From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5DD6C210E4 for ; Wed, 17 Jul 2024 07:13:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721200394; cv=none; b=WUwoDm64fgFcbGwoIvOEAvXNV5+IXZ49J0AaXVEesPHwGzqtkrgCHSuv0ZKgl8rnJBma2pcWsuZnTHdrPdLPBzw5tOoO7hmx9pztz0O8lfT8x5X9awyC5BfnhZqayVFR3hWtFkXMz7dwr6E9qKaRdttfaVNUqkceW0WOBJM+7fc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721200394; c=relaxed/simple; bh=UR8xP6eJEfkiVPFIaOHP4a7M2srFuVsTdl6wNRNUQis=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NvIRimyNRYeVosk84cyVTQpGhzJRgX0T1ouTcrmFZbT2/nGO/9eNx82OmpU1SenR2q7rNFvEs3pb5cyIZyHEDruHTqvOEbPl2tTsvbJqX3fnIO6MreQUD6Rf25PGkTjELYl4OV0I1exw0wlBNwvGnhPDVtEpvJdfqhC+tQUFbG8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 237961480; Wed, 17 Jul 2024 00:13:38 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 228DD3F762; Wed, 17 Jul 2024 00:13:11 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , Hugh Dickins , Jonathan Corbet , "Matthew Wilcox (Oracle)" , David Hildenbrand , Barry Song , Lance Yang , Baolin Wang , Gavin Shan , Pankaj Raghav , Daniel Gomez Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1 3/4] mm: Override mTHP "enabled" defaults at kernel cmdline Date: Wed, 17 Jul 2024 08:12:55 +0100 Message-ID: <20240717071257.4141363-4-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240717071257.4141363-1-ryan.roberts@arm.com> References: <20240717071257.4141363-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add thp_anon= cmdline parameter to allow specifying the default enablement of each supported anon THP size. The parameter accepts the following format and can be provided multiple times to configure each size: thp_anon=[KMG]: See Documentation/admin-guide/mm/transhuge.rst for more details. Configuring the defaults at boot time is useful to allow early user space to take advantage of mTHP before its been configured through sysfs. Signed-off-by: Ryan Roberts --- .../admin-guide/kernel-parameters.txt | 8 +++ Documentation/admin-guide/mm/transhuge.rst | 26 +++++++-- mm/huge_memory.c | 55 ++++++++++++++++++- 3 files changed, 82 insertions(+), 7 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bc55fb55cd26..48443ad12e3f 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6592,6 +6592,14 @@ : poll all this frequency 0: no polling (default) + thp_anon= [KNL] + Format: [KMG]:always|madvise|never|inherit + Can be used to control the default behavior of the + system with respect to anonymous transparent hugepages. + Can be used multiple times for multiple anon THP sizes. + See Documentation/admin-guide/mm/transhuge.rst for more + details. + threadirqs [KNL,EARLY] Force threading of all interrupt handlers except those marked explicitly IRQF_NO_THREAD. diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 1aaf8e3a0b5a..f53d43d986e2 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -311,13 +311,27 @@ performance. Note that any changes to the allowed set of sizes only applies to future file-backed THP allocations. -Boot parameter -============== +Boot parameters +=============== -You can change the sysfs boot time defaults of Transparent Hugepage -Support by passing the parameter ``transparent_hugepage=always`` or -``transparent_hugepage=madvise`` or ``transparent_hugepage=never`` -to the kernel command line. +You can change the sysfs boot time default for the top-level "enabled" +control by passing the parameter ``transparent_hugepage=always`` or +``transparent_hugepage=madvise`` or ``transparent_hugepage=never`` to the +kernel command line. + +Alternatively, each supported anonymous THP size can be controlled by +passing ``thp_anon=[KMG]:``, where ```` is the THP size +and ```` is one of ``always``, ``madvise``, ``never`` or +``inherit``. + +For example, the following will set 64K THP to ``always``:: + + thp_anon=64K:always + +``thp_anon=`` may be specified multiple times to configure all THP sizes as +required. If ``thp_anon=`` is specified at least once, any anon THP sizes +not explicitly configured on the command line are implicitly set to +``never``. Hugepages in tmpfs/shmem ======================== diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 4249c0bc9388..794d2790d90d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -82,6 +82,7 @@ unsigned long huge_anon_orders_madvise __read_mostly; unsigned long huge_anon_orders_inherit __read_mostly; unsigned long huge_file_orders_always __read_mostly; int huge_file_exec_order __read_mostly = -1; +static bool anon_orders_configured; unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma, unsigned long vm_flags, @@ -763,7 +764,10 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) * disable all other sizes. powerpc's PMD_ORDER isn't a compile-time * constant so we have to do this here. */ - huge_anon_orders_inherit = BIT(PMD_ORDER); + if (!anon_orders_configured) { + huge_anon_orders_inherit = BIT(PMD_ORDER); + anon_orders_configured = true; + } /* * For pagecache, default to enabling all orders. powerpc's PMD_ORDER @@ -955,6 +959,55 @@ static int __init setup_transparent_hugepage(char *str) } __setup("transparent_hugepage=", setup_transparent_hugepage); +static int __init setup_thp_anon(char *str) +{ + unsigned long size; + char *state; + int order; + int ret = 0; + + if (!str) + goto out; + + size = (unsigned long)memparse(str, &state); + order = ilog2(size >> PAGE_SHIFT); + if (*state != ':' || !is_power_of_2(size) || size <= PAGE_SIZE || + !(BIT(order) & THP_ORDERS_ALL_ANON)) + goto out; + + state++; + + if (!strcmp(state, "always")) { + clear_bit(order, &huge_anon_orders_inherit); + clear_bit(order, &huge_anon_orders_madvise); + set_bit(order, &huge_anon_orders_always); + ret = 1; + } else if (!strcmp(state, "inherit")) { + clear_bit(order, &huge_anon_orders_always); + clear_bit(order, &huge_anon_orders_madvise); + set_bit(order, &huge_anon_orders_inherit); + ret = 1; + } else if (!strcmp(state, "madvise")) { + clear_bit(order, &huge_anon_orders_always); + clear_bit(order, &huge_anon_orders_inherit); + set_bit(order, &huge_anon_orders_madvise); + ret = 1; + } else if (!strcmp(state, "never")) { + clear_bit(order, &huge_anon_orders_always); + clear_bit(order, &huge_anon_orders_inherit); + clear_bit(order, &huge_anon_orders_madvise); + ret = 1; + } + + if (ret) + anon_orders_configured = true; +out: + if (!ret) + pr_warn("thp_anon=%s: cannot parse, ignored\n", str); + return ret; +} +__setup("thp_anon=", setup_thp_anon); + pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { if (likely(vma->vm_flags & VM_WRITE)) -- 2.43.0