From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756764Ab2F1BFo (ORCPT ); Wed, 27 Jun 2012 21:05:44 -0400 Received: from mga09.intel.com ([134.134.136.24]:12305 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932282Ab2F1BFm (ORCPT ); Wed, 27 Jun 2012 21:05:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="159020486" From: Alex Shi To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, rostedt@goodmis.org, fweisbec@gmail.com Cc: jeremy@goop.org, alex.shi@intel.com, luto@mit.edu, yinghai@kernel.org, riel@redhat.com, avi@redhat.com, len.brown@intel.com, tj@kernel.org, akpm@linux-foundation.org, cl@gentwo.org, borislav.petkov@amd.com, ak@linux.intel.com, jbeulich@suse.com, eric.dumazet@gmail.com, akinobu.mita@gmail.com, vapier@gentoo.org, cpw@sgi.com, steiner@sgi.com, viro@zeniv.linux.org.uk, kamezawa.hiroyu@jp.fujitsu.com, rientjes@google.com, aarcange@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH v10 9/9] x86/tlb: do flush_tlb_kernel_range by 'invlpg' Date: Thu, 28 Jun 2012 09:02:24 +0800 Message-Id: <1340845344-27557-10-git-send-email-alex.shi@intel.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1340845344-27557-1-git-send-email-alex.shi@intel.com> References: <1340845344-27557-1-git-send-email-alex.shi@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch do flush_tlb_kernel_range by 'invlpg'. The performance pay and gain was analyzed in previous patch (x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range). In the testing: http://lkml.org/lkml/2012/6/21/10 The pay is mostly covered by long kernel path, but the gain is still quite clear, memory access in user APP can increase 30+% when kernel execute this funtion. Signed-off-by: Alex Shi --- arch/x86/include/asm/tlbflush.h | 13 +++++++------ arch/x86/mm/tlb.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 621b959..b5a27bd 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -123,6 +123,12 @@ static inline void reset_lazy_tlbstate(void) { } +static inline void flush_tlb_kernel_range(unsigned long start, + unsigned long end) +{ + flush_tlb_all(); +} + #else /* SMP */ #include @@ -139,6 +145,7 @@ extern void flush_tlb_current_task(void); extern void flush_tlb_page(struct vm_area_struct *, unsigned long); extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, unsigned long end, unsigned long vmflag); +extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); #define flush_tlb() flush_tlb_current_task() @@ -168,10 +175,4 @@ static inline void reset_lazy_tlbstate(void) native_flush_tlb_others(mask, mm, start, end) #endif -static inline void flush_tlb_kernel_range(unsigned long start, - unsigned long end) -{ - flush_tlb_all(); -} - #endif /* _ASM_X86_TLBFLUSH_H */ diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 2b5f506..613cd83 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -264,6 +264,36 @@ void flush_tlb_all(void) on_each_cpu(do_flush_tlb_all, NULL, 1); } +static void do_kernel_range_flush(void *info) +{ + struct flush_tlb_info *f = info; + unsigned long addr; + + /* flush range by one by one 'invlpg' */ + for (addr = f->flush_start; addr < f->flush_end; addr += PAGE_SIZE) + __flush_tlb_single(addr); +} + +void flush_tlb_kernel_range(unsigned long start, unsigned long end) +{ + unsigned act_entries; + struct flush_tlb_info info; + + /* In modern CPU, last level tlb used for both data/ins */ + act_entries = tlb_lld_4k[ENTRIES]; + + /* Balance as user space task's flush, a bit conservative */ + if (end == TLB_FLUSH_ALL || tlb_flushall_shift == -1 || + (end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift) + + on_each_cpu(do_flush_tlb_all, NULL, 1); + else { + info.flush_start = start; + info.flush_end = end; + on_each_cpu(do_kernel_range_flush, &info, 1); + } +} + #ifdef CONFIG_DEBUG_TLBFLUSH static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) -- 1.7.5.4