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| author | Borislav Petkov <bp@suse.de> | 2018-07-14 02:26:17 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-17 11:31:44 +0200 |
| commit | 8c9814143e58cc34d29dbf187d0ffe04680e17f9 (patch) | |
| tree | 09acfa025c273135d8599da1b8ca7d74e0a66d9c | |
| parent | 0f66fae5d614efedac967ab010faa3f6bf44a347 (diff) | |
| download | linux-stable-8c9814143e58cc34d29dbf187d0ffe04680e17f9.tar.gz linux-stable-8c9814143e58cc34d29dbf187d0ffe04680e17f9.tar.bz2 linux-stable-8c9814143e58cc34d29dbf187d0ffe04680e17f9.zip | |
x86/cpu: Provide a config option to disable static_cpu_has
commit 6e1315fe82308cd29e7550eab967262e8bbc71a3 upstream
This brings .text savings of about ~1.6K when building a tinyconfig. It
is off by default so nothing changes for the default.
Kconfig help text from Josh.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Link: http://lkml.kernel.org/r/1449481182-27541-5-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/Kconfig | 11 | ||||
| -rw-r--r-- | arch/x86/include/asm/cpufeature.h | 2 |
2 files changed, 12 insertions, 1 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index eab1ef25eecd..d9afe6d40550 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -346,6 +346,17 @@ config X86_FEATURE_NAMES If in doubt, say Y. +config X86_FAST_FEATURE_TESTS + bool "Fast CPU feature tests" if EMBEDDED + default y + ---help--- + Some fast-paths in the kernel depend on the capabilities of the CPU. + Say Y here for the kernel to patch in the appropriate code at runtime + based on the capabilities of the CPU. The infrastructure for patching + code at runtime takes up some additional space; space-constrained + embedded systems may wish to say N here to produce smaller, slightly + slower code. + config X86_X2APIC bool "Support x2apic" depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 54c7a0b9662a..67f917b96651 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -422,7 +422,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; * fast paths and boot_cpu_has() otherwise! */ -#if __GNUC__ >= 4 +#if __GNUC__ >= 4 && defined(CONFIG_X86_FAST_FEATURE_TESTS) extern void warn_pre_alternatives(void); extern bool __static_cpu_has_safe(u16 bit); |