From nobody Mon Nov 25 09:32:18 2024 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (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 E56C917BD6; Tue, 29 Oct 2024 00:24:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730161459; cv=none; b=MSVbkE5LlljWEpwhcK/4gnFjP8328ODdxf5gAAjZEyUD2N2pFtuG0lNKWjg0ZfUkX/vWXK4irBcaTjlxI2Er6nV+9kNSlviiK77vUB8QDtkhPboemK3jMmCnpCkIYmccy8yEU6YKCxyDtVFXXT+I1br81qLaekwmt5vhTOWgwbA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730161459; c=relaxed/simple; bh=DDEEbY5NKTODUyQzjfOpOKJVymT68lWkQwWLp7Dd1PI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=fpTM6Aaz3ez8z6UKeeTUTsj1mwyEQGEsWCSypvNJnteMoyKAM83ISgUqNqW25XmRRx9ZYWBQY8miY/9PJaL2MXRwa6gg3yYS9ZfKOTLgcQ0mPW+bJT/jPJY01OUMYs80abqDI2mU9GFw3DC0By0dUXfzz9Zr925Pd6RvdI1VqJc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=icCQQT2l; arc=none smtp.client-ip=178.60.130.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="icCQQT2l" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=BwshJwo48RIhJnqvpdLmCKcZc0vOflKYESOeF9s3h5g=; b=icCQQT2lxYD/Bkswn+kH5dOcQl 4OyL053b9xdV1IU4hvc3z6E6kEqCdEQKIEOC3InqAVEdZmg0nkJYzr+9gIoHMpwBzRVEPPwROwdcz 1raCGT8RCC7Uh3t7hjq/6slsuJgezXZxSUq/LCx//sXBjGDMmcZ7r1nBGM9G1BoVBC2Hq6ZqUHRYk 31RYRo3CfcM+ElquSuLvP2lxg7i46wfBU+3vacpv/2Rd5XwuCzqZksb1AGiXJZJe93JRyWhLd5r1U /P0X6aHHZdihEbdOoe/XLiNuG6lQRhNlmCNnt3Pwcpm5Max35hEfROmuCh3Doo7ExtT6383OxEDOZ /B+mHGrg==; Received: from [187.36.213.55] (helo=morissey..) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1t5a1k-00GIrd-8p; Tue, 29 Oct 2024 01:24:04 +0100 From: =?UTF-8?q?Ma=C3=ADra=20Canal?= To: Jonathan Corbet , Andrew Morton , Hugh Dickins , Barry Song , David Hildenbrand , Ryan Roberts , Baolin Wang , Lance Yang Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-dev@igalia.com, =?UTF-8?q?Ma=C3=ADra=20Canal?= Subject: [PATCH v2 4/4] mm: shmem: override mTHP shmem default with a kernel parameter Date: Mon, 28 Oct 2024 21:13:08 -0300 Message-ID: <20241029002324.1062723-5-mcanal@igalia.com> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241029002324.1062723-1-mcanal@igalia.com> References: <20241029002324.1062723-1-mcanal@igalia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Add the ``thp_shmem=3D`` kernel command line to allow specifying the default policy of each supported shmem hugepage size. The kernel parameter accepts the following format: thp_shmem=3D[KMG],[KMG]:;[KMG]-[KMG]: For example, thp_shmem=3D16K-64K:always;128K,512K:inherit;256K:advise;1M-2M:never;4M-8= M:within_size By configuring the default policy of several shmem hugepages, the user can take advantage of mTHP before it's been configured through sysfs. Signed-off-by: Ma=C3=ADra Canal --- .../admin-guide/kernel-parameters.txt | 10 +++++ Documentation/admin-guide/mm/transhuge.rst | 17 +++++++++ mm/shmem.c | 38 ++++++++++++++++++- 3 files changed, 64 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index acabb04d0dd4..b48d744d99b0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6700,6 +6700,16 @@ Force threading of all interrupt handlers except those marked explicitly IRQF_NO_THREAD. =20 + thp_shmem=3D [KNL] + Format: [KMG],[KMG]:;[KMG]-[KMG]: + Control the default policy of each hugepage size for the + internal shmem mount. is one of policies available + for the shmem mount ("always", "inherit", "never", "within_size", + and "advise"). + It can be used multiple times for multiple shmem THP sizes. + See Documentation/admin-guide/mm/transhuge.rst for more + details. + topology=3D [S390,EARLY] Format: {off | on} Specify if the kernel should make use of the cpu diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/adm= in-guide/mm/transhuge.rst index 9b5b02c4d1ab..47e7fc30e22d 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -332,6 +332,23 @@ allocation policy for the internal shmem mount by usin= g the kernel parameter seven valid policies for shmem (``always``, ``within_size``, ``advise``, ``never``, ``deny``, and ``force``). =20 +In the same manner as ``thp_anon`` controls each supported anonymous THP +size, ``thp_shmem`` controls each supported shmem THP size. ``thp_shmem`` +has the same format as ``thp_anon``, but also supports the policy +``within_size``. + +``thp_shmem=3D`` may be specified multiple times to configure all THP sizes +as required. If ``thp_shmem=3D`` is specified at least once, any shmem THP +sizes not explicitly configured on the command line are implicitly set to +``never``. + +``transparent_hugepage_shmem`` setting only affects the global toggle. If +``thp_shmem`` is not specified, PMD_ORDER hugepage will default to +``inherit``. However, if a valid ``thp_shmem`` setting is provided by the +user, the PMD_ORDER hugepage policy will be overridden. If the policy for +PMD_ORDER is not defined within a valid ``thp_shmem``, its policy will +default to ``never``. + Hugepages in tmpfs/shmem =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 diff --git a/mm/shmem.c b/mm/shmem.c index 26c1eb1b4b1d..37951bb863dd 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -136,6 +136,7 @@ static unsigned long huge_shmem_orders_always __read_mo= stly; static unsigned long huge_shmem_orders_madvise __read_mostly; static unsigned long huge_shmem_orders_inherit __read_mostly; static unsigned long huge_shmem_orders_within_size __read_mostly; +static bool shmem_orders_configured __initdata; #endif =20 #ifdef CONFIG_TMPFS @@ -5027,7 +5028,8 @@ void __init shmem_init(void) * Default to setting PMD-sized THP to inherit the global setting and * disable all other multi-size THPs. */ - huge_shmem_orders_inherit =3D BIT(HPAGE_PMD_ORDER); + if (!shmem_orders_configured) + huge_shmem_orders_inherit =3D BIT(HPAGE_PMD_ORDER); #endif return; =20 @@ -5184,6 +5186,7 @@ struct kobj_attribute thpsize_shmem_enabled_attr =3D =20 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) =20 + static int __init setup_transparent_hugepage_shmem(char *str) { int huge, ret =3D 0; @@ -5207,6 +5210,39 @@ static int __init setup_transparent_hugepage_shmem(c= har *str) } __setup("transparent_hugepage_shmem=3D", setup_transparent_hugepage_shmem); =20 +static char str_dup[PAGE_SIZE] __initdata; +static int __init setup_thp_shmem(char *str) +{ + struct thp_policy_bitmap policies[] =3D { + { "always", huge_shmem_orders_always }, + { "inherit", huge_shmem_orders_inherit }, + { "advise", huge_shmem_orders_madvise }, + { "within_size", huge_shmem_orders_within_size } + }; + char *p; + + if (!str || strlen(str) + 1 > PAGE_SIZE) + goto err; + + strscpy(str_dup, str); + p =3D str_dup; + + if (!parse_huge_orders(p, policies, ARRAY_SIZE(policies), + THP_ORDERS_ALL_FILE_DEFAULT)) + goto err; + + huge_shmem_orders_always =3D policies[0].bitmap; + huge_shmem_orders_inherit =3D policies[1].bitmap; + huge_shmem_orders_madvise =3D policies[2].bitmap; + huge_shmem_orders_within_size =3D policies[3].bitmap; + shmem_orders_configured =3D true; + return 1; +err: + pr_warn("thp_shmem=3D%s: error parsing string, ignoring setting\n", str); + return 0; +} +__setup("thp_shmem=3D", setup_thp_shmem); + #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ =20 #else /* !CONFIG_SHMEM */ --=20 2.46.2