From nobody Sun Nov 24 22:56:53 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 DCC661B4F2D; Fri, 1 Nov 2024 16:58:23 +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=1730480306; cv=none; b=PNfwORbMjKjRbk1pt97EiqbmA/ye8hSEWmjgoNN93Zzs2+/DlQpi52cUo2alCytJoK4cjHvrn6RCPEfJaL0AC9gtQjGkORnxA9Bhi4REuvjMTLQ2pIhzktCiRFfYjgcjcgghgtZXCiEtiiUAnRPzHzuCxKHrpixz5xqXQulsekI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730480306; c=relaxed/simple; bh=pZTHNwdxs87D8Qujr7aGSzyq2v1Xo87Y5XjXiysdO3Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gTeoXrdHXKi90Rg45BD9eW5G2tyVK3cS2TJYjqAoiH6nD2PvizHy6CKaeWeElM/TrjhIg0vxnCzi29PFC037hC7z0fgEI25Daa3lEfFY0kqo0cpmgormcggjPljHfcqc7sYuh1iC2Da9rtmCwgnIVkVkNY7s3MTqF5ic3AdE818= 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=L0ixQzk5; 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="L0ixQzk5" 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=Ys/vY/e+8yfzEKIu4LKRRFsTDzyvnthR/qzPM3DoISA=; b=L0ixQzk5rq1dwuZsLc85aKbjG6 DAAXXvrSlteNqKUke8PbLf3vBNPrMAOM34JG4VCZVKC6ajdzj5OU2oaaC77BC7JfRpwKnDRcvVwSc +3QYDyAqKYcIm0G/DOXybSkBhzfv/I2klwXRJgts6ftfa9RTM64lgA3BcXW3+anSPMCXZ8IJ7Aass F0+84tV+OUgvxfFcfDK6gUVp2eiyZ+JCYbxOv2uz56Mx5EFbP1ZlKLyiEzNsomfZmc3wqKAnxh2Yg ZdrTRfXJtpPkmDFYe5Rdq2BH/ia1U+T0KujDqpsCN+BrU1aSrtkEW6fsiHvJbY7Ng+jSShxl52vNe 6yR4etKg==; 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 1t6uyR-000VPu-59; Fri, 01 Nov 2024 17:58:11 +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, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-dev@igalia.com, =?UTF-8?q?Ma=C3=ADra=20Canal?= Subject: [PATCH v5 4/5] mm: shmem: override mTHP shmem default with a kernel parameter Date: Fri, 1 Nov 2024 13:54:08 -0300 Message-ID: <20241101165719.1074234-6-mcanal@igalia.com> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241101165719.1074234-2-mcanal@igalia.com> References: <20241101165719.1074234-2-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-8M:= within_size Some GPUs may benefit from using huge pages. Since DRM GEM uses shmem to allocate anonymous pageable memory, it=E2=80=99s essential to control th= e huge page allocation policy for the internal shmem mount. This control can be achieved through the ``transparent_hugepage_shmem=3D`` parameter. Beyond just setting the allocation policy, it=E2=80=99s crucial to have gra= nular control over the size of huge pages that can be allocated. The GPU may support only specific huge page sizes, and allocating pages larger/smaller than those sizes would be ineffective. Signed-off-by: Ma=C3=ADra Canal Reviewed-by: Baolin Wang --- .../admin-guide/kernel-parameters.txt | 10 ++ Documentation/admin-guide/mm/transhuge.rst | 17 +++ mm/shmem.c | 105 +++++++++++++++++- 3 files changed, 131 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 9c6f6da612c4..5034915f4e8e 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 dfcc88ec6e34..d2bf98aece40 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 @@ -5195,6 +5197,107 @@ static int __init setup_transparent_hugepage_shmem(= char *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) +{ + char *token, *range, *policy, *subtoken; + unsigned long always, inherit, madvise, within_size; + char *start_size, *end_size; + int start, end, nr; + char *p; + + if (!str || strlen(str) + 1 > PAGE_SIZE) + goto err; + strscpy(str_dup, str); + + always =3D huge_shmem_orders_always; + inherit =3D huge_shmem_orders_inherit; + madvise =3D huge_shmem_orders_madvise; + within_size =3D huge_shmem_orders_within_size; + p =3D str_dup; + while ((token =3D strsep(&p, ";")) !=3D NULL) { + range =3D strsep(&token, ":"); + policy =3D token; + + if (!policy) + goto err; + + while ((subtoken =3D strsep(&range, ",")) !=3D NULL) { + if (strchr(subtoken, '-')) { + start_size =3D strsep(&subtoken, "-"); + end_size =3D subtoken; + + start =3D get_order_from_str(start_size, + THP_ORDERS_ALL_FILE_DEFAULT); + end =3D get_order_from_str(end_size, + THP_ORDERS_ALL_FILE_DEFAULT); + } else { + start_size =3D end_size =3D subtoken; + start =3D end =3D get_order_from_str(subtoken, + THP_ORDERS_ALL_FILE_DEFAULT); + } + + if (start =3D=3D -EINVAL) { + pr_err("invalid size %s in thp_shmem boot parameter\n", + start_size); + goto err; + } + + if (end =3D=3D -EINVAL) { + pr_err("invalid size %s in thp_shmem boot parameter\n", + end_size); + goto err; + } + + if (start < 0 || end < 0 || start > end) + goto err; + + nr =3D end - start + 1; + if (!strcmp(policy, "always")) { + bitmap_set(&always, start, nr); + bitmap_clear(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&within_size, start, nr); + } else if (!strcmp(policy, "advise")) { + bitmap_set(&madvise, start, nr); + bitmap_clear(&inherit, start, nr); + bitmap_clear(&always, start, nr); + bitmap_clear(&within_size, start, nr); + } else if (!strcmp(policy, "inherit")) { + bitmap_set(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&always, start, nr); + bitmap_clear(&within_size, start, nr); + } else if (!strcmp(policy, "within_size")) { + bitmap_set(&within_size, start, nr); + bitmap_clear(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&always, start, nr); + } else if (!strcmp(policy, "never")) { + bitmap_clear(&inherit, start, nr); + bitmap_clear(&madvise, start, nr); + bitmap_clear(&always, start, nr); + bitmap_clear(&within_size, start, nr); + } else { + pr_err("invalid policy %s in thp_shmem boot parameter\n", policy); + goto err; + } + } + } + + huge_shmem_orders_always =3D always; + huge_shmem_orders_madvise =3D madvise; + huge_shmem_orders_inherit =3D inherit; + huge_shmem_orders_within_size =3D within_size; + 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