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[209.85.220.65]) by mx.google.com with SMTPS id g20sor1875239ljk.28.2019.06.07.12.28.44 for (Google Transport Security); Fri, 07 Jun 2019 12:28:45 -0700 (PDT) Received-SPF: pass (google.com: domain of jrdr.linux@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b="Yx6/1xCl"; spf=pass (google.com: domain of jrdr.linux@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=jrdr.linux@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=jlRPeDHi0azRjVmRRuBjAHPXJeSQOwNdzPjbtxE4i9M=; b=Yx6/1xClyrNGnGwCp4vb40gTIiQEiT7t05SlLTqVZcMEQhYlLSI8rZkhaccouoWuKt 3KTwRnenBAzMekmve3HaSZM1Xxhy1STO3OyDhj3uxF+wjNs8B7DJMTYfTkqju+4RKqh+ xS0GZHyZIdPcosGREWWk4ZAguMzFHhg8ogolkfeX/XsdavqASaLQVF6WxJahTwwU9SPO ovDhj5ekAjKE0M/nJ/eC4dTZueY1h1oaCt2Dd2lCEHM47gqwel4ftYl8BhG9TgmQIHNt 51fuNGW4m1K513Xd4gzA0q4C9VpoetO6p5VPZ5VkW1b2UdijJhit9lw9g1psUWCXcYGs lFng== X-Google-Smtp-Source: APXvYqx0qKprLQ87qlAbjtmXQEdXhJ8KkH2DSH0IxBEmNEYteKaq5Dm3xiR623NTFVEHjgmvhg0VhLekU5O8P34Ripw= X-Received: by 2002:a2e:9747:: with SMTP id f7mr27943424ljj.34.1559935724712; Fri, 07 Jun 2019 12:28:44 -0700 (PDT) MIME-Version: 1.0 References: <20190523153436.19102-1-jgg@ziepe.ca> <20190523153436.19102-9-jgg@ziepe.ca> In-Reply-To: <20190523153436.19102-9-jgg@ziepe.ca> From: Souptick Joarder Date: Sat, 8 Jun 2019 01:03:48 +0530 Message-ID: Subject: Re: [RFC PATCH 08/11] mm/hmm: Use lockdep instead of comments To: Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, Linux-MM , Jerome Glisse , Ralph Campbell , John Hubbard , Jason Gunthorpe Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, May 23, 2019 at 9:05 PM Jason Gunthorpe wrote: > > From: Jason Gunthorpe > > So we can check locking at runtime. > > Signed-off-by: Jason Gunthorpe > --- > mm/hmm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/hmm.c b/mm/hmm.c > index 2695925c0c5927..46872306f922bb 100644 > --- a/mm/hmm.c > +++ b/mm/hmm.c > @@ -256,11 +256,11 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops = { > * > * To start mirroring a process address space, the device driver must register > * an HMM mirror struct. > - * > - * THE mm->mmap_sem MUST BE HELD IN WRITE MODE ! > */ > int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm) > { > + lockdep_assert_held_exclusive(mm->mmap_sem); > + Gentle query, does the same required in hmm_mirror_unregister() ? > /* Sanity check */ > if (!mm || !mirror || !mirror->ops) > return -EINVAL; > -- > 2.21.0 >