Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Documentation updates

 - Miscellaneous fixes

 - Callback-offload updates, perhaps most notably a new
   RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be
   offloaded at boot time, regardless of kernel boot parameters.

   This is useful to battery-powered systems such as ChromeOS and
   Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot
   parameter prevents offloaded callbacks from interfering with
   real-time workloads and with energy-efficiency mechanisms

 - Polled grace-period updates, perhaps most notably making these APIs
   account for both normal and expedited grace periods

 - Tasks RCU updates, perhaps most notably reducing the CPU overhead of
   RCU tasks trace grace periods by more than a factor of two on a
   system with 15,000 tasks.

   The reduction is expected to increase with the number of tasks, so it
   seems reasonable to hypothesize that a system with 150,000 tasks
   might see a 20-fold reduction in CPU overhead

 - Torture-test updates

 - Updates that merge RCU's dyntick-idle tracking into context tracking,
   thus reducing the overhead of transitioning to kernel mode from
   either idle or nohz_full userspace execution for kernels that track
   context independently of RCU.

   This is expected to be helpful primarily for kernels built with
   CONFIG_NO_HZ_FULL=y

* tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits)
  rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings
  rcu: Diagnose extended sync_rcu_do_polled_gp() loops
  rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings
  rcutorture: Test polled expedited grace-period primitives
  rcu: Add polled expedited grace-period primitives
  rcutorture: Verify that polled GP API sees synchronous grace periods
  rcu: Make Tiny RCU grace periods visible to polled APIs
  rcu: Make polled grace-period API account for expedited grace periods
  rcu: Switch polled grace-period APIs to ->gp_seq_polled
  rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty
  rcu/nocb: Add option to opt rcuo kthreads out of RT priority
  rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread()
  rcu/nocb: Add an option to offload all CPUs on boot
  rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call
  rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order
  rcu/nocb: Add/del rdp to iterate from rcuog itself
  rcu/tree: Add comment to describe GP-done condition in fqs loop
  rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs()
  rcu/kvfree: Remove useless monitor_todo flag
  rcu: Cleanup RCU urgency state for offline CPU
  ...

3 files changed, 7 insertions, 11 deletions

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
index f17000a2ccf1..ed0ec7f0927e 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh
@@ -35,7 +35,7 @@ then
 	exit 1
 fi
 
-# Remember where we started so that we can get back and the end.
+# Remember where we started so that we can get back at the end.
 curcommit="`git status | head -1 | awk '{ print $NF }'`"
 
 nfail=0
@@ -73,15 +73,10 @@ do
 		# Test the specified commit.
 		git checkout $i > $resdir/$ds/$idir/git-checkout.out 2>&1
 		echo git checkout return code: $? "(Commit $ntry: $i)"
-		kvm.sh --allcpus --duration 3 --trust-make > $resdir/$ds/$idir/kvm.sh.out 2>&1
+		kvm.sh --allcpus --duration 3 --trust-make --datestamp "$ds/$idir" > $resdir/$ds/$idir/kvm.sh.out 2>&1
 		ret=$?
 		echo kvm.sh return code $ret for commit $i from branch $gitbr
-
-		# Move the build products to their resting place.
-		runresdir="`grep -m 1 '^Results directory:' < $resdir/$ds/$idir/kvm.sh.out | sed -e 's/^Results directory://'`"
-		mv $runresdir $resdir/$ds/$idir
-		rrd="`echo $runresdir | sed -e 's,^.*/,,'`"
-		echo Run results: $resdir/$ds/$idir/$rrd
+		echo Run results: $resdir/$ds/$idir
 		if test "$ret" -ne 0
 		then
 			# Failure, so leave all evidence intact.
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
index 0ff59bd8b640..9f0a5d5ff2dd 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-remote.sh
@@ -262,6 +262,7 @@ echo All batches started. `date` | tee -a "$oldrun/remote-log"
 # Wait for all remaining scenarios to complete and collect results.
 for i in $systems
 do
+	echo " ---" Waiting for $i `date` | tee -a "$oldrun/remote-log"
 	while checkremotefile "$i" "$resdir/$ds/remote.run"
 	do
 		sleep 30
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 263e16aeca0e..6c734818a875 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -164,7 +164,7 @@ do
 		shift
 		;;
 	--gdb)
-		TORTURE_KCONFIG_GDB_ARG="CONFIG_DEBUG_INFO=y"; export TORTURE_KCONFIG_GDB_ARG
+		TORTURE_KCONFIG_GDB_ARG="CONFIG_DEBUG_INFO_NONE=n CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y"; export TORTURE_KCONFIG_GDB_ARG
 		TORTURE_BOOT_GDB_ARG="nokaslr"; export TORTURE_BOOT_GDB_ARG
 		TORTURE_QEMU_GDB_ARG="-s -S"; export TORTURE_QEMU_GDB_ARG
 		;;
@@ -180,7 +180,7 @@ do
 		shift
 		;;
 	--kasan)
-		TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
+		TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO_NONE=n CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
 		if test -n "$torture_qemu_mem_default"
 		then
 			TORTURE_QEMU_MEM=2G
@@ -192,7 +192,7 @@ do
 		shift
 		;;
 	--kcsan)
-		TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_STRICT=y CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y"; export TORTURE_KCONFIG_KCSAN_ARG
+		TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO_NONE=n CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y CONFIG_KCSAN=y CONFIG_KCSAN_STRICT=y CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y"; export TORTURE_KCONFIG_KCSAN_ARG
 		;;
 	--kmake-arg|--kmake-args)
 		checkarg --kmake-arg "(kernel make arguments)" $# "$2" '.*' '^error$'