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 CBFBE13A3F2 for ; Tue, 13 May 2025 23:30:50 +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=1747179050; cv=none; b=DY40KYaAtyxwVKJAceVTZkEwv0Gzi1fCpOfhdnoCnfOwqrbNzCql8CV+NVYHPdNdOEmkXPLPZK0Oy2sTLx8rPZXN7+s2rM963SEpSqLTNLQOmt81vFy3wDZb2qgwBLD0EaXztYy+qLwVfIB0yVqPDAhuEjxq8cAJO49SFQAysKE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747179050; c=relaxed/simple; bh=+EsWWnX1+eGoj/qS5rt82TyeZkrCKdt6qBilnDEnOAk=; h=Date:To:From:Subject:Message-Id; b=KVKfq4rEDmTD/N+n4bfZ9r1am2oxeMjSAUME+PIo3I04G2cZQqn5IB73JNg8nKXpnldG2tni+L6ha6mFHO4C50g7LjVwXp9MR+CosKC5GIGoY9WVqSWgBXQfWWal3Fc244neV/U/n5WZFe8L12oyX5ZaqM/tkOPi9b9JYdGtfWA= 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=ZOd0tpeo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ZOd0tpeo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3470CC4CEE4; Tue, 13 May 2025 23:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747179050; bh=+EsWWnX1+eGoj/qS5rt82TyeZkrCKdt6qBilnDEnOAk=; h=Date:To:From:Subject:From; b=ZOd0tpeot8Uk3kelaPo6MOgc7bWubNgTSbvQqf8BLTfeVyhSSnJ0hyq+ENV/hoE4l F5SSkhH2YYst3lcdslNkB47S9R5AlBu6DlK/P5nwcJ2AzoG35+Xgtc0WwNSX4jRayv swBWdqcA6xUQtbr3Ep8dG3Gmac9sOc14sFDLSMkM= Date: Tue, 13 May 2025 16:30:49 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,vbabka@suse.cz,surenb@google.com,rppt@kernel.org,minchan@kernel.org,lorenzo.stoakes@oracle.com,Liam.Howlett@oracle.com,david@redhat.com,jyescas@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-add-config_page_block_order-to-select-page-block-order.patch removed from -mm tree Message-Id: <20250513233050.3470CC4CEE4@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: add CONFIG_PAGE_BLOCK_ORDER to select page block order has been removed from the -mm tree. Its filename was mm-add-config_page_block_order-to-select-page-block-order.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Juan Yescas Subject: mm: add CONFIG_PAGE_BLOCK_ORDER to select page block order Date: Fri, 9 May 2025 18:02:26 -0700 Problem: On large page size configurations (16KiB, 64KiB), the CMA alignment requirement (CMA_MIN_ALIGNMENT_BYTES) increases considerably, and this causes the CMA reservations to be larger than necessary. This means that system will have less available MIGRATE_UNMOVABLE and MIGRATE_RECLAIMABLE page blocks since MIGRATE_CMA can't fallback to them. The CMA_MIN_ALIGNMENT_BYTES increases because it depends on MAX_PAGE_ORDER which depends on ARCH_FORCE_MAX_ORDER. The value of ARCH_FORCE_MAX_ORDER increases on 16k and 64k kernels. For example, in ARM, the CMA alignment requirement when: - CONFIG_ARCH_FORCE_MAX_ORDER default value is used - CONFIG_TRANSPARENT_HUGEPAGE is set: PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES ----------------------------------------------------------------------- 4KiB | 10 | 10 | 4KiB * (2 ^ 10) = 4MiB 16Kib | 11 | 11 | 16KiB * (2 ^ 11) = 32MiB 64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB There are some extreme cases for the CMA alignment requirement when: - CONFIG_ARCH_FORCE_MAX_ORDER maximum value is set - CONFIG_TRANSPARENT_HUGEPAGE is NOT set: - CONFIG_HUGETLB_PAGE is NOT set PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES ------------------------------------------------------------------------ 4KiB | 15 | 15 | 4KiB * (2 ^ 15) = 128MiB 16Kib | 13 | 13 | 16KiB * (2 ^ 13) = 128MiB 64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB This affects the CMA reservations for the drivers. If a driver in a 4KiB kernel needs 4MiB of CMA memory, in a 16KiB kernel, the minimal reservation has to be 32MiB due to the alignment requirements: reserved-memory { ... cma_test_reserve: cma_test_reserve { compatible = "shared-dma-pool"; size = <0x0 0x400000>; /* 4 MiB */ ... }; }; reserved-memory { ... cma_test_reserve: cma_test_reserve { compatible = "shared-dma-pool"; size = <0x0 0x2000000>; /* 32 MiB */ ... }; }; Solution: Add a new config CONFIG_PAGE_BLOCK_ORDER that allows to set the page block order in all the architectures. The maximum page block order will be given by ARCH_FORCE_MAX_ORDER. By default, CONFIG_PAGE_BLOCK_ORDER will have the same value that ARCH_FORCE_MAX_ORDER. This will make sure that current kernel configurations won't be affected by this change. It is a opt-in change. This patch will allow to have the same CMA alignment requirements for large page sizes (16KiB, 64KiB) as that in 4kb kernels by setting a lower pageblock_order. Tests: - Verified that HugeTLB pages work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. - Verified that Transparent Huge Pages work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. - Verified that dma-buf heaps allocations work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. Benchmarks: The benchmarks compare 16kb kernels with pageblock_order 10 and 7. The reason for the pageblock_order 7 is because this value makes the min CMA alignment requirement the same as that in 4kb kernels (2MB). - Perform 100K dma-buf heaps (/dev/dma_heap/system) allocations of SZ_8M, SZ_4M, SZ_2M, SZ_1M, SZ_64, SZ_8, SZ_4. Use simpleperf (https://developer.android.com/ndk/guides/simpleperf) to measure the # of instructions and page-faults on 16k kernels. The benchmark was executed 10 times. The averages are below: # instructions | #page-faults order 10 | order 7 | order 10 | order 7 -------------------------------------------------------- 13,891,765,770 | 11,425,777,314 | 220 | 217 14,456,293,487 | 12,660,819,302 | 224 | 219 13,924,261,018 | 13,243,970,736 | 217 | 221 13,910,886,504 | 13,845,519,630 | 217 | 221 14,388,071,190 | 13,498,583,098 | 223 | 224 13,656,442,167 | 12,915,831,681 | 216 | 218 13,300,268,343 | 12,930,484,776 | 222 | 218 13,625,470,223 | 14,234,092,777 | 219 | 218 13,508,964,965 | 13,432,689,094 | 225 | 219 13,368,950,667 | 13,683,587,37 | 219 | 225 ------------------------------------------------------------------- 13,803,137,433 | 13,131,974,268 | 220 | 220 Averages There were 4.85% #instructions when order was 7, in comparison with order 10. 13,803,137,433 - 13,131,974,268 = -671,163,166 (-4.86%) The number of page faults in order 7 and 10 were the same. These results didn't show any significant regression when the pageblock_order is set to 7 on 16kb kernels. - Run speedometer 3.1 (https://browserbench.org/Speedometer3.1/) 5 times on the 16k kernels with pageblock_order 7 and 10. order 10 | order 7 | order 7 - order 10 | (order 7 - order 10) % ------------------------------------------------------------------- 15.8 | 16.4 | 0.6 | 3.80% 16.4 | 16.2 | -0.2 | -1.22% 16.6 | 16.3 | -0.3 | -1.81% 16.8 | 16.3 | -0.5 | -2.98% 16.6 | 16.8 | 0.2 | 1.20% ------------------------------------------------------------------- 16.44 16.4 -0.04 -0.24% Averages The results didn't show any significant regression when the pageblock_order is set to 7 on 16kb kernels. Link: https://lkml.kernel.org/r/20250510010338.3978696-1-jyescas@google.com Signed-off-by: Juan Yescas Acked-by: Zi Yan Cc: Vlastimil Babka Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: David Hildenbrand Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Minchan Kim Signed-off-by: Andrew Morton --- include/linux/mmzone.h | 16 +++++++++++++++ include/linux/pageblock-flags.h | 8 +++---- mm/Kconfig | 31 ++++++++++++++++++++++++++++++ 3 files changed, 51 insertions(+), 4 deletions(-) --- a/include/linux/mmzone.h~mm-add-config_page_block_order-to-select-page-block-order +++ a/include/linux/mmzone.h @@ -37,6 +37,22 @@ #define NR_PAGE_ORDERS (MAX_PAGE_ORDER + 1) +/* Defines the order for the number of pages that have a migrate type. */ +#ifndef CONFIG_PAGE_BLOCK_ORDER +#define PAGE_BLOCK_ORDER MAX_PAGE_ORDER +#else +#define PAGE_BLOCK_ORDER CONFIG_PAGE_BLOCK_ORDER +#endif /* CONFIG_PAGE_BLOCK_ORDER */ + +/* + * The MAX_PAGE_ORDER, which defines the max order of pages to be allocated + * by the buddy allocator, has to be larger or equal to the PAGE_BLOCK_ORDER, + * which defines the order for the number of pages that can have a migrate type + */ +#if (PAGE_BLOCK_ORDER > MAX_PAGE_ORDER) +#error MAX_PAGE_ORDER must be >= PAGE_BLOCK_ORDER +#endif + /* * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed * costly to service. That is between allocation orders which should --- a/include/linux/pageblock-flags.h~mm-add-config_page_block_order-to-select-page-block-order +++ a/include/linux/pageblock-flags.h @@ -41,18 +41,18 @@ extern unsigned int pageblock_order; * Huge pages are a constant size, but don't exceed the maximum allocation * granularity. */ -#define pageblock_order MIN_T(unsigned int, HUGETLB_PAGE_ORDER, MAX_PAGE_ORDER) +#define pageblock_order MIN_T(unsigned int, HUGETLB_PAGE_ORDER, PAGE_BLOCK_ORDER) #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ #elif defined(CONFIG_TRANSPARENT_HUGEPAGE) -#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, MAX_PAGE_ORDER) +#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_ORDER) #else /* CONFIG_TRANSPARENT_HUGEPAGE */ -/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */ -#define pageblock_order MAX_PAGE_ORDER +/* If huge pages are not used, group by PAGE_BLOCK_ORDER */ +#define pageblock_order PAGE_BLOCK_ORDER #endif /* CONFIG_HUGETLB_PAGE */ --- a/mm/Kconfig~mm-add-config_page_block_order-to-select-page-block-order +++ a/mm/Kconfig @@ -1005,6 +1005,37 @@ config CMA_AREAS If unsure, leave the default value "8" in UMA and "20" in NUMA. +# +# Select this config option from the architecture Kconfig, if available, to set +# the max page order for physically contiguous allocations. +# +config ARCH_FORCE_MAX_ORDER + int + +# When ARCH_FORCE_MAX_ORDER is not defined, the default page block order is 10, +# as per include/linux/mmzone.h. +config PAGE_BLOCK_ORDER + int "Page Block Order" + range 1 10 if !ARCH_FORCE_MAX_ORDER + default 10 if !ARCH_FORCE_MAX_ORDER + range 1 ARCH_FORCE_MAX_ORDER if ARCH_FORCE_MAX_ORDER + default ARCH_FORCE_MAX_ORDER if ARCH_FORCE_MAX_ORDER + + help + The page block order refers to the power of two number of pages that + are physically contiguous and can have a migrate type associated to + them. The maximum size of the page block order is limited by + ARCH_FORCE_MAX_ORDER. + + This option allows overriding the default setting when the page + block order requires to be smaller than ARCH_FORCE_MAX_ORDER. + + Reducing pageblock order can negatively impact THP generation + successful rate. If your workloads uses THP heavily, please use this + option with caution. + + Don't change if unsure. + config MEM_SOFT_DIRTY bool "Track memory changes" depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS _ Patches currently in -mm which might be from jyescas@google.com are