From 9dd0531b32c2a69d2dee124ef2bdea35ee552f47 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <frederic@kernel.org>
Date: Wed, 2 Feb 2022 15:59:54 +0100
Subject: [PATCH] sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers
Patch-mainline: Not yet, on review
References: bsc#1194889
Displaying "PREEMPT" on kernel headers when CONFIG_PREEMPT_DYNAMIC=y
can be misleading for anybody involved in remote debugging because it
is then not guaranteed that there is an actual preemption behaviour. It
depends on default Kconfig or boot defined choices.
Therefore, tell about PREEMPT_DYNAMIC on static kernel headers and leave
the search for the actual preemption behaviour to browsing dmesg.
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbecker@suse.de>
---
init/Makefile | 3 ++-
scripts/mkcompile_h | 17 ++++++++++++-----
2 files changed, 14 insertions(+), 6 deletions(-)
--- a/init/Makefile
+++ b/init/Makefile
@@ -31,7 +31,8 @@ quiet_cmd_compile.h = CHK $@
cmd_compile.h = \
$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@ \
"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)" \
- "$(CONFIG_PREEMPT_RT)" $(CONFIG_CC_VERSION_TEXT) "$(LD)"
+ "$(CONFIG_PREEMPT_DYNAMIC)" "$(CONFIG_PREEMPT_RT)" \
+ $(CONFIG_CC_VERSION_TEXT) "$(LD)"
include/generated/compile.h: FORCE
$(call cmd,compile.h)
--- a/scripts/mkcompile_h
+++ b/scripts/mkcompile_h
@@ -5,9 +5,10 @@ TARGET=$1
ARCH=$2
SMP=$3
PREEMPT=$4
-PREEMPT_RT=$5
-CC_VERSION="$6"
-LD=$7
+PREEMPT_DYNAMIC=$5
+PREEMPT_RT=$6
+CC_VERSION="$7"
+LD=$8
# Do not expand names
set -f
@@ -41,8 +42,14 @@ fi
UTS_VERSION="#$VERSION"
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
-if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
-if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi
+
+if [ -n "$PREEMPT_RT" ] ; then
+ CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"
+elif [ -n "$PREEMPT_DYNAMIC" ] ; then
+ CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_DYNAMIC"
+elif [ -n "$PREEMPT" ] ; then
+ CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"
+fi
# Truncate to maximum length
UTS_LEN=64