From 3760dd6efa75c98e223643da2eb7040406433053 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 7 Dec 2006 02:14:05 +0100 Subject: [PATCH] [PATCH] i386: Use CLFLUSH instead of WBINVD in change_page_attr CLFLUSH is a lot faster than WBINVD so try to use that. Signed-off-by: Andi Kleen --- arch/i386/mm/pageattr.c | 24 +++++++++++++++++------- include/asm-i386/cpufeature.h | 1 + 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c index 8564b6ae17..ad91528bdc 100644 --- a/arch/i386/mm/pageattr.c +++ b/arch/i386/mm/pageattr.c @@ -67,11 +67,17 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot, return base; } -static void flush_kernel_map(void *dummy) +static void flush_kernel_map(void *arg) { - /* Could use CLFLUSH here if the CPU supports it (Hammer,P4) */ - if (boot_cpu_data.x86_model >= 4) + unsigned long adr = (unsigned long)arg; + + if (adr && cpu_has_clflush) { + int i; + for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size) + asm volatile("clflush (%0)" :: "r" (adr + i)); + } else if (boot_cpu_data.x86_model >= 4) wbinvd(); + /* Flush all to work around Errata in early athlons regarding * large page flushing. */ @@ -173,9 +179,9 @@ __change_page_attr(struct page *page, pgprot_t prot) return 0; } -static inline void flush_map(void) +static inline void flush_map(void *adr) { - on_each_cpu(flush_kernel_map, NULL, 1, 1); + on_each_cpu(flush_kernel_map, adr, 1, 1); } /* @@ -217,9 +223,13 @@ void global_flush_tlb(void) spin_lock_irq(&cpa_lock); list_replace_init(&df_list, &l); spin_unlock_irq(&cpa_lock); - flush_map(); - list_for_each_entry_safe(pg, next, &l, lru) + if (!cpu_has_clflush) + flush_map(0); + list_for_each_entry_safe(pg, next, &l, lru) { + if (cpu_has_clflush) + flush_map(page_address(pg)); __free_page(pg); + } } #ifdef CONFIG_DEBUG_PAGEALLOC diff --git a/include/asm-i386/cpufeature.h b/include/asm-i386/cpufeature.h index 231672558c..4c83e05922 100644 --- a/include/asm-i386/cpufeature.h +++ b/include/asm-i386/cpufeature.h @@ -137,6 +137,7 @@ #define cpu_has_pmm_enabled boot_cpu_has(X86_FEATURE_PMM_EN) #define cpu_has_ds boot_cpu_has(X86_FEATURE_DS) #define cpu_has_pebs boot_cpu_has(X86_FEATURE_PEBS) +#define cpu_has_clflush boot_cpu_has(X86_FEATURE_CLFLSH) #endif /* __ASM_I386_CPUFEATURE_H */ -- 2.39.2