linux/mm/shuffle.h
Kirill A. Shutemov 23baf831a3 mm, treewide: redefine MAX_ORDER sanely
MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.

This definition is counter-intuitive and lead to number of bugs all over
the kernel.

Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.

[kirill@shutemov.name: fix min() warning]
  Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[akpm@linux-foundation.org: fix another min_t warning]
[kirill@shutemov.name: fixups per Zi Yan]
  Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name
[akpm@linux-foundation.org: fix underlining in docs]
  Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:46 -07:00

53 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright(c) 2018 Intel Corporation. All rights reserved.
#ifndef _MM_SHUFFLE_H
#define _MM_SHUFFLE_H
#include <linux/jump_label.h>
#define SHUFFLE_ORDER MAX_ORDER
#ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR
DECLARE_STATIC_KEY_FALSE(page_alloc_shuffle_key);
extern void __shuffle_free_memory(pg_data_t *pgdat);
extern bool shuffle_pick_tail(void);
static inline void __meminit shuffle_free_memory(pg_data_t *pgdat)
{
if (!static_branch_unlikely(&page_alloc_shuffle_key))
return;
__shuffle_free_memory(pgdat);
}
extern void __shuffle_zone(struct zone *z);
static inline void __meminit shuffle_zone(struct zone *z)
{
if (!static_branch_unlikely(&page_alloc_shuffle_key))
return;
__shuffle_zone(z);
}
static inline bool is_shuffle_order(int order)
{
if (!static_branch_unlikely(&page_alloc_shuffle_key))
return false;
return order >= SHUFFLE_ORDER;
}
#else
static inline bool shuffle_pick_tail(void)
{
return false;
}
static inline void shuffle_free_memory(pg_data_t *pgdat)
{
}
static inline void shuffle_zone(struct zone *z)
{
}
static inline bool is_shuffle_order(int order)
{
return false;
}
#endif
#endif /* _MM_SHUFFLE_H */