mm: vmscan: move shrinker-related code into a separate file

The mm/vmscan.c file is too large, so separate the shrinker-related code
from it into a separate file.  No functional changes.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Qi Zheng <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Christian König <[email protected]>
Cc: Chuck Lever <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Joel Fernandes <[email protected]>
Cc: Kirill Tkhai <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Steven Price <[email protected]>
Cc: Theodore Ts'o <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Abhinav Kumar <[email protected]>
Cc: Alasdair Kergon <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alyssa Rosenzweig <[email protected]>
Cc: Andreas Dilger <[email protected]>
Cc: Andreas Gruenbacher <[email protected]>
Cc: Anna Schumaker <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Bob Peterson <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Carlos Llamas <[email protected]>
Cc: Chandan Babu R <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Coly Li <[email protected]>
Cc: Dai Ngo <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Airlie <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: David Sterba <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Gao Xiang <[email protected]>
Cc: Huang Rui <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Jani Nikula <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jeffle Xu <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Marijn Suijten <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Mike Snitzer <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Nadav Amit <[email protected]>
Cc: Neil Brown <[email protected]>
Cc: Oleksandr Tyshchenko <[email protected]>
Cc: Olga Kornievskaia <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tomeu Vizoso <[email protected]>
Cc: Tom Talpey <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Tvrtko Ursulin <[email protected]>
Cc: Xuan Zhuo <[email protected]>
Cc: Yue Hu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: Qi Zheng

mm/Makefile

@@ -48,8 +48,8 @@ endif
 
 obj-y			:= filemap.o mempool.o oom_kill.o fadvise.o \
 			   maccess.o page-writeback.o folio-compat.o \
-			   readahead.o swap.o truncate.o vmscan.o shmem.o \
-			   util.o mmzone.o vmstat.o backing-dev.o \
+			   readahead.o swap.o truncate.o vmscan.o shrinker.o \
+			   shmem.o util.o mmzone.o vmstat.o backing-dev.o \
 			   mm_init.o percpu.o slab_common.o \
 			   compaction.o show_mem.o shmem_quota.o\
 			   interval_tree.o list_lru.o workingset.o \

mm/internal.h

@@ -1156,6 +1156,8 @@ struct vma_prepare {
 };
 
 /* shrinker related functions */
+unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
+			  int priority);
 
 #ifdef CONFIG_SHRINKER_DEBUG
 extern int shrinker_debugfs_add(struct shrinker *shrinker);