From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 27 Mar 2025 23:03:52 +0000 (-0700)
Subject: Merge tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: nvme-6.15-2025-04-02~68
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=88221ac0d560700b50493aedc768f728aa585141;p=nvme.git

Merge tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull latency tracing updates from Steven Rostedt:

 - Add some trace events to osnoise and timerlat sample generation

   This adds more information to the osnoise and timerlat tracers as
   well as allows BPF programs to be attached to these locations to
   extract even more data.

 - Fix to DECLARE_TRACE_CONDITION() macro

   It wasn't used but now will be and it happened to be broken causing
   the build to fail.

 - Add scheduler specification monitors to runtime verifier (RV)

   This is a continuation of Daniel Bristot's work.

   RV allows monitors to run and react concurrently. Running the
   cumulative model is equivalent to running single components using the
   same reactors, with the advantage that it's easier to point out which
   specification failed in case of error.

   This update introduces nested monitors to RV, in short, the sysfs
   monitor folder will contain a monitor named sched, which is nothing
   but an empty container for other monitors. Controlling the sched
   monitor (enable, disable, set reactors) controls all nested monitors.

   The following scheduling monitors are added:

     - sco: scheduling context operations
       Monitor to ensure sched_set_state happens only in thread context

     - tss: task switch while scheduling
       Monitor to ensure sched_switch happens only in scheduling context

     - snroc: set non runnable on its own context
       Monitor to ensure set_state happens only in the respective task's context

     - scpd: schedule called with preemption disabled
       Monitor to ensure schedule is called with preemption disabled

     - snep: schedule does not enable preempt
       Monitor to ensure schedule does not enable preempt

     - sncid: schedule not called with interrupt disabled
       Monitor to ensure schedule is not called with interrupt disabled

* tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tools/rv: Allow rv list to filter for container
  Documentation/rv: Add docs for the sched monitors
  verification/dot2k: Add support for nested monitors
  tools/rv: Add support for nested monitors
  rv: Add scpd, snep and sncid per-cpu monitors
  rv: Add snroc per-task monitor
  rv: Add sco and tss per-cpu monitors
  rv: Add option for nested monitors and include sched
  sched: Add sched tracepoints for RV task model
  rv: Add license identifiers to monitor files
  tracing: Fix DECLARE_TRACE_CONDITION
  trace/osnoise: Add trace events for samples
---

88221ac0d560700b50493aedc768f728aa585141
diff --cc kernel/sched/core.c
index 87540217fc09,8294bf49b62b..cfaca3040b2f
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@@ -6703,9 -6738,12 +6722,10 @@@ static void __sched notrace __schedule(
  picked:
  	clear_tsk_need_resched(prev);
  	clear_preempt_need_resched();
 -#ifdef CONFIG_SCHED_DEBUG
  	rq->last_seen_need_resched_ns = 0;
 -#endif
  
- 	if (likely(prev != next)) {
+ 	is_switch = prev != next;
+ 	if (likely(is_switch)) {
  		rq->nr_switches++;
  		/*
  		 * RCU users of rcu_dereference(rq->curr) may not see