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 9D1CC2C324C for ; Thu, 5 Jun 2025 02:43:25 +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=1749091408; cv=none; b=hsZ2EFBYsFHF6ZhNVW18BukF2kHxytTsYgyxDFUC0Wbtqq78vnrrGL/t3zy9i4yMH7daGzuDxFsnVZdy857wt4wkdv8QEG2H6n1Pi8QsdK1lrFWpikmC8YOjmRPWiOYGY18saxEaS/s/YI08+5izne7evvdCjHozgH9lWNt2ip4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749091408; c=relaxed/simple; bh=e9M/V5FLRor05pEbmP2mKuGexiaBIlZ+dMakGu7Iilo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DauUP7e6cdRF6SaCw9zSQ2wjCG+0TnNt3/2dUs5z0TE6bdDnvF0GVJqe3G4wZWVQr/eimrU7A9bkModQ8DH50dmxfVpkrvNNzdEDOh7Ooej24KXPlvHr56hOUw7L+NdMsDougyw3GGhrvgLGTTk9vkzad+TWZC1loSaqpYob0wA= 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 3DC66169C; Wed, 4 Jun 2025 19:43:07 -0700 (PDT) Received: from [10.164.18.47] (a077893.blr.arm.com [10.164.18.47]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 561843F673; Wed, 4 Jun 2025 19:43:19 -0700 (PDT) Message-ID: Date: Thu, 5 Jun 2025 08:13:16 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm: rename CONFIG_PAGE_BLOCK_ORDER to CONFIG_PAGE_BLOCK_MAX_ORDER. To: Zi Yan , david@redhat.com Cc: Liam.Howlett@oracle.com, akpm@linux-foundation.org, isaacmanjarres@google.com, jyescas@google.com, kaleshsingh@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, masahiroy@kernel.org, mhocko@suse.com, minchan@kernel.org, rppt@kernel.org, surenb@google.com, tjmercier@google.com, vbabka@suse.cz, Oscar Salvador References: <20250604211427.1590859-1-ziy@nvidia.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250604211427.1590859-1-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/5/25 02:44, Zi Yan wrote: > The config is in fact an additional upper limit of pageblock_order, so > rename it to avoid confusion. > > Signed-off-by: Zi Yan > Acked-by: David Hildenbrand > Reviewed-by: Oscar Salvador > Acked-by: Juan Yescas LGTM. Reviewed-by: Anshuman Khandual > --- >>>From v1[1]: > 1. used a new name: PAGE_BLOCK_MAX_ORDER, > 2. added the missing PAGE_BLOCK_ORDER rename in mm/mm_init.c[2] > 3. dropped the Fixes tag. > > [1] https://lore.kernel.org/linux-mm/20250603154843.1565239-1-ziy@nvidia.com/ > [2] https://lore.kernel.org/linux-mm/202506042058.XgvABCE0-lkp@intel.com/ > > include/linux/mmzone.h | 14 +++++++------- > include/linux/pageblock-flags.h | 8 ++++---- > mm/Kconfig | 15 ++++++++------- > mm/mm_init.c | 2 +- > 4 files changed, 20 insertions(+), 19 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 283913d42d7b..5bec8b1d0e66 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -38,19 +38,19 @@ > #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 > +#ifndef CONFIG_PAGE_BLOCK_MAX_ORDER > +#define PAGE_BLOCK_MAX_ORDER MAX_PAGE_ORDER > #else > -#define PAGE_BLOCK_ORDER CONFIG_PAGE_BLOCK_ORDER > -#endif /* CONFIG_PAGE_BLOCK_ORDER */ > +#define PAGE_BLOCK_MAX_ORDER CONFIG_PAGE_BLOCK_MAX_ORDER > +#endif /* CONFIG_PAGE_BLOCK_MAX_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, > + * by the buddy allocator, has to be larger or equal to the PAGE_BLOCK_MAX_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 > +#if (PAGE_BLOCK_MAX_ORDER > MAX_PAGE_ORDER) > +#error MAX_PAGE_ORDER must be >= PAGE_BLOCK_MAX_ORDER > #endif > > /* > diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h > index e73a4292ef02..6297c6343c55 100644 > --- a/include/linux/pageblock-flags.h > +++ b/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, PAGE_BLOCK_ORDER) > +#define pageblock_order MIN_T(unsigned int, HUGETLB_PAGE_ORDER, PAGE_BLOCK_MAX_ORDER) > > #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ > > #elif defined(CONFIG_TRANSPARENT_HUGEPAGE) > > -#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_ORDER) > +#define pageblock_order MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_MAX_ORDER) > > #else /* CONFIG_TRANSPARENT_HUGEPAGE */ > > -/* If huge pages are not used, group by PAGE_BLOCK_ORDER */ > -#define pageblock_order PAGE_BLOCK_ORDER > +/* If huge pages are not used, group by PAGE_BLOCK_MAX_ORDER */ > +#define pageblock_order PAGE_BLOCK_MAX_ORDER > > #endif /* CONFIG_HUGETLB_PAGE */ > > diff --git a/mm/Kconfig b/mm/Kconfig > index 65089552e124..3afac26d3594 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1017,8 +1017,8 @@ config ARCH_FORCE_MAX_ORDER > # the default page block order is MAX_PAGE_ORDER (10) as per > # include/linux/mmzone.h. > # > -config PAGE_BLOCK_ORDER > - int "Page Block Order" > +config PAGE_BLOCK_MAX_ORDER > + int "Page Block Order Upper Limit" > range 1 10 if ARCH_FORCE_MAX_ORDER = 0 > default 10 if ARCH_FORCE_MAX_ORDER = 0 > range 1 ARCH_FORCE_MAX_ORDER if ARCH_FORCE_MAX_ORDER != 0 > @@ -1026,12 +1026,13 @@ config PAGE_BLOCK_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. > + them. The maximum size of the page block order is at least limited by > + ARCH_FORCE_MAX_ORDER/MAX_PAGE_ORDER. > > - This config allows overriding the default page block order when the > - page block order is required to be smaller than ARCH_FORCE_MAX_ORDER > - or MAX_PAGE_ORDER. > + This config adds a new upper limit of default page block > + order when the page block order is required to be smaller than > + ARCH_FORCE_MAX_ORDER/MAX_PAGE_ORDER or other limits > + (see include/linux/pageblock-flags.h for details). > > Reducing pageblock order can negatively impact THP generation > success rate. If your workloads use THP heavily, please use this > diff --git a/mm/mm_init.c b/mm/mm_init.c > index f2944748f526..02f41e2bdf60 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -1509,7 +1509,7 @@ static inline void setup_usemap(struct zone *zone) {} > /* Initialise the number of pages represented by NR_PAGEBLOCK_BITS */ > void __init set_pageblock_order(void) > { > - unsigned int order = PAGE_BLOCK_ORDER; > + unsigned int order = PAGE_BLOCK_MAX_ORDER; > > /* Check that pageblock_nr_pages has not already been setup */ > if (pageblock_order)