From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E01BA3803EB; Mon, 6 Apr 2026 14:20:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775485228; cv=none; b=ZiiXIm5fWR0A8AhOqaYlvdcsqxoRpZiq837YVmjKBbH8msBoWJ84kO2ZtiC4mKOq69L5/YCHm7Ssp6JLVNg5u5+mTpIlibmSUCYznb3EA3U/6wJmKh9YxQX3z4vqcrEFZ1SLNpD4pttSR6w2XKdHLoHWCJCUlpFYjYmvU4HEVDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775485228; c=relaxed/simple; bh=tO4w/saWs4TngI1dGJjVb/BDaQv7f0xtr7dZaOtNvYY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B11arhg1RjuDyHlMhNMxhkUuq7mWHvV5g063Thv650u/EJWZvtvaiVQcSPTaaiiyqKBVv+Vg5C8SIeTy6+Li64SMco1LQsx4XX/S96WchMbPXNWhE5Su7hhgSS2hjf9lPxZoO0ZJk/c3benBqMT3BOkYyLn5wM8beM2y5gnTx5A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qPJrWVSY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qPJrWVSY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A920C4CEF7; Mon, 6 Apr 2026 14:20:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775485228; bh=tO4w/saWs4TngI1dGJjVb/BDaQv7f0xtr7dZaOtNvYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qPJrWVSYPEcYgqWceoyxpdlNMa2cxJaWbuvyhl+Wf32f9z5uavVsPdQxgPzIrwgHQ N8JmXTzhzNKBsrEB70pVaZMU8CYlUI7oDNSG73oQXwTHZBInQf8/zwChhEaIZnzdVS Xwe6wmCtsUfN0mgHw1NR/CtQoMf0Q4dXbCl9SlPDX/LA8UuFZUz6m7xmu323Ikl8dr 0aNx9EcqzS47/Mpmpv03X7uHOccrv9ixIK7P8i2zRLkle+wyHtivXl0jNdkFuGxiEj 423+e1VWKXe/FPU3eIjleclk73L9pctdblACnQynTaVw1SujZj6LkUGuoIJX/kFibi aZ2lyEbPLiRrw== From: Mike Rapoport To: Andrew Morton , David Hildenbrand Cc: Baolin Wang , Barry Song , Dev Jain , Jason Gunthorpe , John Hubbard , "Liam R. Howlett" , Lance Yang , Leon Romanovsky , Lorenzo Stoakes , Mark Brown , Michal Hocko , Mike Rapoport , Nico Pache , Peter Xu , Ryan Roberts , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , Zi Yan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 28/53] selftests/mm: vm_util: add helpers to set and restore shm limits Date: Mon, 6 Apr 2026 17:17:10 +0300 Message-ID: <20260406141735.2179309-29-rppt@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260406141735.2179309-1-rppt@kernel.org> References: <20260406141735.2179309-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Mike Rapoport (Microsoft)" hugetlb-shm and thuge-gen tests require that limits defined by /proc/sys/kernel/{shmmax,shmall} should be higher than certain values. Add helpers that allow setting these limits and restoring their settings on a test exit. They will be used later in hugetlb-shm and thuge-gen. Signed-off-by: Mike Rapoport (Microsoft) --- tools/testing/selftests/mm/vm_util.c | 28 ++++++++++++++++++++++++++++ tools/testing/selftests/mm/vm_util.h | 9 +++++++++ 2 files changed, 37 insertions(+) diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c index 752566f75c0b..5a89c2d903be 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -761,3 +761,31 @@ void write_num(const char *path, unsigned long num) sprintf(buf, "%lu", num); write_file(path, buf, strlen(buf) + 1); } + +static unsigned long shmall, shmmax; + +void __shm_limits_restore(void) +{ + if (shmmax) + write_num("/proc/sys/kernel/shmmax", shmmax); + if (shmall) + write_num("/proc/sys/kernel/shmall", shmall); +} + +void shm_limits_prepare(unsigned long length) +{ + unsigned long nr = length / psize(); + unsigned long val; + + val = read_num("/proc/sys/kernel/shmmax"); + if (val < length) { + write_num("/proc/sys/kernel/shmmax", length); + shmmax = val; + } + + val = read_num("/proc/sys/kernel/shmall"); + if (val < nr) { + write_num("/proc/sys/kernel/shmall", nr); + shmall = val; + } +} diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h index 5fc9707f6b9a..ea8fc8fdf0eb 100644 --- a/tools/testing/selftests/mm/vm_util.h +++ b/tools/testing/selftests/mm/vm_util.h @@ -168,3 +168,12 @@ void write_file(const char *path, const char *buf, size_t buflen); int read_file(const char *path, char *buf, size_t buflen); unsigned long read_num(const char *path); void write_num(const char *path, unsigned long num); + +void shm_limits_prepare(unsigned long length); +void __shm_limits_restore(void); + +#define SHM_LIMITS_RESTORE() \ +static void __attribute__((destructor)) shm_limits_restore(void) \ +{ \ + __shm_limits_restore(); \ +} -- 2.53.0