Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33;
Message-ID: <4131ade7-c790-053c-99cb-3544f3c6523d@redhat.com>
Date:   Fri, 6 Oct 2023 14:57:35 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH v2 4/4] mm/gup: adapt get_user_page_vma_remote() to never
 return NULL
Content-Language: en-US
To:     Lorenzo Stoakes <lstoakes@gmail.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>
Cc:     Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Richard Cochran <richardcochran@gmail.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Arnd Bergmann <arnd@arndb.de>
References: <cover.1696288092.git.lstoakes@gmail.com>
 <00319ce292d27b3aae76a0eb220ce3f528187508.1696288092.git.lstoakes@gmail.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <00319ce292d27b3aae76a0eb220ce3f528187508.1696288092.git.lstoakes@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 03.10.23 01:14, Lorenzo Stoakes wrote:
> get_user_pages_remote() will never return 0 except in the case of
> FOLL_NOWAIT being specified, which we explicitly disallow.
> 
> This simplifies error handling for the caller and avoids the awkwardness of
> dealing with both errors and failing to pin. Failing to pin here is an
> error.
> 
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
> ---

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb