build: speed up kernel symbol export stripping

GNU grep has a high per-expression setup overhead when compiling regular
expressions. Use -F to force it to interpret the input as fixed strings,
which is much faster (fraction of a second instead of multiple minutes).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
SVN-Revision: 39049

diff --git a/include/kernel-build.mk b/include/kernel-build.mk
index 27c7aee17ad735feb1847f39471c9f2bd0cb0d78..d34365837d6476feb5be155c035da73362400116 100644 (file)
--- a/include/kernel-build.mk
+++ b/include/kernel-build.mk
@@ -76,9 +76,9 @@ define BuildKernel
                xargs $(TARGET_CROSS)nm | \
                awk '$$$$1 == "U" { print $$$$2 } ' | \
                sort -u > $(KERNEL_BUILD_DIR)/mod_symtab.txt
-       $(TARGET_CROSS)nm -n $(LINUX_DIR)/vmlinux.o | grep ' r __ksymtab' | sed -e 's,........ r __ksymtab_,,' > $(KERNEL_BUILD_DIR)/kernel_symtab.txt
-       grep -f $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_include.txt
-       grep -vf $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_exclude.txt
+       $(TARGET_CROSS)nm -n $(LINUX_DIR)/vmlinux.o | grep -F ' r __ksymtab' | sed -e 's,........ r __ksymtab_,,' > $(KERNEL_BUILD_DIR)/kernel_symtab.txt
+       grep -Ff $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_include.txt
+       grep -Fvf $(KERNEL_BUILD_DIR)/mod_symtab.txt $(KERNEL_BUILD_DIR)/kernel_symtab.txt > $(KERNEL_BUILD_DIR)/sym_exclude.txt
        ( \
                echo '#define SYMTAB_KEEP \'; \
                cat $(KERNEL_BUILD_DIR)/sym_include.txt | \