| Message ID | 20220529143315.3678563-2-andy.chiu@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable ftrace with kernel preemption for RISC-V | expand |
On Sun, 29 May 2022 07:33:12 PDT (-0700), andy.chiu@sifive.com wrote: > We are introducing a new ftrace mechanism in order to phase out > stop_machine() and enable kernel preemption. The new mechanism requires > ftrace patchable function entries to be 24 bytes and aligned to 4 Byte > boundaries. > > Before applying this patch, the size of the kernel code, with 43432 of > ftrace entries, was at 12.31 MB. Under the same configuration, the size > has increased to 12.68 MB after applying this patch set. > > Signed-off-by: Andy Chiu <andy.chiu@sifive.com> > Reviewed-by: Greentime Hu <greentime.hu@sifive.com> > Reviewed-by: Zong Li <zong.li@sifive.com> > --- > arch/riscv/Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile > index 1f19bdac6767..cb6cfdffc49c 100644 > --- a/arch/riscv/Makefile > +++ b/arch/riscv/Makefile > @@ -11,7 +11,7 @@ LDFLAGS_vmlinux := > ifeq ($(CONFIG_DYNAMIC_FTRACE),y) > LDFLAGS_vmlinux := --no-relax > KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > - CC_FLAGS_FTRACE := -fpatchable-function-entry=8 > + CC_FLAGS_FTRACE := -fpatchable-function-entry=12 -falign-functions=4 > endif > > ifeq ($(CONFIG_CMODEL_MEDLOW),y) Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 1f19bdac6767..cb6cfdffc49c 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -11,7 +11,7 @@ LDFLAGS_vmlinux := ifeq ($(CONFIG_DYNAMIC_FTRACE),y) LDFLAGS_vmlinux := --no-relax KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY - CC_FLAGS_FTRACE := -fpatchable-function-entry=8 + CC_FLAGS_FTRACE := -fpatchable-function-entry=12 -falign-functions=4 endif ifeq ($(CONFIG_CMODEL_MEDLOW),y)