Mailing List Archive

[PATCH 02/10] um: Fix MAX_ORDER usage in linux_main()
MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
can deliver is MAX_ORDER-1.

Fix MAX_ORDER usage in linux_main().

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
---
arch/um/kernel/um_arch.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 8dcda617b8bf..5e5a9c8e0e5d 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -368,10 +368,10 @@ int __init linux_main(int argc, char **argv)
max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;

/*
- * Zones have to begin on a 1 << MAX_ORDER page boundary,
+ * Zones have to begin on a 1 << MAX_ORDER-1 page boundary,
* so this makes sure that's true for highmem
*/
- max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
+ max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER - 1)) - 1);
if (physmem_size + iomem_size > max_physmem) {
highmem = physmem_size + iomem_size - max_physmem;
physmem_size -= highmem;
--
2.39.2
Re: [PATCH 02/10] um: Fix MAX_ORDER usage in linux_main() [ In reply to ]
On Wed, Mar 15, 2023 at 02:31:25PM +0300, Kirill A. Shutemov wrote:
> MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
> can deliver is MAX_ORDER-1.
>
> Fix MAX_ORDER usage in linux_main().
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
> Cc: Johannes Berg <johannes@sipsolutions.net>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> arch/um/kernel/um_arch.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
> index 8dcda617b8bf..5e5a9c8e0e5d 100644
> --- a/arch/um/kernel/um_arch.c
> +++ b/arch/um/kernel/um_arch.c
> @@ -368,10 +368,10 @@ int __init linux_main(int argc, char **argv)
> max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
>
> /*
> - * Zones have to begin on a 1 << MAX_ORDER page boundary,
> + * Zones have to begin on a 1 << MAX_ORDER-1 page boundary,
> * so this makes sure that's true for highmem
> */
> - max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
> + max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER - 1)) - 1);
> if (physmem_size + iomem_size > max_physmem) {
> highmem = physmem_size + iomem_size - max_physmem;
> physmem_size -= highmem;
> --
> 2.39.2
>

--
Sincerely yours,
Mike.
Re: [PATCH 02/10] um: Fix MAX_ORDER usage in linux_main() [ In reply to ]
On 3/15/23 12:31, Kirill A. Shutemov wrote:
> MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
> can deliver is MAX_ORDER-1.
>
> Fix MAX_ORDER usage in linux_main().
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> Cc: Richard Weinberger <richard@nod.at>
> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
> Cc: Johannes Berg <johannes@sipsolutions.net>
> ---
> arch/um/kernel/um_arch.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
> index 8dcda617b8bf..5e5a9c8e0e5d 100644
> --- a/arch/um/kernel/um_arch.c
> +++ b/arch/um/kernel/um_arch.c
> @@ -368,10 +368,10 @@ int __init linux_main(int argc, char **argv)
> max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
>
> /*
> - * Zones have to begin on a 1 << MAX_ORDER page boundary,
> + * Zones have to begin on a 1 << MAX_ORDER-1 page boundary,
> * so this makes sure that's true for highmem
> */
> - max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
> + max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER - 1)) - 1);
> if (physmem_size + iomem_size > max_physmem) {
> highmem = physmem_size + iomem_size - max_physmem;
> physmem_size -= highmem;