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Groups > linux.kernel > #1295347
| From | tip-bot for Borislav Petkov <tipbot@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [tip:x86/cpufeature] x86/cpu: Provide a config option to disable static_cpu_has |
| Date | 2015-12-19 11:30 +0100 |
| Message-ID | <qHmVY-1VE-11@gated-at.bofh.it> (permalink) |
| References | <qD0AG-2K8-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Commit-ID: a4eb0afca79fd699b33e059f81d204e84f2b6760 Gitweb: http://git.kernel.org/tip/a4eb0afca79fd699b33e059f81d204e84f2b6760 Author: Borislav Petkov <bp@suse.de> AuthorDate: Mon, 7 Dec 2015 10:39:42 +0100 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Sat, 19 Dec 2015 11:14:01 +0100 x86/cpu: Provide a config option to disable static_cpu_has 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> --- arch/x86/Kconfig | 11 +++++++++++ arch/x86/include/asm/cpufeature.h | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index db3622f..a2abc2f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -349,6 +349,17 @@ 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 144b042..43e1444 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -409,7 +409,7 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[tip:x86/cpufeature] x86/cpu: Provide a config option to disable static_cpu_has tip-bot for Borislav Petkov <tipbot@zytor.com> - 2015-12-19 11:30 +0100
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