From: David Hildenbrand <david@redhat.com>
To: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Shuah Khan" <shuah@kernel.org>, "Dev Jain" <dev.jain@arm.com>,
"Thomas Gleixner" <tglx@linutronix.de>
Cc: linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/3] selftests/mm: virtual_address_range: mmap() without PROT_WRITE
Date: Fri, 10 Jan 2025 16:28:55 +0100 [thread overview]
Message-ID: <1ac669c9-331b-493c-a241-8a7a07716eed@redhat.com> (raw)
In-Reply-To: <20250110-virtual_address_range-tests-v2-1-262a2bf3c3d0@linutronix.de>
On 10.01.25 14:05, Thomas Weißschuh wrote:
> When mapping a larger chunk than physical memory is available with
> PROT_WRITE and overcommit is disabled, the mapping will fail.
> This will prevent the test from running on systems with less then ~1GiB
> of memory and triggering an inscrutinable test failure.
> As the mappings are never written to anyways, the flag can be removed.
>
> Fixes: 010409649885 ("selftests/mm: confirm VA exhaustion without reliance on correctness of mmap()")
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>
> ---
> I went with dropping PROT_WRITE instead of adding MAP_NORESERVE as this
> works even in the face of OVERCOMMIT_NEVER.
Yes, makes sense, it's certainly simpler this way.
Acked-by: David Hildenbrand <david@redhat.com>
--
Cheers,
David / dhildenb
next prev parent reply other threads:[~2025-01-10 15:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-10 13:05 [PATCH v2 0/3] selftests/mm: virtual_address_range: Reduce memory usage and avoid VVAR access Thomas Weißschuh
2025-01-10 13:05 ` [PATCH v2 1/3] selftests/mm: virtual_address_range: mmap() without PROT_WRITE Thomas Weißschuh
2025-01-10 15:28 ` David Hildenbrand [this message]
2025-01-10 15:47 ` Dev Jain
2025-01-10 13:05 ` [PATCH v2 2/3] selftests/mm: virtual_address_range: Unmap chunks after validation Thomas Weißschuh
2025-01-10 15:37 ` David Hildenbrand
2025-01-10 13:05 ` [PATCH v2 3/3] selftests/mm: virtual_address_range: Avoid reading VVAR mappings Thomas Weißschuh
2025-01-10 15:41 ` David Hildenbrand
2025-01-13 9:09 ` Thomas Weißschuh
2025-01-13 9:30 ` David Hildenbrand
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