diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-process-Optimize-TIF_NOTSC-switch.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-process-Optimize-TIF_NOTSC-switch.patch | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-process-Optimize-TIF_NOTSC-switch.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-process-Optimize-TIF_NOTSC-switch.patch deleted file mode 100644 index e5a210ab..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0037-x86-process-Optimize-TIF_NOTSC-switch.patch +++ /dev/null @@ -1,112 +0,0 @@ -From b72b69b9696975c9279441e4998ceca506280dec Mon Sep 17 00:00:00 2001 -From: Thomas Gleixner <tglx@linutronix.de> -Date: Tue, 14 Feb 2017 00:11:04 -0800 -Subject: [PATCH 37/93] x86/process: Optimize TIF_NOTSC switch - -commit 5a920155e388ec22a22e0532fb695b9215c9b34d upstream - -Provide and use a toggle helper instead of doing it with a branch. - -x86_64: arch/x86/kernel/process.o -text data bss dec hex -3008 8577 16 11601 2d51 Before -2976 8577 16 11569 2d31 After - -i386: arch/x86/kernel/process.o -text data bss dec hex -2925 8673 8 11606 2d56 Before -2893 8673 8 11574 2d36 After - -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Cc: Peter Zijlstra <peterz@infradead.org> -Cc: Andy Lutomirski <luto@kernel.org> -Link: http://lkml.kernel.org/r/20170214081104.9244-4-khuey@kylehuey.com -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - arch/x86/include/asm/tlbflush.h | 10 ++++++++++ - arch/x86/kernel/process.c | 22 ++++------------------ - 2 files changed, 14 insertions(+), 18 deletions(-) - -diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h -index 99185a0..686a58d 100644 ---- a/arch/x86/include/asm/tlbflush.h -+++ b/arch/x86/include/asm/tlbflush.h -@@ -111,6 +111,16 @@ static inline void cr4_clear_bits(unsigned long mask) - } - } - -+static inline void cr4_toggle_bits(unsigned long mask) -+{ -+ unsigned long cr4; -+ -+ cr4 = this_cpu_read(cpu_tlbstate.cr4); -+ cr4 ^= mask; -+ this_cpu_write(cpu_tlbstate.cr4, cr4); -+ __write_cr4(cr4); -+} -+ - /* Read the CR4 shadow. */ - static inline unsigned long cr4_read_shadow(void) - { -diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c -index 496eef6..b7e3822 100644 ---- a/arch/x86/kernel/process.c -+++ b/arch/x86/kernel/process.c -@@ -134,11 +134,6 @@ void flush_thread(void) - fpu__clear(&tsk->thread.fpu); - } - --static void hard_disable_TSC(void) --{ -- cr4_set_bits(X86_CR4_TSD); --} -- - void disable_TSC(void) - { - preempt_disable(); -@@ -147,15 +142,10 @@ void disable_TSC(void) - * Must flip the CPU state synchronously with - * TIF_NOTSC in the current running context. - */ -- hard_disable_TSC(); -+ cr4_set_bits(X86_CR4_TSD); - preempt_enable(); - } - --static void hard_enable_TSC(void) --{ -- cr4_clear_bits(X86_CR4_TSD); --} -- - static void enable_TSC(void) - { - preempt_disable(); -@@ -164,7 +154,7 @@ static void enable_TSC(void) - * Must flip the CPU state synchronously with - * TIF_NOTSC in the current running context. - */ -- hard_enable_TSC(); -+ cr4_clear_bits(X86_CR4_TSD); - preempt_enable(); - } - -@@ -238,12 +228,8 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, - wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); - } - -- if ((tifp ^ tifn) & _TIF_NOTSC) { -- if (tifn & _TIF_NOTSC) -- hard_disable_TSC(); -- else -- hard_enable_TSC(); -- } -+ if ((tifp ^ tifn) & _TIF_NOTSC) -+ cr4_toggle_bits(X86_CR4_TSD); - } - - /* --- -2.7.4 - |