Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 12 Apr 2023 19:42:55 +0300
From:   Mike Rapoport <rppt@linux.ibm.com>
To:     Peter Xu <peterx@redhat.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Andrea Arcangeli <aarcange@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nadav Amit <nadav.amit@gmail.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Leonardo Bras Soares Passos <lsoaresp@redhat.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>
Subject: Re: [PATCH 14/29] selftests/mm: uffd_[un]register()
Message-ID: <ZDbfjxFkxKVATjVQ@linux.ibm.com>
References: <20230330155707.3106228-1-peterx@redhat.com>
 <20230330160747.3107258-1-peterx@redhat.com>
 <ZC/5xstCOs8wp6nK@linux.ibm.com>
 <ZDWxTsJUTS1OSjJw@x1n>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <ZDWxTsJUTS1OSjJw@x1n>
Precedence: bulk

On Tue, Apr 11, 2023 at 03:13:18PM -0400, Peter Xu wrote:
> On Fri, Apr 07, 2023 at 02:08:54PM +0300, Mike Rapoport wrote:
> > > @@ -96,11 +95,7 @@ static void register_region_with_uffd(char *addr, size_t len)
> > >  	 * handling by the userfaultfd object. In mode, we request to track
> > >  	 * missing pages (i.e., pages that have not yet been faulted in).
> > >  	 */
> > > -
> > > -	uffdio_register.range.start = (unsigned long)addr;
> > > -	uffdio_register.range.len = len;
> > > -	uffdio_register.mode = UFFDIO_REGISTER_MODE_MISSING;
> > > -	if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) == -1) {
> > > +	if (uffd_register(uffd, addr, len, true, false, false)) {
> > 
> > I'd replace booleans with a bit flags as it easier to read.
> > Other than that LGTM.
> 
> It was mostly for no need to remember the long names of macros, and easier
> when conditionally set with some modes. E.g., we have 5 callers have things
> like:
> 
>   uffd_register(..., test_uffdio_wp ? UFFDIO_REGISTER_MODE_WP : 0);
> 
> The bools simplifes it to:
> 
>   uffd_register(..., test_uffdio_wp, ...);
> 
> But let me know if you still think that's better - I can switch here.

No strong feelings, however you prefer.
 
> Thanks,
> 
> -- 
> Peter Xu
> 

-- 
Sincerely yours,
Mike.