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Message-ID: <387a6703-b8fb-d2ed-16b1-5264b2c901aa@redhat.com>
Date:   Fri, 6 Oct 2023 14:56:59 +0200
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Subject: Re: [PATCH v2 3/4] mm/gup: make failure to pin an error if
 FOLL_NOWAIT not specified
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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>
 <2a42d96dd1e37163f90a0019a541163dafb7e4c3.1696288092.git.lstoakes@gmail.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <2a42d96dd1e37163f90a0019a541163dafb7e4c3.1696288092.git.lstoakes@gmail.com>
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On 03.10.23 01:14, Lorenzo Stoakes wrote:
> There really should be no circumstances under which a non-FOLL_NOWAIT GUP
> operation fails to return any pages, so make this an error and warn on it.
> 
> To catch the trivial case, simply exit early if nr_pages == 0.
> 
> This brings __get_user_pages_locked() in line with the behaviour of its
> nommu variant.
> 
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
> ---

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

-- 
Cheers,

David / dhildenb