Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of... (f02a38d8) · Commits · 戴 / test

arch/Kconfig

+14 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,20 @@ config KPROBES
		for kernel debugging, non-intrusive instrumentation and testing.
		If in doubt, say "N".

		config JUMP_LABEL
		bool "Optimize trace point call sites"
		depends on HAVE_ARCH_JUMP_LABEL
		help
		If it is detected that the compiler has support for "asm goto",
		the kernel will compile trace point locations with just a
		nop instruction. When trace points are enabled, the nop will
		be converted to a jump to the trace function. This technique
		lowers overhead and stress on the branch prediction of the
		processor.

		On i386, options added to the compiler flags may increase
		the size of the kernel slightly.

		config OPTPROBES
		def_bool y
		depends on KPROBES && HAVE_OPTPROBES

arch/sparc/include/asm/jump_label.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@
		"nop\n\t" \
		"nop\n\t" \
		".pushsection __jump_table, \"a\"\n\t"\
		".align 4\n\t" \
		".word 1b, %l[" #label "], %c0\n\t" \
		".popsection \n\t" \
		: : "i" (key) : : label);\

arch/x86/Makefile_32.cpu

+12 −1

Original line number	Diff line number	Diff line
		@@ -51,7 +51,18 @@ cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686))
		# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph
		# tracer assumptions. For i686, generic, core2 this is set by the
		# compiler anyway
		cflags-$(CONFIG_FUNCTION_GRAPH_TRACER) += $(call cc-option,-maccumulate-outgoing-args)
		ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y)
		ADD_ACCUMULATE_OUTGOING_ARGS := y
		endif

		# Work around to a bug with asm goto with first implementations of it
		# in gcc causing gcc to mess up the push and pop of the stack in some
		# uses of asm goto.
		ifeq ($(CONFIG_JUMP_LABEL), y)
		ADD_ACCUMULATE_OUTGOING_ARGS := y
		endif

		cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args)

		# Bug fix for binutils: this option is required in order to keep
		# binutils from generating NOPL instructions against our will.

arch/x86/kernel/alternative.c

+15 −54

Original line number	Diff line number	Diff line
		@@ -644,65 +644,26 @@ void __kprobes text_poke_smp(void addr, const void *opcode, size_t len)

		#if defined(CONFIG_DYNAMIC_FTRACE) \|\| defined(HAVE_JUMP_LABEL)

		unsigned char ideal_nop5[IDEAL_NOP_SIZE_5];
		#ifdef CONFIG_X86_64
		unsigned char ideal_nop5[5] = { 0x66, 0x66, 0x66, 0x66, 0x90 };
		#else
		unsigned char ideal_nop5[5] = { 0x3e, 0x8d, 0x74, 0x26, 0x00 };
		#endif

		void __init arch_init_ideal_nop5(void)
		{
		extern const unsigned char ftrace_test_p6nop[];
		extern const unsigned char ftrace_test_nop5[];
		extern const unsigned char ftrace_test_jmp[];
		int faulted = 0;

		/*
		* There is no good nop for all x86 archs.
		* We will default to using the P6_NOP5, but first we
		* will test to make sure that the nop will actually
		* work on this CPU. If it faults, we will then
		* go to a lesser efficient 5 byte nop. If that fails
		* we then just use a jmp as our nop. This isn't the most
		* efficient nop, but we can not use a multi part nop
		* since we would then risk being preempted in the middle
		* of that nop, and if we enabled tracing then, it might
		* cause a system crash.
		* There is no good nop for all x86 archs. This selection
		* algorithm should be unified with the one in find_nop_table(),
		* but this should be good enough for now.
		*
		* TODO: check the cpuid to determine the best nop.
		* For cases other than the ones below, use the safe (as in
		* always functional) defaults above.
		*/
		asm volatile (
		"ftrace_test_jmp:"
		"jmp ftrace_test_p6nop\n"
		"nop\n"
		"nop\n"
		"nop\n" /* 2 byte jmp + 3 bytes */
		"ftrace_test_p6nop:"
		P6_NOP5
		"jmp 1f\n"
		"ftrace_test_nop5:"
		".byte 0x66,0x66,0x66,0x66,0x90\n"
		"1:"
		".section .fixup, \"ax\"\n"
		"2: movl $1, %0\n"
		" jmp ftrace_test_nop5\n"
		"3: movl $2, %0\n"
		" jmp 1b\n"
		".previous\n"
		_ASM_EXTABLE(ftrace_test_p6nop, 2b)
		_ASM_EXTABLE(ftrace_test_nop5, 3b)
		: "=r"(faulted) : "0" (faulted));

		switch (faulted) {
		case 0:
		pr_info("converting mcount calls to 0f 1f 44 00 00\n");
		memcpy(ideal_nop5, ftrace_test_p6nop, IDEAL_NOP_SIZE_5);
		break;
		case 1:
		pr_info("converting mcount calls to 66 66 66 66 90\n");
		memcpy(ideal_nop5, ftrace_test_nop5, IDEAL_NOP_SIZE_5);
		break;
		case 2:
		pr_info("converting mcount calls to jmp . + 5\n");
		memcpy(ideal_nop5, ftrace_test_jmp, IDEAL_NOP_SIZE_5);
		break;
		}

		#ifdef CONFIG_X86_64
		/* Don't use these on 32 bits due to broken virtualizers */
		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
		memcpy(ideal_nop5, p6_nops[5], 5);
		#endif
		}
		#endif

arch/x86/kernel/apic/io_apic.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3109,7 +3109,7 @@ void destroy_irq(unsigned int irq)

		irq_set_status_flags(irq, IRQ_NOREQUEST\|IRQ_NOPROBE);

		if (intr_remapping_enabled)
		if (irq_remapped(cfg))
		free_irte(irq);
		raw_spin_lock_irqsave(&vector_lock, flags);
		__clear_irq_vector(irq, cfg);

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