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authorChao Yu <yuchao0@huawei.com>2017-08-07 23:09:56 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2017-08-21 15:55:07 -0700
commit969d1b180d987c2be02de890d0fff0f66a0e80de (patch)
tree0e5f7dcc846d75bf54ad3205c50c85180c7f93ae /fs/f2fs/sysfs.c
parentf24b150a63b208f4437efc7dc7a42954363641ca (diff)
f2fs: introduce discard_granularity sysfs entry
Commit d618ebaf0aa8 ("f2fs: enable small discard by default") enables f2fs to issue 4K size discard in real-time discard mode. However, issuing smaller discard may cost more lifetime but releasing less free space in flash device. Since f2fs has ability of separating hot/cold data and garbage collection, we can expect that small-sized invalid region would expand soon with OPU, deletion or garbage collection on valid datas, so it's better to delay or skip issuing smaller size discards, it could help to reduce overmuch consumption of IO bandwidth and lifetime of flash storage. This patch makes f2fs selectng 64K size as its default minimal granularity, and issue discard with the size which is not smaller than minimal granularity. Also it exposes discard granularity as sysfs entry for configuration in different scenario. Jaegeuk Kim: We must issue all the accumulated discard commands when fstrim is called. So, I've added pend_list_tag[] to indicate whether we should issue the commands or not. If tag sets P_ACTIVE or P_TRIM, we have to issue them. P_TRIM is set once at a time, given fstrim trigger. In addition, issue_discard_thread is calling too much due to the number of discard commands remaining in the pending list. I added a timer to control it likewise gc_thread. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/sysfs.c')
-rw-r--r--fs/f2fs/sysfs.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index c40e5d24df9f..4bcaa9059026 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -152,6 +152,27 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
spin_unlock(&sbi->stat_lock);
return count;
}
+
+ if (!strcmp(a->attr.name, "discard_granularity")) {
+ struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
+ int i;
+
+ if (t == 0 || t > MAX_PLIST_NUM)
+ return -EINVAL;
+ if (t == *ui)
+ return count;
+
+ mutex_lock(&dcc->cmd_lock);
+ for (i = 0; i < MAX_PLIST_NUM; i++) {
+ if (i >= t - 1)
+ dcc->pend_list_tag[i] |= P_ACTIVE;
+ else
+ dcc->pend_list_tag[i] &= (~P_ACTIVE);
+ }
+ mutex_unlock(&dcc->cmd_lock);
+ return count;
+ }
+
*ui = t;
if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0)
@@ -248,6 +269,7 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_urgent, gc_urgent);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);
+F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);
F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
@@ -290,6 +312,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(gc_urgent),
ATTR_LIST(reclaim_segments),
ATTR_LIST(max_small_discards),
+ ATTR_LIST(discard_granularity),
ATTR_LIST(batched_trim_sections),
ATTR_LIST(ipu_policy),
ATTR_LIST(min_ipu_util),