From: Mike Rapoport <rppt@kernel.org>
To: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org, Matthew Wilcox <willy@infradead.org>,
Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Michal Hocko <mhocko@kernel.org>,
John Hubbard <jhubbard@nvidia.com>,
linux-kernel@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoph Lameter <cl@linux.com>,
Quentin Perret <qperret@google.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Subject: Re: [RFC PATCH 14/15] mm: introduce MIN_MAX_ORDER to replace MAX_ORDER as compile time constant.
Date: Sun, 8 Aug 2021 11:23:08 +0300 [thread overview]
Message-ID: <YQ+UbJtSWciIVqr4@kernel.org> (raw)
In-Reply-To: <20210805190253.2795604-15-zi.yan@sent.com>
On Thu, Aug 05, 2021 at 03:02:52PM -0400, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> For other MAX_ORDER uses (described below), there is no need or too much
> hassle to convert certain static array to dynamic ones. Add
> MIN_MAX_ORDER to serve as compile time constant in place of MAX_ORDER.
>
> ARM64 hypervisor maintains its own free page list and does not import
> any core kernel symbols, so soon-to-be runtime variable MAX_ORDER is not
> accessible in ARM64 hypervisor code. Also there is no need to allocating
> very large pages.
>
> In SLAB/SLOB/SLUB, 2-D array kmalloc_caches uses MAX_ORDER in its second
> dimension. It is too much hassle to allocate memory for kmalloc_caches
> before any proper memory allocator is set up.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Christoph Lameter <cl@linux.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Quentin Perret <qperret@google.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: kvmarm@lists.cs.columbia.edu
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> ---
> arch/arm64/kvm/hyp/include/nvhe/gfp.h | 2 +-
> arch/arm64/kvm/hyp/nvhe/page_alloc.c | 3 ++-
> include/linux/mmzone.h | 3 +++
> include/linux/slab.h | 8 ++++----
> mm/slab.c | 2 +-
> mm/slub.c | 7 ++++---
> 6 files changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/include/nvhe/gfp.h b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> index fb0f523d1492..c774b4a98336 100644
> --- a/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> +++ b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> @@ -16,7 +16,7 @@ struct hyp_pool {
> * API at EL2.
> */
> hyp_spinlock_t lock;
> - struct list_head free_area[MAX_ORDER];
> + struct list_head free_area[MIN_MAX_ORDER];
> phys_addr_t range_start;
> phys_addr_t range_end;
> unsigned short max_order;
> diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c
> index 41fc25bdfb34..a1cc1b648de0 100644
> --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c
> +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c
> @@ -226,7 +226,8 @@ int hyp_pool_init(struct hyp_pool *pool, u64 pfn, unsigned int nr_pages,
> int i;
>
> hyp_spin_lock_init(&pool->lock);
> - pool->max_order = min(MAX_ORDER, get_order(nr_pages << PAGE_SHIFT));
> +
> + pool->max_order = min(MIN_MAX_ORDER, get_order(nr_pages << PAGE_SHIFT));
> for (i = 0; i < pool->max_order; i++)
> INIT_LIST_HEAD(&pool->free_area[i]);
> pool->range_start = phys;
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index 09aafc05aef4..379dada82d4b 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -27,11 +27,14 @@
> #ifndef CONFIG_ARCH_FORCE_MAX_ORDER
> #ifdef CONFIG_SET_MAX_ORDER
> #define MAX_ORDER CONFIG_SET_MAX_ORDER
> +#define MIN_MAX_ORDER CONFIG_SET_MAX_ORDER
> #else
> #define MAX_ORDER 11
> +#define MIN_MAX_ORDER MAX_ORDER
> #endif /* CONFIG_SET_MAX_ORDER */
> #else
> #define MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
> +#define MIN_MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
> #endif /* CONFIG_ARCH_FORCE_MAX_ORDER */
> #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
The end result of this #ifdef explosion looks entirely unreadable:
/* Free memory management - zoned buddy allocator. */
#ifndef CONFIG_ARCH_FORCE_MAX_ORDER
#ifdef CONFIG_SET_MAX_ORDER
/* Defined in mm/page_alloc.c */
extern int buddy_alloc_max_order;
#define MAX_ORDER buddy_alloc_max_order
#define MIN_MAX_ORDER CONFIG_SET_MAX_ORDER
#else
#define MAX_ORDER 11
#define MIN_MAX_ORDER MAX_ORDER
#endif /* CONFIG_SET_MAX_ORDER */
#else
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/* Defined in mm/page_alloc.c */
extern int buddy_alloc_max_order;
#define MAX_ORDER buddy_alloc_max_order
#else
#define MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
#endif /* CONFIG_SPARSEMEM_VMEMMAP */
#define MIN_MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
#endif /* CONFIG_ARCH_FORCE_MAX_ORDER */
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 2c0d80cca6b8..d8747c158db6 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -244,8 +244,8 @@ static inline void __check_heap_object(const void *ptr, unsigned long n,
> * to do various tricks to work around compiler limitations in order to
> * ensure proper constant folding.
> */
> -#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
> - (MAX_ORDER + PAGE_SHIFT - 1) : 25)
> +#define KMALLOC_SHIFT_HIGH ((MIN_MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
> + (MIN_MAX_ORDER + PAGE_SHIFT - 1) : 25)
> #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
> #ifndef KMALLOC_SHIFT_LOW
> #define KMALLOC_SHIFT_LOW 5
> @@ -258,7 +258,7 @@ static inline void __check_heap_object(const void *ptr, unsigned long n,
> * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
> */
> #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
> -#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
> +#define KMALLOC_SHIFT_MAX (MIN_MAX_ORDER + PAGE_SHIFT - 1)
> #ifndef KMALLOC_SHIFT_LOW
> #define KMALLOC_SHIFT_LOW 3
> #endif
> @@ -271,7 +271,7 @@ static inline void __check_heap_object(const void *ptr, unsigned long n,
> * be allocated from the same page.
> */
> #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
> -#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
> +#define KMALLOC_SHIFT_MAX (MIN_MAX_ORDER + PAGE_SHIFT - 1)
> #ifndef KMALLOC_SHIFT_LOW
> #define KMALLOC_SHIFT_LOW 3
> #endif
> diff --git a/mm/slab.c b/mm/slab.c
> index d0f725637663..0041de8ec0e9 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -466,7 +466,7 @@ static int __init slab_max_order_setup(char *str)
> {
> get_option(&str, &slab_max_order);
> slab_max_order = slab_max_order < 0 ? 0 :
> - min(slab_max_order, MAX_ORDER - 1);
> + min(slab_max_order, MIN_MAX_ORDER - 1);
> slab_max_order_set = true;
>
> return 1;
> diff --git a/mm/slub.c b/mm/slub.c
> index b6c5205252eb..228e4a77c678 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -3564,8 +3564,9 @@ static inline int calculate_order(unsigned int size)
> /*
> * Doh this slab cannot be placed using slub_max_order.
> */
> - order = slab_order(size, 1, MAX_ORDER, 1);
> - if (order < MAX_ORDER)
> +
> + order = slab_order(size, 1, MIN_MAX_ORDER, 1);
> + if (order < MIN_MAX_ORDER)
> return order;
> return -ENOSYS;
> }
> @@ -4079,7 +4080,7 @@ __setup("slub_min_order=", setup_slub_min_order);
> static int __init setup_slub_max_order(char *str)
> {
> get_option(&str, (int *)&slub_max_order);
> - slub_max_order = min(slub_max_order, (unsigned int)MAX_ORDER - 1);
> + slub_max_order = min(slub_max_order, (unsigned int)MIN_MAX_ORDER - 1);
>
> return 1;
> }
> --
> 2.30.2
>
--
Sincerely yours,
Mike.
next prev parent reply other threads:[~2021-08-08 8:23 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-05 19:02 [RFC PATCH 00/15] Make MAX_ORDER adjustable as a kernel boot time parameter Zi Yan
2021-08-05 19:02 ` [RFC PATCH 01/15] arch: x86: remove MAX_ORDER exceeding SECTION_SIZE check for 32bit vdso Zi Yan
2021-08-05 19:02 ` [RFC PATCH 02/15] arch: mm: rename FORCE_MAX_ZONEORDER to ARCH_FORCE_MAX_ORDER Zi Yan
2021-08-05 19:02 ` [RFC PATCH 03/15] mm: check pfn validity when buddy allocator can merge pages across mem sections Zi Yan
2021-08-05 19:02 ` [RFC PATCH 04/15] mm: prevent pageblock size being larger than section size Zi Yan
2021-08-05 19:02 ` [RFC PATCH 05/15] mm/memory_hotplug: online pages at " Zi Yan
2021-08-05 19:02 ` [RFC PATCH 06/15] mm: use PAGES_PER_SECTION instead for mem_map_offset/next() Zi Yan
2021-08-05 19:02 ` [RFC PATCH 07/15] mm: hugetlb: use PAGES_PER_SECTION to check mem_map discontiguity Zi Yan
2021-08-05 19:02 ` [RFC PATCH 08/15] fs: proc: use PAGES_PER_SECTION for page offline checking period Zi Yan
2021-08-07 10:32 ` Mike Rapoport
2021-08-09 15:45 ` [RFC PATCH 08/15] " Zi Yan
2021-08-05 19:02 ` [RFC PATCH 09/15] virtio: virtio_mem: use PAGES_PER_SECTION instead of MAX_ORDER_NR_PAGES Zi Yan
2021-08-09 7:35 ` David Hildenbrand
2021-08-05 19:02 ` [RFC PATCH 10/15] virtio: virtio_balloon: " Zi Yan
2021-08-09 7:42 ` David Hildenbrand
2021-08-05 19:02 ` [RFC PATCH 11/15] mm/page_reporting: report pages at section size instead of MAX_ORDER Zi Yan
2021-08-09 7:25 ` David Hildenbrand
2021-08-09 14:12 ` Alexander Duyck
2021-08-09 15:08 ` Zi Yan
2021-08-09 16:51 ` Alexander Duyck
2021-08-09 14:08 ` Alexander Duyck
2021-08-05 19:02 ` [RFC PATCH 12/15] mm: Make MAX_ORDER of buddy allocator configurable via Kconfig SET_MAX_ORDER Zi Yan
2021-08-06 15:16 ` Vlastimil Babka
2021-08-06 15:23 ` Zi Yan
2021-08-05 19:02 ` [RFC PATCH 13/15] mm: convert MAX_ORDER sized static arrays to dynamic ones Zi Yan
2021-08-05 19:16 ` Christian König
2021-08-05 19:58 ` Zi Yan
2021-08-06 9:37 ` Christian König
2021-08-06 14:00 ` Zi Yan
2021-08-05 19:02 ` [RFC PATCH 14/15] mm: introduce MIN_MAX_ORDER to replace MAX_ORDER as compile time constant Zi Yan
2021-08-08 8:23 ` Mike Rapoport [this message]
2021-08-09 15:35 ` Zi Yan
2021-08-05 19:02 ` [RFC PATCH 15/15] mm: make MAX_ORDER a kernel boot time parameter Zi Yan
2021-08-06 15:36 ` [RFC PATCH 00/15] Make MAX_ORDER adjustable as " Vlastimil Babka
2021-08-06 16:16 ` David Hildenbrand
2021-08-06 16:54 ` Vlastimil Babka
2021-08-06 17:08 ` David Hildenbrand
2021-08-06 18:24 ` Zi Yan
2021-08-09 7:20 ` David Hildenbrand
2021-08-08 7:41 ` Mike Rapoport
2021-08-06 16:32 ` Vlastimil Babka
2021-08-06 17:19 ` Zi Yan
2021-08-06 20:27 ` Hugh Dickins
2021-08-06 21:26 ` Zi Yan
2021-08-09 4:04 ` Hugh Dickins
2021-08-07 1:10 ` Matthew Wilcox
2021-08-07 21:23 ` Matthew Wilcox
2021-08-09 4:29 ` Hugh Dickins
2021-08-09 11:22 ` Matthew Wilcox
2021-08-09 7:41 ` David Hildenbrand
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