[RFC PATCH v6 7/7] x86/unwind/orc: remove run-time ORC unwind tables sort

[Shile Zhang]

The orc_unwind and orc_unwind_ip tables are sorted in vmlinux link phase
at build time, just remove the run-time sort.

Signed-off-by: Shile Zhang <shile.zhang@xxxxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/x86/kernel/unwind_orc.c | 8 +++++---
 scripts/link-vmlinux.sh      | 5 ++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c
index 332ae6530fa8..280da6fa9922 100644
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -273,9 +273,11 @@ void __init unwind_init(void)
 		return;
 	}
 
-	/* Sort the .orc_unwind and .orc_unwind_ip tables: */
-	sort(__start_orc_unwind_ip, num_entries, sizeof(int), orc_sort_cmp,
-	     orc_sort_swap);
+	/*
+	 * Note, orc_unwind and orc_unwind_ip tables has been sorted in
+	 * vmlinux link phase by sorttable tool at build time.
+	 * Its ready for binary search now.
+	 */
 
 	/* Initialize the fast lookup table: */
 	lookup_num_blocks = orc_lookup_end - orc_lookup;
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 01978d1e4c13..f0f08e2bbcd5 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -300,7 +300,10 @@ vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
 
 if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
 	info SORTTAB vmlinux
-	sorttable vmlinux
+	if ! sorttable vmlinux; then
+		echo >&2 Failed to sort kernel tables
+		exit 1
+	fi
 fi
 
 info SYSMAP System.map
-- 
2.24.0.rc2