Using -Oline -j 96 W=1 redirect to /tmp/tmp.JpQcZOb0NL and /tmp/tmp.AWpcQeme8Y
LLVM=1 cc="ccache clang"
clang version 21.1.7 (Fedora 21.1.7-1.fc43)
Tree base:
c92510f5e3f8 ("arp: do not assume dev_hard_header() does not change skb->head")
Baseline building the tree
make[1]: Entering directory '/srv/nipa-poller/net/wt-0/build_clang'
  GEN     Makefile
#
# configuration written to .config
#
make[1]: Leaving directory '/srv/nipa-poller/net/wt-0/build_clang'
  SYNC    include/config/auto.conf
  GEN     Makefile
  GEN     Makefile
  DESCEND objtool
  CALL    ../scripts/checksyscalls.sh
  INSTALL libsubcmd_headers
  CC [M]  drivers/net/macvlan.o
  CC [M]  net/ipv4/ip_gre.o
  MODPOST Module.symvers
Kernel: arch/x86/boot/bzImage is ready  (#347)
  CC [M]  drivers/net/macvlan.mod.o
  LD [M]  drivers/net/macvlan.ko
  CC [M]  net/ipv4/ip_gre.mod.o
  LD [M]  net/ipv4/ip_gre.ko
Building the tree before the patch
make[1]: Entering directory '/srv/nipa-poller/net/wt-0/build_clang'
  GEN     Makefile
#
# configuration written to .config
#
make[1]: Leaving directory '/srv/nipa-poller/net/wt-0/build_clang'
  SYNC    include/config/auto.conf
  GEN     Makefile
  GEN     Makefile
  DESCEND objtool
  CALL    ../scripts/checksyscalls.sh
  INSTALL libsubcmd_headers
  CC [M]  net/ipv4/ip_gre.o
  MODPOST Module.symvers
Kernel: arch/x86/boot/bzImage is ready  (#347)
  CC [M]  net/ipv4/ip_gre.mod.o
  LD [M]  net/ipv4/ip_gre.ko
Building the tree with the patch
make[1]: Entering directory '/srv/nipa-poller/net/wt-0/build_clang'
  GEN     Makefile
#
# configuration written to .config
#
make[1]: Leaving directory '/srv/nipa-poller/net/wt-0/build_clang'
  SYNC    include/config/auto.conf
  GEN     Makefile
  GEN     Makefile
  DESCEND objtool
  CALL    ../scripts/checksyscalls.sh
  INSTALL libsubcmd_headers
  CC [M]  net/ipv4/ip_gre.o
  MODPOST Module.symvers
Kernel: arch/x86/boot/bzImage is ready  (#347)
  CC [M]  net/ipv4/ip_gre.mod.o
  LD [M]  net/ipv4/ip_gre.ko