Commit 60a3cdd06394 ("x86: add optimized inlining") introduced CONFIG_OPTIMIZE_INLINING, but it has been available only for x86. The idea is obviously arch-agnostic although we need some code fixups. This commit moves the config entry from arch/x86/Kconfig.debug to lib/Kconfig.debug so that all architectures (except MIPS for now) can benefit from it. At this moment, I added "depends on !MIPS" because fixing 0day bot reports for MIPS was complex to me. I tested this patch on my arm/arm64 boards. This can make a huge difference in kernel image size especially when CONFIG_OPTIMIZE_FOR_SIZE is enabled. For example, I got 3.5% smaller arm64 kernel image for v5.1-rc1. dec file 18983424 arch/arm64/boot/Image.before 18321920 arch/arm64/boot/Image.after This also slightly improves the "Kernel hacking" Kconfig menu. Commit e61aca5158a8 ("Merge branch 'kconfig-diet' from Dave Hansen') mentioned this config option would be a good fit in the "compiler option" menu. I did so. I fixed up some files to avoid build warnings/errors. [1] arch/arm64/include/asm/cpufeature.h In file included from ././include/linux/compiler_types.h:68, from <command-line>: ./arch/arm64/include/asm/jump_label.h: In function 'cpus_have_const_cap': ./include/linux/compiler-gcc.h:120:38: warning: asm operand 0 probably doesn't match constraints #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) ^~~ ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro 'asm_volatile_goto' asm_volatile_goto( ^~~~~~~~~~~~~~~~~ ./include/linux/compiler-gcc.h:120:38: error: impossible constraint in 'asm' #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0) ^~~ ./arch/arm64/include/asm/jump_label.h:32:2: note: in expansion of macro 'asm_volatile_goto' asm_volatile_goto( ^~~~~~~~~~~~~~~~~ [2] arch/mips/kernel/cpu-bugs64.c arch/mips/kernel/cpu-bugs64.c: In function 'mult_sh_align_mod.constprop': arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't match constraints [-Werror] asm volatile( ^~~ arch/mips/kernel/cpu-bugs64.c:33:2: error: asm operand 1 probably doesn't match constraints [-Werror] asm volatile( ^~~ arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm' asm volatile( ^~~ arch/mips/kernel/cpu-bugs64.c:33:2: error: impossible constraint in 'asm' asm volatile( ^~~ [3] arch/powerpc/mm/tlb-radix.c arch/powerpc/mm/tlb-radix.c: In function '__radix__flush_tlb_range_psize': arch/powerpc/mm/tlb-radix.c:104:2: error: asm operand 3 probably doesn't match constraints [-Werror] asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1) ^~~ arch/powerpc/mm/tlb-radix.c:104:2: error: impossible constraint in 'asm' CC arch/powerpc/perf/hv-gpci.o [4] arch/s390/include/asm/cpacf.h In file included from arch/s390/crypto/des_s390.c:19: ./arch/s390/include/asm/cpacf.h: In function 'cpacf_query': ./arch/s390/include/asm/cpacf.h:170:2: warning: asm operand 3 probably doesn't match constraints asm volatile( ^~~ ./arch/s390/include/asm/cpacf.h:170:2: error: impossible constraint in 'asm' [5] arch/powerpc/kernel/prom_init.c WARNING: vmlinux.o(.text.unlikely+0x20): Section mismatch in reference from the function .prom_getprop() to the function .init.text:.call_prom() The function .prom_getprop() references the function __init .call_prom(). This is often because .prom_getprop lacks a __init annotation or the annotation of .call_prom is wrong. WARNING: vmlinux.o(.text.unlikely+0x3c): Section mismatch in reference from the function .prom_getproplen() to the function .init.text:.call_prom() The function .prom_getproplen() references the function __init .call_prom(). This is often because .prom_getproplen lacks a __init annotation or the annotation of .call_prom is wrong. [6] drivers/mtd/nand/raw/vf610_nfc.c drivers/mtd/nand/raw/vf610_nfc.c: In function ‘vf610_nfc_cmd’: drivers/mtd/nand/raw/vf610_nfc.c:455:3: warning: ‘offset’ may be used uninitialized in this function [-Wmaybe-uninitialized] vf610_nfc_rd_from_sram(instr->ctx.data.buf.in + offset, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ nfc->regs + NFC_MAIN_AREA(0) + offset, ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ trfr_sz, !nfc->data_access); ~~~~~~~~~~~~~~~~~~~~~~~~~~~ [7] arch/arm/kernel/smp.c arch/arm/kernel/smp.c: In function ‘raise_nmi’: arch/arm/kernel/smp.c:522:2: warning: array subscript is above array bounds [-Warray-bounds] trace_ipi_raise_rcuidle(target, ipi_types[ipinr]); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The fixup is not included in this. The patch is available in ML: http://lists.infradead.org/pipermail/linux-arm-kernel/2016-February/409393.html Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- arch/arm64/include/asm/cpufeature.h | 4 ++-- arch/mips/kernel/cpu-bugs64.c | 4 ++-- arch/powerpc/kernel/prom_init.c | 6 +++--- arch/powerpc/mm/tlb-radix.c | 2 +- arch/s390/include/asm/cpacf.h | 2 +- arch/x86/Kconfig | 3 --- arch/x86/Kconfig.debug | 14 -------------- drivers/mtd/nand/raw/vf610_nfc.c | 2 +- include/linux/compiler_types.h | 3 +-- lib/Kconfig.debug | 15 +++++++++++++++ 10 files changed, 26 insertions(+), 29 deletions(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index e505e1f..77d1aa5 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -406,7 +406,7 @@ static inline bool cpu_have_feature(unsigned int num) } /* 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; @@ -420,7 +420,7 @@ static inline bool cpus_have_cap(unsigned int num) 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); diff --git a/arch/mips/kernel/cpu-bugs64.c b/arch/mips/kernel/cpu-bugs64.c index bada74a..c04b97a 100644 --- 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 align, const int mod) : "n"(align), "n"(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; diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index f33ff41..241fe6b 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -501,14 +501,14 @@ static int __init prom_next_node(phandle *nodep) } } -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)); } diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index 6a23b9e..a2b2848 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -928,7 +928,7 @@ void radix__tlb_flush(struct mmu_gather *tlb) tlb->need_flush_all = 0; } -static inline void __radix__flush_tlb_range_psize(struct mm_struct *mm, +static __always_inline void __radix__flush_tlb_range_psize(struct mm_struct *mm, unsigned long start, unsigned long end, int psize, bool also_pwc) { diff --git a/arch/s390/include/asm/cpacf.h b/arch/s390/include/asm/cpacf.h index 3cc52e3..f316de4 100644 --- a/arch/s390/include/asm/cpacf.h +++ b/arch/s390/include/asm/cpacf.h @@ -202,7 +202,7 @@ static inline int __cpacf_check_opcode(unsigned int opcode) } } -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); diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c1f9b3c..1a3e2b5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -310,9 +310,6 @@ config ZONE_DMA32 config AUDIT_ARCH def_bool y if X86_64 -config ARCH_SUPPORTS_OPTIMIZED_INLINING - def_bool y - config ARCH_SUPPORTS_DEBUG_PAGEALLOC def_bool y diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 15d0fbe..f730680 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -266,20 +266,6 @@ config CPA_DEBUG ---help--- Do change_page_attr() self-tests every 30 seconds. -config OPTIMIZE_INLINING - bool "Allow gcc 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 - compilers. The gcc 4.x series have a rewritten inlining algorithm and - enabling this option will generate a smaller kernel there. Hopefully - this algorithm is so good that allowing gcc 4.x and above to make the - decision will become the default in the future. Until then this option - is there to test gcc for this. - - If unsure, say N. - config DEBUG_ENTRY bool "Debug low-level entry code" depends on DEBUG_KERNEL diff --git a/drivers/mtd/nand/raw/vf610_nfc.c b/drivers/mtd/nand/raw/vf610_nfc.c index a662ca1..19792d7 100644 --- a/drivers/mtd/nand/raw/vf610_nfc.c +++ b/drivers/mtd/nand/raw/vf610_nfc.c @@ -364,7 +364,7 @@ static int vf610_nfc_cmd(struct nand_chip *chip, { const struct nand_op_instr *instr; struct vf610_nfc *nfc = chip_to_nfc(chip); - int op_id = -1, trfr_sz = 0, offset; + int op_id = -1, trfr_sz = 0, offset = 0; u32 col = 0, row = 0, cmd1 = 0, cmd2 = 0, code = 0; bool force8bit = false; diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index ba814f1..19e58b9 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -140,8 +140,7 @@ struct ftrace_likely_data { * Do not use __always_inline here, since currently it expands to inline again * (which would break users of __always_inline). */ -#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \ - !defined(CONFIG_OPTIMIZE_INLINING) +#if !defined(CONFIG_OPTIMIZE_INLINING) #define inline inline __attribute__((__always_inline__)) __gnu_inline \ __maybe_unused notrace #else diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0d9e817..20f3dfc 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -310,6 +310,21 @@ 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 compiler to uninline functions marked 'inline'" + depends on !MIPS # TODO: look into MIPS code + 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 + compilers. The gcc 4.x series have a rewritten inlining algorithm and + enabling this option will generate a smaller kernel there. Hopefully + this algorithm is so good that allowing gcc 4.x and above to make the + decision will become the default in the future. Until then this option + is there to test gcc for this. + + If unsure, say N. + config DEBUG_SECTION_MISMATCH bool "Enable full Section mismatch analysis" help -- 2.7.4