erofs: introduce multipage per-CPU buffers
To deal the with the cases which inplace decompression is infeasible
for some inplace I/O. Per-CPU buffers was introduced to get rid of page
allocation latency and thrash for low-latency decompression algorithms
such as lz4.
For the big pcluster feature, introduce multipage per-CPU buffers to
keep such inplace I/O pclusters temporarily as well but note that
per-CPU pages are just consecutive virtually.
When a new big pcluster fs is mounted, its max pclustersize will be
read and per-CPU buffers can be growed if needed. Shrinking adjustable
per-CPU buffers is more complex (because we don't know if such size
is still be used), so currently just release them all when unloading.
Link: https://lore.kernel.org/r/20210409190630.19569-1-xiang@kernel.org
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 05b02f9..4db0854 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -197,9 +197,6 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
/* hard limit of pages per compressed cluster */
#define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
-#define EROFS_PCPUBUF_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
-#else
-#define EROFS_PCPUBUF_NR_PAGES 0
#endif /* !CONFIG_EROFS_FS_ZIP */
/* we strictly follow PAGE_SIZE and no buffer head yet */
@@ -405,24 +402,16 @@ int erofs_namei(struct inode *dir, struct qstr *name,
/* dir.c */
extern const struct file_operations erofs_dir_fops;
+/* pcpubuf.c */
+void *erofs_get_pcpubuf(unsigned int requiredpages);
+void erofs_put_pcpubuf(void *ptr);
+int erofs_pcpubuf_growsize(unsigned int nrpages);
+void erofs_pcpubuf_init(void);
+void erofs_pcpubuf_exit(void);
+
/* utils.c / zdata.c */
struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
-#if (EROFS_PCPUBUF_NR_PAGES > 0)
-void *erofs_get_pcpubuf(unsigned int pagenr);
-#define erofs_put_pcpubuf(buf) do { \
- (void)&(buf); \
- preempt_enable(); \
-} while (0)
-#else
-static inline void *erofs_get_pcpubuf(unsigned int pagenr)
-{
- return ERR_PTR(-EOPNOTSUPP);
-}
-
-#define erofs_put_pcpubuf(buf) do {} while (0)
-#endif
-
#ifdef CONFIG_EROFS_FS_ZIP
int erofs_workgroup_put(struct erofs_workgroup *grp);
struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,