From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 923E414F6C; Wed, 17 Jul 2024 12:25:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721219107; cv=none; b=oE3xhwiYrYj6iwkflCuP483uzD/pFst+pCJw68YaBARltbv0ZRsRe1hnckvTR93kv19z/wEQkhT5VDnBsvd/Met/CQAlXmE2PZxEIhNWzkU7U4YwrcvoewPWnzS0VHM70mMvplYJIY9Kz5D0SLmDn4eLzW2VamUp7jVqwVOBrho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721219107; c=relaxed/simple; bh=Udj7XoucWRUUlC3jekp3BUuf6p+q68ddaW4kS10dPxc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=im/AuK3xgB8uUV/MnXRwJjSXNeHWf9SGkBF9iXy+U2NoB0uhJuvhd2jGUMD9ltu1JnUqrG/DzhpvHIbfa5W3EON0oRpZ0gJTp5bJPjftsmKC/wr0MrzXrR+pnBRsO8pAbBPZhOR+g1zbbstj72C8nF0lU9NrC0XVOPjvvYwSrW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 21AE11063; Wed, 17 Jul 2024 05:25:30 -0700 (PDT) Received: from [10.57.77.222] (unknown [10.57.77.222]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6A3263F766; Wed, 17 Jul 2024 05:25:03 -0700 (PDT) Message-ID: <423341da-57ae-4e44-a7f6-74f8ebfd3962@arm.com> Date: Wed, 17 Jul 2024 13:25:01 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] selftests/mm: Skip test for non-LPA2 and non-LVA systems Content-Language: en-GB To: Dev Jain , akpm@linux-foundation.org, shuah@kernel.org Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, Anshuman.Khandual@arm.com, broonie@kernel.org References: <20240717111011.316037-1-dev.jain@arm.com> <3782befb-c317-4bb0-a279-c90adb2ec47b@arm.com> From: Ryan Roberts In-Reply-To: <3782befb-c317-4bb0-a279-c90adb2ec47b@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 17/07/2024 13:11, Dev Jain wrote: > > On 7/17/24 17:27, Ryan Roberts wrote: >> On 17/07/2024 12:10, Dev Jain wrote: >>> Post my improvement of the test: >>> https://lore.kernel.org/all/20240522070435.773918-3-dev.jain@arm.com/ >>> The test begins to fail on 4k and 16k pages, on non-LPA2 systems. To >>> reduce noise in the CI systems, let us skip the test when higher address >>> space is not implemented. >>> >>> Signed-off-by: Dev Jain >>> --- >>> The patch applies on linux-next. >>> >>>   tools/testing/selftests/mm/va_high_addr_switch.c | 14 +++++++++++++- >>>   1 file changed, 13 insertions(+), 1 deletion(-) >>> >>> diff --git a/tools/testing/selftests/mm/va_high_addr_switch.c >>> b/tools/testing/selftests/mm/va_high_addr_switch.c >>> index fa7eabfaf841..c6040e1d6e53 100644 >>> --- a/tools/testing/selftests/mm/va_high_addr_switch.c >>> +++ b/tools/testing/selftests/mm/va_high_addr_switch.c >>> @@ -293,6 +293,18 @@ static int run_test(struct testcase *test, int count) >>>       return ret; >>>   } >>>   +/* Check if userspace VA > 48 bits */ >>> +static int high_address_present(void) >>> +{ >>> +    void *ptr = mmap((void *)(1UL << 50), 1, PROT_READ | PROT_WRITE, >>> +             MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); >> I think there is (very unlikely) possibility that something is already mapped at >> this address so it will be replaced due to MAP_FIXED. That could break the test. >> But the only way something could be already mapped is if ARM64_FORCE_52BIT is >> set and in that case, the test will fail anyway, right? So I think this is fine. > > The testcases already assume that high addresses must be empty. Yes, FORCE_52BIT > is the only way something could already be mapped at high addresses, but in that > case the test fails trivially. agreed. > >> >>> +    if (ptr == MAP_FAILED) >>> +        return 0; >>> + >>> +    munmap(ptr, 1); >>> +    return 1; >>> +} >> I'm guessing this will cause a function-not-used warning on arches other than >> arm64? Perhaps wrap it in `#ifdef __aarch64__`? > > Ah yes, I just checked and that is true. I shall post v2 in some time, shall > wait if any more comments are there. With this fixup: Reviewed-by: Ryan Roberts > >> >> Thanks, >> Ryan >> >>> + >>>   static int supported_arch(void) >>>   { >>>   #if defined(__powerpc64__) >>> @@ -300,7 +312,7 @@ static int supported_arch(void) >>>   #elif defined(__x86_64__) >>>       return 1; >>>   #elif defined(__aarch64__) >>> -    return 1; >>> +    return high_address_present(); >>>   #else >>>       return 0; >>>   #endif