From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 926AB366049 for ; Tue, 25 Aug 2026 01:54:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787622880; cv=none; b=CtYzQFDymABsdl3hmuVQ9NNWgcPBRONtO3LirWLO+t21FusSuKy/nYBJ4ERaIo0/bhzhNPjN6wA8g1izyeDOmkuRt9kZL5DzvjPlzCimyD7UtKL9hh1aAT0PKZL+5sJYEH2PyQQ7Tzv1HBNTj3uptKr/ETuB5hvdtj+vzAaKv7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787622880; c=relaxed/simple; bh=Mc/Q3zgdnII1wCQ/BUFXH8nN4bWSUVfP8igmUJIn3qU=; h=Date:To:From:Subject:Message-Id; b=e9YdbY6ba105uqFyRd+U7N3XjGePIcPI/8MU2nEjSlNOaRIoIZYtJuW6OGRJf2npX+RG5qBgpTq/bOspaHdXBg9xjsqaoLbUP/QThVUCxdlz+orj+GzWbmWAnxpCwMbqAiFyvLCIS0xh1jLEmaPOtrVnLlNZfz6ECw5E79SctRw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=rVGR0hO/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="rVGR0hO/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 516B91F000E9; Tue, 25 Aug 2026 01:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787622873; bh=tDS5v87dzyS1YoKhVcHTVrCLQp5WWHQ4yAP05z6esGc=; h=Date:To:From:Subject; b=rVGR0hO/Fe29mKut1I9zMvaxZd+2dGmWfeqwwJRgB5+fqEw6Y4RpzSRclta8yc/dD 3YG8h+r5PRkNx5ZEfKtlHlgu+6JGIFvviFLvXvi0YAoLjmriTjwRpUcSrmEJt3YPbA O3PsBFrWt9//3viTGei+Upg4C4uKxRsdh9xRE2kE= Date: Mon, 24 Aug 2026 18:54:32 -0700 To: mm-commits@vger.kernel.org,usama.arif@linux.dev,surenb@google.com,rientjes@google.com,osalvador@suse.de,muchun.song@linux.dev,gthelen@google.com,fvdl@google.com,david@kernel.org,souravpanda@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-hugetlb_cma-support-percentage-based-hugetlb_cma-reservation.patch removed from -mm tree Message-Id: <20260825015433.516B91F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/hugetlb_cma: support percentage-based hugetlb_cma reservation has been removed from the -mm tree. Its filename was mm-hugetlb_cma-support-percentage-based-hugetlb_cma-reservation.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sourav Panda Subject: mm/hugetlb_cma: support percentage-based hugetlb_cma reservation Date: Fri, 7 Aug 2026 04:00:03 +0000 Currently, hugetlb_cma reservation only supports absolute sizes (e.g., hugetlb_cma=2G or hugetlb_cma=0:1G,1:1G). This can be restrictive in heterogeneous environments or when deploying common kernel command lines across machines with different memory capacities. Add support for percentage-based hugetlb_cma reservation (e.g., hugetlb_cma=20% or hugetlb_cma=0:20%,1:10%). The percentage is calculated against the total memory (for global settings) or against the node-specific memory (for node-specific settings) using memblock APIs during early boot. Link: https://lore.kernel.org/20260807040003.2156630-1-souravpanda@google.com Signed-off-by: Sourav Panda Acked-by: Usama Arif Cc: David Hildenbrand Cc: David Rientjes Cc: Frank van der Linden Cc: Greg Thelen Cc: Muchun Song Cc: Oscar Salvador Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- Documentation/admin-guide/kernel-parameters.txt | 10 mm/hugetlb_cma.c | 142 +++++++++++++- 2 files changed, 142 insertions(+), 10 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt~mm-hugetlb_cma-support-percentage-based-hugetlb_cma-reservation +++ a/Documentation/admin-guide/kernel-parameters.txt @@ -2064,8 +2064,14 @@ Kernel parameters hugetlb_cma= [HW,CMA,EARLY] The size of a CMA area used for allocation of gigantic hugepages. Or using node format, the size of a CMA area per node can be specified. - Format: nn[KMGTPE] or (node format) - :nn[KMGTPE][,:nn[KMGTPE]] + The size can be an absolute value (e.g., 2G) or a + percentage of the total memory or node memory (e.g., 20%). + Percentage-derived sizes are rounded down to a multiple of + the architecture's gigantic hugepage size and may become + zero. + Format: nn[KMGTPE] or nn% or (node format) + :nn[KMGTPE][,:nn[KMGTPE]] or + :nn%[,:nn%] The size must be a multiple of the gigantic page size. When using node format, this applies to each per-node size. --- a/mm/hugetlb_cma.c~mm-hugetlb_cma-support-percentage-based-hugetlb_cma-reservation +++ a/mm/hugetlb_cma.c @@ -9,6 +9,9 @@ #include #include +#include +#include +#include #include "internal.h" #include "hugetlb_cma.h" @@ -18,6 +21,28 @@ static unsigned long hugetlb_cma_size_in static bool hugetlb_cma_only __ro_after_init; static unsigned long hugetlb_cma_size __ro_after_init; +static unsigned int hugetlb_cma_percent __initdata; +static unsigned int hugetlb_cma_percent_in_node[MAX_NUMNODES] __initdata; + +#ifdef CONFIG_NUMA +static phys_addr_t __init memblock_node_memory_size(int nid) +{ + struct memblock_region *reg; + phys_addr_t size = 0; + + for_each_mem_region(reg) { + if (reg->nid == nid) + size += reg->size; + } + return size; +} +#else +static phys_addr_t __init memblock_node_memory_size(int nid) +{ + return memblock_phys_mem_size(); +} +#endif + void hugetlb_cma_free_frozen_folio(struct folio *folio) { WARN_ON_ONCE(!cma_release_frozen(hugetlb_cma[folio_nid(folio)], @@ -90,14 +115,31 @@ static int __init cmdline_parse_hugetlb_ break; if (s[count] == ':') { + char *next; + if (tmp >= MAX_NUMNODES) break; nid = array_index_nospec(tmp, MAX_NUMNODES); + hugetlb_cma_size = 0; + hugetlb_cma_percent = 0; + s += count + 1; - tmp = memparse(s, &s); - hugetlb_cma_size_in_node[nid] = tmp; - hugetlb_cma_size += tmp; + tmp = memparse(s, &next); + if (*next == '%') { + if (tmp > 100) { + pr_warn("hugetlb_cma: invalid percentage %lu for node %d\n", + tmp, nid); + break; + } + hugetlb_cma_percent_in_node[nid] = tmp; + hugetlb_cma_size_in_node[nid] = 0; + s = next + 1; + } else { + hugetlb_cma_size_in_node[nid] = tmp; + hugetlb_cma_percent_in_node[nid] = 0; + s = next; + } /* * Skip the separator if have one, otherwise @@ -108,7 +150,28 @@ static int __init cmdline_parse_hugetlb_ else break; } else { - hugetlb_cma_size = memparse(p, &p); + char *next; + + tmp = memparse(p, &next); + if (*next == '%') { + if (tmp > 100) { + pr_warn("hugetlb_cma: invalid percentage %lu\n", tmp); + } else { + hugetlb_cma_percent = tmp; + hugetlb_cma_size = 0; + for (nid = 0; nid < MAX_NUMNODES; nid++) { + hugetlb_cma_size_in_node[nid] = 0; + hugetlb_cma_percent_in_node[nid] = 0; + } + } + } else { + hugetlb_cma_size = tmp; + hugetlb_cma_percent = 0; + for (nid = 0; nid < MAX_NUMNODES; nid++) { + hugetlb_cma_size_in_node[nid] = 0; + hugetlb_cma_percent_in_node[nid] = 0; + } + } break; } } @@ -134,8 +197,36 @@ void __init hugetlb_cma_reserve(void) { unsigned long size, reserved, per_node, order, gigantic_page_size; bool node_specific_cma_alloc = false; + bool has_node_specific_param = false; int nid; + for (nid = 0; nid < MAX_NUMNODES; nid++) { + if (hugetlb_cma_size_in_node[nid] || hugetlb_cma_percent_in_node[nid]) { + has_node_specific_param = true; + break; + } + } + + if (has_node_specific_param) { + hugetlb_cma_size = 0; + for (nid = 0; nid < MAX_NUMNODES; nid++) { + if (hugetlb_cma_percent_in_node[nid]) { + phys_addr_t node_gfp_mem = memblock_node_memory_size(nid); + u64 s; + + s = mul_u64_u32_div((u64)node_gfp_mem, + hugetlb_cma_percent_in_node[nid], + 100); + + hugetlb_cma_size_in_node[nid] = s; + } + hugetlb_cma_size += hugetlb_cma_size_in_node[nid]; + } + } else if (hugetlb_cma_percent) { + hugetlb_cma_size = mul_u64_u32_div((u64)memblock_phys_mem_size(), + hugetlb_cma_percent, 100); + } + if (!hugetlb_cma_size) return; @@ -154,6 +245,32 @@ void __init hugetlb_cma_reserve(void) VM_WARN_ON(order <= MAX_PAGE_ORDER); gigantic_page_size = PAGE_SIZE << order; + if (hugetlb_cma_percent) { + unsigned long orig_size = hugetlb_cma_size; + + hugetlb_cma_size = ALIGN_DOWN(hugetlb_cma_size, PAGE_SIZE << order); + if (orig_size && !hugetlb_cma_size) + pr_warn("hugetlb_cma: reservation size rounded down to 0 from %lu MiB (%u%%)\n", + orig_size / SZ_1M, hugetlb_cma_percent); + } else if (has_node_specific_param) { + hugetlb_cma_size = 0; + for (nid = 0; nid < MAX_NUMNODES; nid++) { + if (hugetlb_cma_percent_in_node[nid]) { + unsigned long orig_size = hugetlb_cma_size_in_node[nid]; + + hugetlb_cma_size_in_node[nid] = + ALIGN_DOWN(hugetlb_cma_size_in_node[nid], + PAGE_SIZE << order); + if (orig_size && !hugetlb_cma_size_in_node[nid]) + pr_warn("hugetlb_cma: reservation size rounded down to 0 from %lu MiB (%u%%) on node %d\n", + orig_size / SZ_1M, + hugetlb_cma_percent_in_node[nid], + nid); + } + hugetlb_cma_size += hugetlb_cma_size_in_node[nid]; + } + } + hugetlb_bootmem_set_nodes(); for (nid = 0; nid < MAX_NUMNODES; nid++) { @@ -194,8 +311,13 @@ void __init hugetlb_cma_reserve(void) per_node = DIV_ROUND_UP(hugetlb_cma_size, nodes_weight(hugetlb_bootmem_nodes)); per_node = round_up(per_node, gigantic_page_size); - pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", - hugetlb_cma_size / SZ_1M, per_node / SZ_1M); + if (hugetlb_cma_percent) + pr_info("hugetlb_cma: reserve %lu MiB (%u%%), up to %lu MiB per node\n", + hugetlb_cma_size / SZ_1M, hugetlb_cma_percent, + per_node / SZ_1M); + else + pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n", + hugetlb_cma_size / SZ_1M, per_node / SZ_1M); } reserved = 0; @@ -230,8 +352,12 @@ void __init hugetlb_cma_reserve(void) } reserved += size; - pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", - size / SZ_1M, nid); + if (hugetlb_cma_percent_in_node[nid]) + pr_info("hugetlb_cma: reserved %lu MiB (%u%%) on node %d\n", + size / SZ_1M, hugetlb_cma_percent_in_node[nid], nid); + else + pr_info("hugetlb_cma: reserved %lu MiB on node %d\n", + size / SZ_1M, nid); if (reserved >= hugetlb_cma_size) break; _ Patches currently in -mm which might be from souravpanda@google.com are mm-hugetlb_cma-fix-null-nodemask-dereference-in-hugetlb_cma_alloc_frozen_folio.patch