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 9F17A43DA3F; Mon, 11 May 2026 16:32:06 +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=1778517126; cv=none; b=Lzl2yg0jnMYkJ9vKb/BI/Xrm+fLsdWQpSQWgkpiBjRASqWsApaumiiVhplzm91TV6kp6H4NLvj6jL4oBYbnXcyeSpBQzMRBEbOBW76Cr9Rwt31ko2iAve4TIyOsdctEDBe+Qoxth48RXo2LwXuw04/DsRnNifL2CH+rU9U3dt/k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778517126; c=relaxed/simple; bh=z0JhOy+pHH/aI/Vimu7SOjVZzwdCPvl2MrL9FynQd78=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MMsR6A0KxQikkn3ZsSlosmnlMfmCbCyBtzcx3C0tbG7U8+HTDj1n1bBGsyuwsAOdCneFT2PtoCnwKqqW2xdTOZkqdqSher2fkkTNC8JRxVLVXJQ1sn3K+p3LWKiL3VxS1dxD4MrUlxnU7Xt6oSd+P8LfIMmfBZItYMMz8/Uui+8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pa7utrSP; 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="pa7utrSP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18D5DC2BCB0; Mon, 11 May 2026 16:31:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778517126; bh=z0JhOy+pHH/aI/Vimu7SOjVZzwdCPvl2MrL9FynQd78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pa7utrSPXMPGNdz7bT41cMR+W0vj3TNLW7cbRM4lEY6I+HX4WtA6+BPt4o18iOvw7 AlIyzj4lOIQVm1ifNXdnYVZsryhRNNIPW0LaoFn7R15NwAtKm0B+k3GZ3cdDctIfSg ADfOS3lRarImeNqPRshM7+B/J3lZ/cXhSX3axHtqk8R6Z0jmm6+flF1yU0+RP2Vu7F Cd3SPW4aI9ZJOJxHQcuPrAsxrcOmtrMQUjmPsFXbR34uGBRrbBKSiwRTGinrRVsQ1W yj4rp+jDJFWD6LdwoJEw/9lnMQlz0BvYcLeoAi+t7I1XULXNFQDFEY/oFrJoVscAhV 7nXoG4EEJxruA== From: Mike Rapoport To: Andrew Morton , David Hildenbrand Cc: Baolin Wang , Barry Song , Dev Jain , Donet Tom , Jason Gunthorpe , John Hubbard , "Liam R. Howlett" , Lance Yang , Li Wang , Leon Romanovsky , Lorenzo Stoakes , Luiz Capitulino , Mark Brown , Michal Hocko , Mike Rapoport , Nico Pache , Peter Xu , Ryan Roberts , Sarthak Sharma , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , Zi Yan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v4 30/55] selftests/mm: vm_util: add helpers to set and restore shm limits Date: Mon, 11 May 2026 19:28:14 +0300 Message-ID: <20260511162840.375890-31-rppt@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260511162840.375890-1-rppt@kernel.org> References: <20260511162840.375890-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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. Tested-by: Luiz Capitulino Tested-by: Sarthak Sharma 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 9256bbbe38ea..336a26751d3f 100644 --- a/tools/testing/selftests/mm/vm_util.c +++ b/tools/testing/selftests/mm/vm_util.c @@ -760,3 +760,31 @@ 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