Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753565Ab3IQRAi (ORCPT ); Tue, 17 Sep 2013 13:00:38 -0400 Received: from cantor2.suse.de ([195.135.220.15]:35792 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752881Ab3IQRAh (ORCPT ); Tue, 17 Sep 2013 13:00:37 -0400 Date: Tue, 17 Sep 2013 18:00:32 +0100 From: Mel Gorman To: Peter Zijlstra Cc: Rik van Riel , Srikar Dronamraju , Ingo Molnar , Andrea Arcangeli , Johannes Weiner , Linux-MM , LKML Subject: Re: [PATCH 17/50] mm: Do not flush TLB during protection change if !pte_present && !migration_entry Message-ID: <20130917170031.GM22421@suse.de> References: <1378805550-29949-1-git-send-email-mgorman@suse.de> <1378805550-29949-18-git-send-email-mgorman@suse.de> <20130916163547.GF9326@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20130916163547.GF9326@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1586 Lines: 43 On Mon, Sep 16, 2013 at 06:35:47PM +0200, Peter Zijlstra wrote: > On Tue, Sep 10, 2013 at 10:31:57AM +0100, Mel Gorman wrote: > > NUMA PTE scanning is expensive both in terms of the scanning itself and > > the TLB flush if there are any updates. Currently non-present PTEs are > > accounted for as an update and incurring a TLB flush where it is only > > necessary for anonymous migration entries. This patch addresses the > > problem and should reduce TLB flushes. > > > > Signed-off-by: Mel Gorman > > --- > > mm/mprotect.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/mm/mprotect.c b/mm/mprotect.c > > index 1f9b54b..1e9cef0 100644 > > --- a/mm/mprotect.c > > +++ b/mm/mprotect.c > > @@ -109,8 +109,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, > > make_migration_entry_read(&entry); > > set_pte_at(mm, addr, pte, > > swp_entry_to_pte(entry)); > > + > > + pages++; > > } > > - pages++; > > } > > } while (pte++, addr += PAGE_SIZE, addr != end); > > arch_leave_lazy_mmu_mode(); > > Should we fold this into patch 7 ? Looking closer at it, I think folding it into the patch would overload the purpose of patch 7 a little too much but I shuffled the series to keep the patches together. -- Mel Gorman SUSE Labs -- 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/