sched_ext: Cleanup [__]scx_exit/error*()

__scx_exit() is the base exit implementation and there are three wrappers on
top of it - scx_exit(), __scx_error() and scx_error(). This is more
confusing than helpful especially given that there are only a couple users
of scx_exit() and __scx_error(). To simplify the situation:

- Make __scx_exit() take va_list and rename it to scx_vexit(). This is to
  ease implementing more complex extensions on top.

- Make scx_exit() a varargs wrapper around __scx_exit(). scx_exit() now
  takes both @kind and @exit_code.

- Convert existing scx_exit() and __scx_error() users to use the new
  scx_exit().

- scx_error() remains unchanged.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index a77b2c4ff80035e2e43bd32ecb9ccf61d6095abd..072e4b1e71e029c2d881924092e33176afb980b6 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1136,17 +1136,20 @@ static struct kset *scx_kset;
 
 static void process_ddsp_deferred_locals(struct rq *rq);
 static void scx_bpf_kick_cpu(s32 cpu, u64 flags);
-static __printf(3, 4) void __scx_exit(enum scx_exit_kind kind, s64 exit_code,
-                                     const char *fmt, ...);
+static void scx_vexit(enum scx_exit_kind kind, s64 exit_code, const char *fmt,
+                     va_list args);
 
-#define __scx_error(err, fmt, args...)                                         \
-       __scx_exit((err), 0, fmt, ##args)
+static __printf(3, 4) void scx_exit(enum scx_exit_kind kind, s64 exit_code,
+                                   const char *fmt, ...)
+{
+       va_list args;
 
-#define scx_exit(code, fmt, args...)                                           \
-       __scx_exit(SCX_EXIT_UNREG_KERN, (code), fmt, ##args)
+       va_start(args, fmt);
+       scx_vexit(kind, exit_code, fmt, args);
+       va_end(args);
+}
 
-#define scx_error(fmt, args...)                                                        \
-       __scx_error(SCX_EXIT_ERROR, fmt, ##args)
+#define scx_error(fmt, args...)                scx_exit(SCX_EXIT_ERROR, 0, fmt, ##args)
 
 #define SCX_HAS_OP(sch, op)    test_bit(SCX_OP_IDX(op), (sch)->has_op)
 
@@ -3554,7 +3557,8 @@ static void handle_hotplug(struct rq *rq, bool online)
        else if (!online && SCX_HAS_OP(sch, cpu_offline))
                SCX_CALL_OP(sch, SCX_KF_UNLOCKED, cpu_offline, NULL, cpu);
        else
-               scx_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
+               scx_exit(SCX_EXIT_UNREG_KERN,
+                        SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
                         "cpu %d going %s, exiting scheduler", cpu,
                         online ? "online" : "offline");
 }
@@ -3595,9 +3599,9 @@ static bool check_rq_for_timeouts(struct rq *rq)
                                        last_runnable + scx_watchdog_timeout))) {
                        u32 dur_ms = jiffies_to_msecs(jiffies - last_runnable);
 
-                       __scx_error(SCX_EXIT_ERROR_STALL,
-                                   "%s[%d] failed to run for %u.%03us",
-                                   p->comm, p->pid, dur_ms / 1000, dur_ms % 1000);
+                       scx_exit(SCX_EXIT_ERROR_STALL, 0,
+                                "%s[%d] failed to run for %u.%03us",
+                                p->comm, p->pid, dur_ms / 1000, dur_ms % 1000);
                        timed_out = true;
                        break;
                }
@@ -3635,9 +3639,9 @@ void scx_tick(struct rq *rq)
                                last_check + READ_ONCE(scx_watchdog_timeout)))) {
                u32 dur_ms = jiffies_to_msecs(jiffies - last_check);
 
-               __scx_error(SCX_EXIT_ERROR_STALL,
-                           "watchdog failed to check in for %u.%03us",
-                           dur_ms / 1000, dur_ms % 1000);
+               scx_exit(SCX_EXIT_ERROR_STALL, 0,
+                        "watchdog failed to check in for %u.%03us",
+                        dur_ms / 1000, dur_ms % 1000);
        }
 
        update_other_load_avgs(rq);
@@ -5263,13 +5267,12 @@ static void scx_error_irq_workfn(struct irq_work *irq_work)
        kthread_queue_work(sch->helper, &sch->disable_work);
 }
 
-static __printf(3, 4) void __scx_exit(enum scx_exit_kind kind, s64 exit_code,
-                                     const char *fmt, ...)
+static void scx_vexit(enum scx_exit_kind kind, s64 exit_code, const char *fmt,
+                     va_list args)
 {
        struct scx_sched *sch;
        struct scx_exit_info *ei;
        int none = SCX_EXIT_NONE;
-       va_list args;
 
        rcu_read_lock();
        sch = rcu_dereference(scx_root);
@@ -5285,9 +5288,7 @@ static __printf(3, 4) void __scx_exit(enum scx_exit_kind kind, s64 exit_code,
        if (kind >= SCX_EXIT_ERROR)
                ei->bt_len = stack_trace_save(ei->bt, SCX_EXIT_BT_LEN, 1);
 #endif
-       va_start(args, fmt);
        vscnprintf(ei->msg, SCX_EXIT_MSG_LEN, fmt, args);
-       va_end(args);
 
        /*
         * Set ei->kind and ->reason for scx_dump_state(). They'll be set again
@@ -5391,7 +5392,8 @@ static void check_hotplug_seq(const struct sched_ext_ops *ops)
        if (ops->hotplug_seq) {
                global_hotplug_seq = atomic_long_read(&scx_hotplug_seq);
                if (ops->hotplug_seq != global_hotplug_seq) {
-                       scx_exit(SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
+                       scx_exit(SCX_EXIT_UNREG_KERN,
+                                SCX_ECODE_ACT_RESTART | SCX_ECODE_RSN_HOTPLUG,
                                 "expected hotplug seq %llu did not match actual %llu",
                                 ops->hotplug_seq, global_hotplug_seq);
                }
@@ -7125,7 +7127,7 @@ __bpf_kfunc void scx_bpf_exit_bstr(s64 exit_code, char *fmt,
 
        raw_spin_lock_irqsave(&scx_exit_bstr_buf_lock, flags);
        if (bstr_format(&scx_exit_bstr_buf, fmt, data, data__sz) >= 0)
-               __scx_exit(SCX_EXIT_UNREG_BPF, exit_code, "%s", scx_exit_bstr_buf.line);
+               scx_exit(SCX_EXIT_UNREG_BPF, exit_code, "%s", scx_exit_bstr_buf.line);
        raw_spin_unlock_irqrestore(&scx_exit_bstr_buf_lock, flags);
 }
 
@@ -7145,7 +7147,7 @@ __bpf_kfunc void scx_bpf_error_bstr(char *fmt, unsigned long long *data,
 
        raw_spin_lock_irqsave(&scx_exit_bstr_buf_lock, flags);
        if (bstr_format(&scx_exit_bstr_buf, fmt, data, data__sz) >= 0)
-               __scx_exit(SCX_EXIT_ERROR_BPF, 0, "%s", scx_exit_bstr_buf.line);
+               scx_exit(SCX_EXIT_ERROR_BPF, 0, "%s", scx_exit_bstr_buf.line);
        raw_spin_unlock_irqrestore(&scx_exit_bstr_buf_lock, flags);
 }