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Message-ID: <f8463381-2697-49e9-9460-9dc73452830d@arm.com>
Date:   Thu, 2 Nov 2023 11:45:37 +0000
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Subject: Re: [PATCH v33 6/6] selftests: mm: add pagemap ioctl tests
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To:     Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Peter Xu <peterx@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <emmir@google.com>,
        Andrei Vagin <avagin@gmail.com>,
        Danylo Mocherniuk <mdanylo@google.com>,
        Paul Gofman <pgofman@codeweavers.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Shuah Khan <shuah@kernel.org>,
        Christian Brauner <brauner@kernel.org>,
        Yang Shi <shy828301@gmail.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Liam R . Howlett" <Liam.Howlett@Oracle.com>,
        Yun Zhou <yun.zhou@windriver.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Alex Sierra <alex.sierra@amd.com>,
        Matthew Wilcox <willy@infradead.org>,
        Pasha Tatashin <pasha.tatashin@soleen.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        "Gustavo A . R . Silva" <gustavoars@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
        Greg KH <gregkh@linuxfoundation.org>, kernel@collabora.com,
        Cyrill Gorcunov <gorcunov@gmail.com>,
        Mike Rapoport <rppt@kernel.org>, Nadav Amit <namit@vmware.com>,
        David Hildenbrand <david@redhat.com>
References: <20230821141518.870589-1-usama.anjum@collabora.com>
 <20230821141518.870589-7-usama.anjum@collabora.com>
From:   Ryan Roberts <ryan.roberts@arm.com>
In-Reply-To: <20230821141518.870589-7-usama.anjum@collabora.com>
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On 21/08/2023 15:15, Muhammad Usama Anjum wrote:

[...]

> +
> +
> +int init_uffd(void)
> +{
> +	struct uffdio_api uffdio_api;
> +
> +	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
> +	if (uffd == -1)
> +		ksft_exit_fail_msg("uffd syscall failed\n");
> +
> +	uffdio_api.api = UFFD_API;
> +	uffdio_api.features = UFFD_FEATURE_WP_UNPOPULATED | UFFD_FEATURE_WP_ASYNC |
> +			      UFFD_FEATURE_WP_HUGETLBFS_SHMEM;
> +	if (ioctl(uffd, UFFDIO_API, &uffdio_api))
> +		ksft_exit_fail_msg("UFFDIO_API\n");
> +
> +	if (!(uffdio_api.api & UFFDIO_REGISTER_MODE_WP) ||
> +	    !(uffdio_api.features & UFFD_FEATURE_WP_UNPOPULATED) ||
> +	    !(uffdio_api.features & UFFD_FEATURE_WP_ASYNC) ||
> +	    !(uffdio_api.features & UFFD_FEATURE_WP_HUGETLBFS_SHMEM))
> +		ksft_exit_fail_msg("UFFDIO_API error %llu\n", uffdio_api.api);

Hi,

I've just noticed that this fails on arm64 because the required features are not
available. It's common practice to skip instead of fail for this sort of
condition (and that's how all the other uffd tests work). The current fail
approach creates noise in our CI.

I see this is already in mm-stable so perhaps we can add a patch to fix on top?

Thanks,
Ryan