@@ -81,3 +81,17 @@ config EROFS_FS_ZIP
If you don't want to enable compression feature, say N.
+config EROFS_FS_CLUSTER_PAGE_LIMIT
+ int "EROFS Cluster Pages Hard Limit"
+ depends on EROFS_FS_ZIP
+ range 1 256
+ default "1"
+ help
+ Indicates maximum # of pages of a compressed
+ physical cluster.
+
+ For example, if files in a image were compressed
+ into 8k-unit, hard limit should not be configured
+ less than 2. Otherwise, the image will be refused
+ to mount on this kernel.
+
@@ -222,6 +222,12 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
return v;
}
#endif /* !CONFIG_SMP */
+
+/* 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 */
@@ -482,6 +488,21 @@ int erofs_namei(struct inode *dir, struct qstr *name,
extern const struct file_operations erofs_dir_fops;
/* utils.c */
+#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(-ENOTSUPP);
+}
+
+#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,
@@ -9,6 +9,18 @@
#include "internal.h"
#include <linux/pagevec.h>
+#if (EROFS_PCPUBUF_NR_PAGES > 0)
+static struct {
+ u8 data[PAGE_SIZE * EROFS_PCPUBUF_NR_PAGES];
+} ____cacheline_aligned_in_smp erofs_pcpubuf[NR_CPUS];
+
+void *erofs_get_pcpubuf(unsigned int pagenr)
+{
+ preempt_disable();
+ return &erofs_pcpubuf[smp_processor_id()].data[pagenr * PAGE_SIZE];
+}
+#endif
+
#ifdef CONFIG_EROFS_FS_ZIP
/* global shrink count (for all mounted EROFS instances) */
static atomic_long_t erofs_global_shrink_cnt;
This patch introduces per-CPU buffers in order for the upcoming generic decompression framework to use. Note that I tried to use in-kernel per-CPU buffer or per-CPU page approaches to clean up further, however noticeable performanace regression (about 2% for sequential read) was observed. Let's leave it as-is for now. Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> --- fs/erofs/Kconfig | 14 ++++++++++++++ fs/erofs/internal.h | 21 +++++++++++++++++++++ fs/erofs/utils.c | 12 ++++++++++++ 3 files changed, 47 insertions(+)