scripts/sorttable: Implement build-time ORC unwind table sorting
The ORC unwinder has two tables: .orc_unwind_ip and .orc_unwind, which
need to be sorted for binary search. Previously this sorting was done
during bootup.
Sort them at build time to speed up booting.
Add the ORC tables sorting in a parallel build process to speed up the build.
[ mingo: Rewrote the changelog and fixed some comments. ]
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-7-shile.zhang@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/scripts/Makefile b/scripts/Makefile
index 7491241..b0e9626 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -24,6 +24,15 @@
HOSTLDLIBS_sign-file = -lcrypto
HOSTLDLIBS_extract-cert = -lcrypto
+ifdef CONFIG_UNWINDER_ORC
+ifeq ($(ARCH),x86_64)
+ARCH := x86
+endif
+HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include
+HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
+HOSTLDLIBS_sorttable = -lpthread
+endif
+
always := $(hostprogs-y) $(hostprogs-m)
# The following hostprogs-y programs are only build on demand