test_arena_spin_lock_size() explicitly requires having at least 2 CPUs,
but if the machine has less than 16, then pthread_setaffinity_np() call
in spin_lock_thread() fails.
Cap threads to the number of CPUs.
Alternative solutions are raising the number of required CPUs to 16, or
pinning multiple threads to the same CPU, but they are not that useful.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20250424165525.154403-3-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Venkat reported a compilation error for BPF selftests on PowerPC [0].
The crux of the error is the following message:
In file included from progs/arena_spin_lock.c:7:
/root/bpf-next/tools/testing/selftests/bpf/bpf_arena_spin_lock.h:122:8:
error: member reference base type '__attribute__((address_space(1)))
u32' (aka '__attribute__((address_space(1))) unsigned int') is not a
structure or union
122 | old = atomic_read(&lock->val);
This is because PowerPC overrides the qspinlock type changing the
lock->val member's type from atomic_t to u32.
To remedy this, import the asm-generic version in the arena spin lock
header, name it __qspinlock (since it's aliased to arena_spinlock_t, the
actual name hardly matters), and adjust the selftest to not depend on
the type in vmlinux.h.
[0]: https://lore.kernel.org/bpf/7bc80a3b-d708-4735-aa3b-6a8c21720f9d@linux.ibm.com
Fixes: 88d706ba7c ("selftests/bpf: Introduce arena spin lock")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20250311154244.3775505-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add some basic selftests for qspinlock built over BPF arena using
cond_break_label macro.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250306035431.2186189-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Ilya Leoshkevich
Kumar Kartikeya Dwivedi