[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 <ak@suse.de>
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 8564b6a..ad91528 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -67,11 +67,17 @@
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 @@
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 @@
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 2316725..4c83e05 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 */