
- scx_example_flatcg added. This demonstrates flattened hierarchy
implementation of CPU cgroup control and shows significant performance
improvement when cgroups which are nested multiple levels are under
competition.
v2: - Build fixes for different CONFIG combinations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
We already have some testcases verifying that we can call
BPF_PROG_TYPE_SYSCALL progs and invoke scx_bpf_exit(). Let's extend that to
also call scx_bpf_create_dsq() so we get coverage for that as well.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
