From: Thomas Gleixner Date: Wed, 30 Jan 2008 12:34:08 +0000 (+0100) Subject: x86: optimize clflush X-Git-Tag: v2.6.25-rc1~1143^2~32 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3b233e52f70bf102078b2c0c3f7f86a441689056;p=linux-2.6 x86: optimize clflush clflush is sufficient to be issued on one CPU. The invalidation is broadcast throughout the coherence domain. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 90b658ac39..bbfc8e2466 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -64,35 +64,29 @@ static void cpa_flush_all(void) on_each_cpu(__cpa_flush_all, NULL, 1, 1); } -struct clflush_data { - unsigned long addr; - int numpages; -}; - static void __cpa_flush_range(void *arg) { - struct clflush_data *cld = arg; - /* * We could optimize that further and do individual per page * tlb invalidates for a low number of pages. Caveat: we must * flush the high aliases on 64bit as well. */ __flush_tlb_all(); - - clflush_cache_range((void *) cld->addr, cld->numpages * PAGE_SIZE); } static void cpa_flush_range(unsigned long addr, int numpages) { - struct clflush_data cld; - BUG_ON(irqs_disabled()); - cld.addr = addr; - cld.numpages = numpages; + on_each_cpu(__cpa_flush_range, NULL, 1, 1); - on_each_cpu(__cpa_flush_range, &cld, 1, 1); + /* + * We only need to flush on one CPU, + * clflush is a MESI-coherent instruction that + * will cause all other CPUs to flush the same + * cachelines: + */ + clflush_cache_range((void *) addr, numpages * PAGE_SIZE); } /*