kernel: Activate CONFIG_OPTIMIZE_INLINING

This will reduce the size of the kernel if CONFIG_CC_OPTIMIZE_FOR_SIZE is
set like for all targets with small_flash feature flag.
I haven't seen any changes for an ARM64 target which optimizes the
kernel for speed instead.

On the ath79/tiny target the uncompressed kernel size was reduced by
3.2% and the compressed kernel size by 2.1%

kernel size with CONFIG_OPTIMIZE_INLINING=n
4346412 build_dir/target-mips_24kc_musl/linux-ath79_tiny/vmlinux
1391169 build_dir/target-mips_24kc_musl/linux-ath79_tiny/tplink_tl-wr941-v4-kernel.bin

Kernel size with CONFIG_OPTIMIZE_INLINING=y
4212396 build_dir/target-mips_24kc_musl/linux-ath79_tiny/vmlinux
1362051 build_dir/target-mips_24kc_musl/linux-ath79_tiny/tplink_tl-wr941-v4-kernel.bin

This change is currently pending for kernel 5.2 and already in
linux-next, this updates our patch to match the upstream version.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 6dac1c0a9b94b62b6412b74a8997f728570f36be)

diff --git a/target/linux/generic/config-4.14 b/target/linux/generic/config-4.14
index 1e8497b503d1e726d1f36029895b16910e8eaf9c..8aaa54b8ff1963e13480a14a0422b0ca612f5239 100644 (file)
--- a/target/linux/generic/config-4.14
+++ b/target/linux/generic/config-4.14
@@ -3382,7 +3382,7 @@ CONFIG_NMI_LOG_BUF_SHIFT=13
 # CONFIG_OPROFILE is not set
 # CONFIG_OPROFILE_EVENT_MULTIPLEX is not set
 # CONFIG_OPT3001 is not set
-# CONFIG_OPTIMIZE_INLINING is not set
+CONFIG_OPTIMIZE_INLINING=y
 # CONFIG_ORANGEFS_FS is not set
 # CONFIG_ORION_WATCHDOG is not set
 # CONFIG_OSF_PARTITION is not set

diff --git a/target/linux/generic/pending-4.14/220-optimize_inlining.patch b/target/linux/generic/pending-4.14/220-optimize_inlining.patch
index dca1dcb20417eb208dea6eb388a7f4a50a8257c0..ff2bed17f31cdfd964a90e7e434225e3900ff0aa 100644 (file)
--- a/target/linux/generic/pending-4.14/220-optimize_inlining.patch
+++ b/target/linux/generic/pending-4.14/220-optimize_inlining.patch
@@ -1,3 +1,98 @@
+--- a/arch/arm/kernel/atags.h
++++ b/arch/arm/kernel/atags.h
+@@ -5,7 +5,7 @@ void convert_to_tag_list(struct tag *tag
+ const struct machine_desc *setup_machine_tags(phys_addr_t __atags_pointer,
+       unsigned int machine_nr);
+ #else
+-static inline const struct machine_desc *
++static inline const struct machine_desc * __init __noreturn
+ setup_machine_tags(phys_addr_t __atags_pointer, unsigned int machine_nr)
+ {
+       early_print("no ATAGS support: can't continue\n");
+--- a/arch/arm64/include/asm/cpufeature.h
++++ b/arch/arm64/include/asm/cpufeature.h
+@@ -126,7 +126,7 @@ static inline bool cpu_have_feature(unsi
+ }
+ 
+ /* System capability check for constant caps */
+-static inline bool __cpus_have_const_cap(int num)
++static __always_inline bool __cpus_have_const_cap(int num)
+ {
+       if (num >= ARM64_NCAPS)
+               return false;
+@@ -140,7 +140,7 @@ static inline bool cpus_have_cap(unsigne
+       return test_bit(num, cpu_hwcaps);
+ }
+ 
+-static inline bool cpus_have_const_cap(int num)
++static __always_inline bool cpus_have_const_cap(int num)
+ {
+       if (static_branch_likely(&arm64_const_caps_ready))
+               return __cpus_have_const_cap(num);
+--- a/arch/mips/include/asm/bitops.h
++++ b/arch/mips/include/asm/bitops.h
+@@ -462,7 +462,7 @@ static inline void __clear_bit_unlock(un
+  * Return the bit position (0..63) of the most significant 1 bit in a word
+  * Returns -1 if no 1 bit exists
+  */
+-static inline unsigned long __fls(unsigned long word)
++static __always_inline unsigned long __fls(unsigned long word)
+ {
+       int num;
+ 
+@@ -528,7 +528,7 @@ static inline unsigned long __fls(unsign
+  * Returns 0..SZLONG-1
+  * Undefined if no bit exists, so code should check against 0 first.
+  */
+-static inline unsigned long __ffs(unsigned long word)
++static __always_inline unsigned long __ffs(unsigned long word)
+ {
+       return __fls(word & -word);
+ }
+--- a/arch/mips/kernel/cpu-bugs64.c
++++ b/arch/mips/kernel/cpu-bugs64.c
+@@ -42,8 +42,8 @@ static inline void align_mod(const int a
+               : GCC_IMM_ASM() (align), GCC_IMM_ASM() (mod));
+ }
+ 
+-static inline void mult_sh_align_mod(long *v1, long *v2, long *w,
+-                                   const int align, const int mod)
++static __always_inline void mult_sh_align_mod(long *v1, long *v2, long *w,
++                                            const int align, const int mod)
+ {
+       unsigned long flags;
+       int m1, m2;
+--- a/arch/powerpc/kernel/prom_init.c
++++ b/arch/powerpc/kernel/prom_init.c
+@@ -474,14 +474,14 @@ static int __init prom_next_node(phandle
+       }
+ }
+ 
+-static inline int prom_getprop(phandle node, const char *pname,
+-                             void *value, size_t valuelen)
++static inline int __init prom_getprop(phandle node, const char *pname,
++                                    void *value, size_t valuelen)
+ {
+       return call_prom("getprop", 4, 1, node, ADDR(pname),
+                        (u32)(unsigned long) value, (u32) valuelen);
+ }
+ 
+-static inline int prom_getproplen(phandle node, const char *pname)
++static inline int __init prom_getproplen(phandle node, const char *pname)
+ {
+       return call_prom("getproplen", 2, 1, node, ADDR(pname));
+ }
+--- a/arch/s390/include/asm/cpacf.h
++++ b/arch/s390/include/asm/cpacf.h
+@@ -184,7 +184,7 @@ static inline int __cpacf_check_opcode(u
+       }
+ }
+ 
+-static inline int cpacf_query(unsigned int opcode, cpacf_mask_t *mask)
++static __always_inline int cpacf_query(unsigned int opcode, cpacf_mask_t *mask)
+ {
+       if (__cpacf_check_opcode(opcode)) {
+               __cpacf_query(opcode, mask);
 --- a/arch/x86/Kconfig.debug
 +++ b/arch/x86/Kconfig.debug
 @@ -284,20 +284,6 @@ config CPA_DEBUG
@@ -23,13 +118,13 @@
        depends on DEBUG_KERNEL
 --- a/lib/Kconfig.debug
 +++ b/lib/Kconfig.debug
-@@ -137,6 +137,20 @@ endmenu # "printk and dmesg options"
- 
- menu "Compile-time checks and compiler options"
+@@ -305,6 +305,20 @@ config HEADERS_CHECK
+         exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
+         your build tree), to make sure they're suitable.
  
 +config OPTIMIZE_INLINING
-+      bool "Allow gcc to uninline functions marked 'inline'"
-+      ---help---
++      bool "Allow compiler to uninline functions marked 'inline'"
++      help
 +        This option determines if the kernel forces gcc to inline the functions
 +        developers have marked 'inline'. Doing so takes away freedom from gcc to
 +        do what it thinks is best, which is desirable for the gcc 3.x series of
@@ -41,9 +136,9 @@
 +
 +        If unsure, say N.
 +
- config DEBUG_INFO
-       bool "Compile the kernel with debug info"
-       depends on DEBUG_KERNEL && !COMPILE_TEST
+ config DEBUG_SECTION_MISMATCH
+       bool "Enable full Section mismatch analysis"
+       help
 --- a/arch/x86/Kconfig
 +++ b/arch/x86/Kconfig
 @@ -296,9 +296,6 @@ config ZONE_DMA32