| Message ID | 20230315113133.11326-3-kirill.shutemov@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix confusion around MAX_ORDER | expand |
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 >
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;
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;
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(-)