tmp_suning_uos_patched/include/linux/zsmalloc.h

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/*
* zsmalloc memory allocator
*
* Copyright (C) 2011 Nitin Gupta
* Copyright (C) 2012, 2013 Minchan Kim
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the license that better fits your requirements.
*
* Released under the terms of 3-clause BSD License
* Released under the terms of GNU General Public License Version 2.0
*/
#ifndef _ZS_MALLOC_H_
#define _ZS_MALLOC_H_
#include <linux/types.h>
/*
* zsmalloc mapping modes
*
* NOTE: These only make a difference when a mapped object spans pages.
* They also have no effect when ZSMALLOC_PGTABLE_MAPPING is selected.
*/
enum zs_mapmode {
ZS_MM_RW, /* normal read-write mapping */
ZS_MM_RO, /* read-only (no copy-out at unmap time) */
ZS_MM_WO /* write-only (no copy-in at map time) */
/*
* NOTE: ZS_MM_WO should only be used for initializing new
* (uninitialized) allocations. Partial writes to already
* initialized allocations should use ZS_MM_RW to preserve the
* existing data.
*/
};
struct zs_pool_stats {
/* How many pages were migrated (freed) */
unsigned long pages_compacted;
};
struct zs_pool;
struct zs_pool *zs_create_pool(const char *name);
void zs_destroy_pool(struct zs_pool *pool);
unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t flags);
void zs_free(struct zs_pool *pool, unsigned long obj);
zsmalloc: introduce zs_huge_class_size() Patch series "zsmalloc/zram: drop zram's max_zpage_size", v3. ZRAM's max_zpage_size is a bad thing. It forces zsmalloc to store normal objects as huge ones, which results in bigger zsmalloc memory usage. Drop it and use actual zsmalloc huge-class value when decide if the object is huge or not. This patch (of 2): Not every object can be share its zspage with other objects, e.g. when the object is as big as zspage or nearly as big a zspage. For such objects zsmalloc has a so called huge class - every object which belongs to huge class consumes the entire zspage (which consists of a physical page). On x86_64, PAGE_SHIFT 12 box, the first non-huge class size is 3264, so starting down from size 3264, objects can share page(-s) and thus minimize memory wastage. ZRAM, however, has its own statically defined watermark for huge objects, namely "3 * PAGE_SIZE / 4 = 3072", and forcibly stores every object larger than this watermark (3072) as a PAGE_SIZE object, in other words, to a huge class, while zsmalloc can keep some of those objects in non-huge classes. This results in increased memory consumption. zsmalloc knows better if the object is huge or not. Introduce zs_huge_class_size() function which tells if the given object can be stored in one of non-huge classes or not. This will let us to drop ZRAM's huge object watermark and fully rely on zsmalloc when we decide if the object is huge. [sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()] Link: http://lkml.kernel.org/r/20180314081833.1096-2-sergey.senozhatsky@gmail.com Link: http://lkml.kernel.org/r/20180306070639.7389-2-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-06 07:24:43 +08:00
size_t zs_huge_class_size(struct zs_pool *pool);
void *zs_map_object(struct zs_pool *pool, unsigned long handle,
enum zs_mapmode mm);
void zs_unmap_object(struct zs_pool *pool, unsigned long handle);
unsigned long zs_get_total_pages(struct zs_pool *pool);
zsmalloc: support compaction This patch provides core functions for migration of zsmalloc. Migraion policy is simple as follows. for each size class { while { src_page = get zs_page from ZS_ALMOST_EMPTY if (!src_page) break; dst_page = get zs_page from ZS_ALMOST_FULL if (!dst_page) dst_page = get zs_page from ZS_ALMOST_EMPTY if (!dst_page) break; migrate(from src_page, to dst_page); } } For migration, we need to identify which objects in zspage are allocated to migrate them out. We could know it by iterating of freed objects in a zspage because first_page of zspage keeps free objects singly-linked list but it's not efficient. Instead, this patch adds a tag(ie, OBJ_ALLOCATED_TAG) in header of each object(ie, handle) so we could check whether the object is allocated easily. This patch adds another status bit in handle to synchronize between user access through zs_map_object and migration. During migration, we cannot move objects user are using due to data coherency between old object and new object. [akpm@linux-foundation.org: zsmalloc.c needs sched.h for cond_resched()] Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Juneho Choi <juno.choi@lge.com> Cc: Gunho Lee <gunho.lee@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-16 07:15:30 +08:00
unsigned long zs_compact(struct zs_pool *pool);
void zs_pool_stats(struct zs_pool *pool, struct zs_pool_stats *stats);
#endif