From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id B04D86B0292 for ; Thu, 25 May 2017 21:43:58 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id m5so250336440pfc.1 for ; Thu, 25 May 2017 18:43:58 -0700 (PDT) Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com. [2607:f8b0:400e:c00::244]) by mx.google.com with ESMTPS id p90si29727754pfa.379.2017.05.25.18.43.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 May 2017 18:43:58 -0700 (PDT) Received: by mail-pf0-x244.google.com with SMTP id w69so42543717pfk.1 for ; Thu, 25 May 2017 18:43:58 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: [PATCH v3 2/8] x86/mm: Change the leave_mm() condition for local TLB flushes From: Nadav Amit In-Reply-To: <61de238db6d9c9018db020c41047ce32dac64488.1495759610.git.luto@kernel.org> Date: Thu, 25 May 2017 18:43:55 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: References: <61de238db6d9c9018db020c41047ce32dac64488.1495759610.git.luto@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: X86 ML , "linux-kernel@vger.kernel.org" , Borislav Petkov , Linus Torvalds , Andrew Morton , Mel Gorman , "linux-mm@kvack.org" , Rik van Riel , Dave Hansen , Nadav Amit , Michal Hocko , Arjan van de Ven > On May 25, 2017, at 5:47 PM, Andy Lutomirski wrote: >=20 > On a remote TLB flush, we leave_mm() if we're TLBSTATE_LAZY. For a > local flush_tlb_mm_range(), we leave_mm() if !current->mm. These > are approximately the same condition -- the scheduler sets lazy TLB > mode when switching to a thread with no mm. >=20 > I'm about to merge the local and remote flush code, but for ease of > verifying and bisecting the patch, I want the local and remote flush > behavior to match first. This patch changes the local code to match > the remote code. >=20 > Cc: Rik van Riel > Cc: Dave Hansen > Cc: Nadav Amit > Cc: Michal Hocko > Cc: Arjan van de Ven > Signed-off-by: Andy Lutomirski > --- > arch/x86/mm/tlb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c > index 776469cc54e0..3143c9a180e5 100644 > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -311,7 +311,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, = unsigned long start, > goto out; > } >=20 > - if (!current->mm) { > + if (this_cpu_read(cpu_tlbstate.state) !=3D TLBSTATE_OK) { > leave_mm(smp_processor_id()); Maybe it is an overkill, but you may want to have two variants: = leave_mm() and leave_mm_irq_off(). Currently, leave_mm() does not disable IRQs, but in patch 6 it does. Here you indeed need to disable IRQs, but the cases in prior to this patch - you do not. -- 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