From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id D246F6B02C4 for ; Thu, 11 May 2017 13:41:38 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id q77so7668905wmg.13 for ; Thu, 11 May 2017 10:41:38 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id r28si1330548eda.267.2017.05.11.10.41.36 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 11 May 2017 10:41:37 -0700 (PDT) Date: Thu, 11 May 2017 19:41:28 +0200 From: Borislav Petkov Subject: Re: [RFC 01/10] x86/mm: Reimplement flush_tlb_page() using flush_tlb_mm_range() Message-ID: <20170511174128.rp7dwckpci4gqsxy@pd.tnic> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: X86 ML , "linux-kernel@vger.kernel.org" , Linus Torvalds , Andrew Morton , Mel Gorman , "linux-mm@kvack.org" , Rik van Riel , Dave Hansen , Nadav Amit , Michal Hocko On Sun, May 07, 2017 at 05:38:30AM -0700, Andy Lutomirski wrote: > flush_tlb_page() was very similar to flush_tlb_mm_range() except that > it had a couple of issues: > > - It was missing an smp_mb() in the case where > current->active_mm != mm. (This is a longstanding bug reported by > Nadav Amit.) > > - It was missing tracepoints and vm counter updates. > > The only reason that I can see for keeping it at as a separate > function is that it could avoid a few branches that > flush_tlb_mm_range() needs to decide to flush just one page. This > hardly seems worthwhile. If we decide we want to get rid of those > branches again, a better way would be to introduce an > __flush_tlb_mm_range() helper and make both flush_tlb_page() and > flush_tlb_mm_range() use it. > > Cc: Rik van Riel > Cc: Dave Hansen > Cc: Nadav Amit > Cc: Michal Hocko > Cc: Andrew Morton > Signed-off-by: Andy Lutomirski > --- > arch/x86/include/asm/tlbflush.h | 6 +++++- > arch/x86/mm/tlb.c | 27 --------------------------- > 2 files changed, 5 insertions(+), 28 deletions(-) > > diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h > index 6ed9ea469b48..5ed64cdaf536 100644 > --- a/arch/x86/include/asm/tlbflush.h > +++ b/arch/x86/include/asm/tlbflush.h > @@ -307,11 +307,15 @@ static inline void flush_tlb_kernel_range(unsigned long start, > flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags) > > extern void flush_tlb_all(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); > > +static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) > +{ > + flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, 0); VM_NONE); -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix ImendA?rffer, Jane Smithard, Graham Norton, HRB 21284 (AG NA 1/4 rnberg) -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org