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authorChao Yu <chao2.yu@samsung.com>2015-10-12 17:08:48 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2015-10-12 14:03:43 -0700
commitea1a29a0bdfffd56ca98335c0655308e8d7d0e22 (patch)
tree15cff3be22c03ada0cb3e5936b73ed1451645176
parent2db2388fcf0d880bd7160264274ed873baec4f0d (diff)
f2fs: export ra_nid_pages to sysfs
After finishing building free nid cache, we will try to readahead asynchronously 4 more pages for the next reloading, the count of readahead nid pages is fixed. In some case, like SMR drive, read less sectors with fixed count each time we trigger RA may be low efficient, since we will face high seeking overhead, so we'd better let user to configure this parameter from sysfs in specific workload. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
-rw-r--r--Documentation/ABI/testing/sysfs-fs-f2fs6
-rw-r--r--fs/f2fs/f2fs.h1
-rw-r--r--fs/f2fs/node.c3
-rw-r--r--fs/f2fs/node.h4
-rw-r--r--fs/f2fs/super.c2
5 files changed, 14 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index e066281dfd4e..0345f2d1c727 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -86,3 +86,9 @@ Date: October 2015
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description:
Controls the checkpoint timing.
+
+What: /sys/fs/f2fs/<disk>/ra_nid_pages
+Date: October 2015
+Contact: "Chao Yu" <chao2.yu@samsung.com>
+Description:
+ Controls the count of nid pages to be readaheaded.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5f372c03de32..94cf6bc1303f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -510,6 +510,7 @@ struct f2fs_nm_info {
nid_t available_nids; /* maximum available node ids */
nid_t next_scan_nid; /* the next nid to be scanned */
unsigned int ram_thresh; /* control the memory footprint */
+ unsigned int ra_nid_pages; /* # of nid pages to be readaheaded */
/* NAT cache management */
struct radix_tree_root nat_root;/* root of the nat entry cache */
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 14f46067817a..7bcbc6e9c40d 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1562,7 +1562,7 @@ static void build_free_nids(struct f2fs_sb_info *sbi)
mutex_unlock(&curseg->curseg_mutex);
ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid),
- FREE_NID_PAGES, META_NAT, false);
+ nm_i->ra_nid_pages, META_NAT, false);
}
/*
@@ -2005,6 +2005,7 @@ static int init_node_manager(struct f2fs_sb_info *sbi)
nm_i->fcnt = 0;
nm_i->nat_cnt = 0;
nm_i->ram_thresh = DEF_RAM_THRESHOLD;
+ nm_i->ra_nid_pages = DEF_RA_NID_PAGES;
INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
INIT_LIST_HEAD(&nm_i->free_nid_list);
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index 7427e956ad81..e4fffd2d98c4 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -14,9 +14,11 @@
/* node block offset on the NAT area dedicated to the given start node id */
#define NAT_BLOCK_OFFSET(start_nid) (start_nid / NAT_ENTRY_PER_BLOCK)
-/* # of pages to perform readahead before building free nids */
+/* # of pages to perform synchronous readahead before building free nids */
#define FREE_NID_PAGES 4
+#define DEF_RA_NID_PAGES 4 /* # of nid pages to be readaheaded */
+
/* maximum readahead size for node during getting data blocks */
#define MAX_RA_NODE 128
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index cb23d85a4ed3..3a65e0132352 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -213,6 +213,7 @@ F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
+F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ra_nid_pages, ra_nid_pages);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, cp_interval);
@@ -232,6 +233,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(max_victim_search),
ATTR_LIST(dir_level),
ATTR_LIST(ram_thresh),
+ ATTR_LIST(ra_nid_pages),
ATTR_LIST(cp_interval),
NULL,
};