[PATCH] sched_ext: Add __weak markers to BPF helper function decalarations

[PATCH] sched_ext: Add __weak markers to BPF helper function decalarations

[Vishal Chourasia]

Fix build errors by adding __weak markers to BPF helper function
declarations in header files. This resolves static assertion failures
in scx_qmap.bpf.c and scx_flatcg.bpf.c where functions like
scx_bpf_dispatch_from_dsq_set_slice, scx_bpf_dispatch_from_dsq_set_vtime,
and scx_bpf_task_cgroup were missing the __weak attribute.

[1] https://lore.kernel.org/all/ZvvfUqRNM4-jYQzH@linux.ibm.com

Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>
---
 tools/sched_ext/include/scx/common.bpf.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h
index 225f61f9bfca..27749c51c3ec 100644
--- a/tools/sched_ext/include/scx/common.bpf.h
+++ b/tools/sched_ext/include/scx/common.bpf.h
@@ -41,8 +41,8 @@ void scx_bpf_dispatch_vtime(struct task_struct *p, u64 dsq_id, u64 slice, u64 vt
 u32 scx_bpf_dispatch_nr_slots(void) __ksym;
 void scx_bpf_dispatch_cancel(void) __ksym;
 bool scx_bpf_consume(u64 dsq_id) __ksym;
-void scx_bpf_dispatch_from_dsq_set_slice(struct bpf_iter_scx_dsq *it__iter, u64 slice) __ksym;
-void scx_bpf_dispatch_from_dsq_set_vtime(struct bpf_iter_scx_dsq *it__iter, u64 vtime) __ksym;
+void scx_bpf_dispatch_from_dsq_set_slice(struct bpf_iter_scx_dsq *it__iter, u64 slice) __ksym __weak;
+void scx_bpf_dispatch_from_dsq_set_vtime(struct bpf_iter_scx_dsq *it__iter, u64 vtime) __ksym __weak;
 bool scx_bpf_dispatch_from_dsq(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak;
 bool scx_bpf_dispatch_vtime_from_dsq(struct bpf_iter_scx_dsq *it__iter, struct task_struct *p, u64 dsq_id, u64 enq_flags) __ksym __weak;
 u32 scx_bpf_reenqueue_local(void) __ksym;
@@ -71,7 +71,7 @@ s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
 bool scx_bpf_task_running(const struct task_struct *p) __ksym;
 s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;
 struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym;
-struct cgroup *scx_bpf_task_cgroup(struct task_struct *p) __ksym;
+struct cgroup *scx_bpf_task_cgroup(struct task_struct *p) __ksym __weak;
 
 /*
  * Use the following as @it__iter when calling
-- 
2.46.2

Re: [PATCH] sched_ext: Add __weak markers to BPF helper function decalarations

[Tejun Heo]

On Wed, Oct 02, 2024 at 12:38:06PM +0530, Vishal Chourasia wrote:
> Fix build errors by adding __weak markers to BPF helper function
> declarations in header files. This resolves static assertion failures
> in scx_qmap.bpf.c and scx_flatcg.bpf.c where functions like
> scx_bpf_dispatch_from_dsq_set_slice, scx_bpf_dispatch_from_dsq_set_vtime,
> and scx_bpf_task_cgroup were missing the __weak attribute.
> 
> [1] https://lore.kernel.org/all/ZvvfUqRNM4-jYQzH@linux.ibm.com
> 
> Signed-off-by: Vishal Chourasia <vishalc@linux.ibm.com>

Applied to sched_ext/for-6.12-fixes.

Thanks.

-- 
tejun