* [RFC PATCH 14/15] mm: introduce MIN_MAX_ORDER to replace MAX_ORDER as compile time constant.
[not found] <20210805190253.2795604-1-zi.yan@sent.com>
@ 2021-08-05 19:02 ` Zi Yan
2021-08-08 8:23 ` Mike Rapoport
0 siblings, 1 reply; 3+ messages in thread
From: Zi Yan @ 2021-08-05 19:02 UTC (permalink / raw)
To: David Hildenbrand, linux-mm
Cc: linux-arm-kernel, Catalin Marinas, John Hubbard, linux-kernel,
Matthew Wilcox, Michal Hocko, Vlastimil Babka, Zi Yan,
Marc Zyngier, Christoph Lameter, kvmarm, Kirill A . Shutemov,
Mike Kravetz
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))
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
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [RFC PATCH 14/15] mm: introduce MIN_MAX_ORDER to replace MAX_ORDER as compile time constant.
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
2021-08-09 15:35 ` Zi Yan
0 siblings, 1 reply; 3+ messages in thread
From: Mike Rapoport @ 2021-08-08 8:23 UTC (permalink / raw)
To: Zi Yan
Cc: linux-arm-kernel, Catalin Marinas, David Hildenbrand,
John Hubbard, linux-kernel, Matthew Wilcox, Michal Hocko,
linux-mm, Vlastimil Babka, Marc Zyngier, Christoph Lameter,
kvmarm, Kirill A . Shutemov, Mike Kravetz
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.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC PATCH 14/15] mm: introduce MIN_MAX_ORDER to replace MAX_ORDER as compile time constant.
2021-08-08 8:23 ` Mike Rapoport
@ 2021-08-09 15:35 ` Zi Yan
0 siblings, 0 replies; 3+ messages in thread
From: Zi Yan @ 2021-08-09 15:35 UTC (permalink / raw)
To: Mike Rapoport
Cc: linux-arm-kernel, Catalin Marinas, David Hildenbrand,
John Hubbard, linux-kernel, Matthew Wilcox, Michal Hocko,
linux-mm, Vlastimil Babka, Marc Zyngier, Christoph Lameter,
kvmarm, Kirill A . Shutemov, Mike Kravetz
[-- Attachment #1.1: Type: text/plain, Size: 7917 bytes --]
On 8 Aug 2021, at 4:23, Mike Rapoport wrote:
> 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:
Just to clarify the use of #ifdef:
MAX_ORDER is changed to a boot time variable and it cannot be used
for static array declaration, so I added MIN_MAX_ORDER.
At the moment, there are three cases of setting MAX_ORDER and
MIN_MAX_ORDER:
1. CONFIG_ARCH_FORCE_MAX_ORDER tells the MAX_ORDER certain arch
needs at compilation time.
2. CONFIG_SET_MAX_ORDER allows to change MAX_ORDER when an arch
does not set its MAX_ORER and SPARSEMEM_VMEMMAP is set.
3. !SPARSEMEM_VMEMMAP and no CONFIG_ARCH_FORCE_MAX_ORDER, then
MAX_ORDER is set to 11 by default.
I agree the code is hard to read, I will clean this up.
>
> /* 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.
—
Best Regards,
Yan, Zi
[-- Attachment #1.2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 854 bytes --]
[-- Attachment #2: Type: text/plain, Size: 151 bytes --]
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-08-10 14:28 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20210805190253.2795604-1-zi.yan@sent.com>
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
2021-08-09 15:35 ` Zi Yan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox