From: Tejun Heo Date: Fri, 6 Mar 2026 17:58:03 +0000 (-1000) Subject: sched_ext: When calling ops.dispatch() @prev must be on the same scx_sched X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d94d09a23340b343ffc6ad935f4a7fa90516684a;p=thirdparty%2Flinux.git sched_ext: When calling ops.dispatch() @prev must be on the same scx_sched The @prev parameter passed into ops.dispatch() is expected to be on the same sched. Passing in @prev which isn't on the sched can spuriously trigger failures that can kill the scheduler. Pass in @prev iff it's on the same sched. Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 28ac7ba3ece08..413d0558372f0 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2392,9 +2392,10 @@ static bool scx_dispatch_sched(struct scx_sched *sch, struct rq *rq, struct task_struct *prev) { struct scx_dsp_ctx *dspc = this_cpu_ptr(scx_dsp_ctx); - bool prev_on_scx = prev->sched_class == &ext_sched_class; int nr_loops = SCX_DSP_MAX_LOOPS; s32 cpu = cpu_of(rq); + bool prev_on_sch = (prev->sched_class == &ext_sched_class) && + scx_task_on_sched(sch, prev); if (consume_global_dsq(sch, rq)) return true; @@ -2418,7 +2419,7 @@ static bool scx_dispatch_sched(struct scx_sched *sch, struct rq *rq, dspc->nr_tasks = 0; SCX_CALL_OP(sch, SCX_KF_DISPATCH, dispatch, rq, cpu, - prev_on_scx ? prev : NULL); + prev_on_sch ? prev : NULL); flush_dispatch_buf(sch, rq);