Hi Jaegeuk, Any comments on other patches in this patchset?
Thanks, On 2017/9/19 23:30, Chao Yu wrote: > From: Chao Yu <[email protected]> > > This patch wraps scattered optional parameters into discard policy as > below, later, with it we expect that we can adjust these parameters with > proper strategy in different scenario. > > struct discard_policy { > unsigned int min_interval; /* used for candidates exist */ > unsigned int max_interval; /* used for candidates not exist */ > unsigned int max_requests; /* # of discards issued per round */ > unsigned int io_aware_gran; /* minimum granularity discard not be > aware of I/O */ > bool io_aware; /* issue discard in idle time */ > bool sync; /* submit discard with REQ_SYNC flag */ > }; > > This patch doesn't change any logic of codes. > > Signed-off-by: Chao Yu <[email protected]> > --- > fs/f2fs/f2fs.h | 12 +++++++++++- > fs/f2fs/segment.c | 38 +++++++++++++++++++++++++++++--------- > 2 files changed, 40 insertions(+), 10 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index cb13c7df6971..b119104e75bd 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -149,7 +149,7 @@ enum { > #define BATCHED_TRIM_BLOCKS(sbi) \ > (BATCHED_TRIM_SEGMENTS(sbi) << (sbi)->log_blocks_per_seg) > #define MAX_DISCARD_BLOCKS(sbi) BLKS_PER_SEC(sbi) > -#define DISCARD_ISSUE_RATE 8 > +#define DEF_MAX_DISCARD_REQUEST 8 /* issue 8 discards per > round */ > #define DEF_MIN_DISCARD_ISSUE_TIME 50 /* 50 ms, if exists */ > #define DEF_MAX_DISCARD_ISSUE_TIME 60000 /* 60 s, if no candidates */ > #define DEF_CP_INTERVAL 60 /* 60 secs */ > @@ -243,6 +243,15 @@ struct discard_cmd { > int error; /* bio error */ > }; > > +struct discard_policy { > + unsigned int min_interval; /* used for candidates exist */ > + unsigned int max_interval; /* used for candidates not exist */ > + unsigned int max_requests; /* # of discards issued per round */ > + unsigned int io_aware_gran; /* minimum granularity discard not be > aware of I/O */ > + bool io_aware; /* issue discard in idle time */ > + bool sync; /* submit discard with REQ_SYNC flag */ > +}; > + > struct discard_cmd_control { > struct task_struct *f2fs_issue_discard; /* discard thread */ > struct list_head entry_list; /* 4KB discard entry list */ > @@ -261,6 +270,7 @@ struct discard_cmd_control { > atomic_t issing_discard; /* # of issing discard */ > atomic_t discard_cmd_cnt; /* # of cached cmd count */ > struct rb_root root; /* root of discard rb-tree */ > + struct discard_policy dpolicy; /* current discard policy */ > }; > > /* for the list of fsync inodes, used only during recovery */ > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 088936c61905..b3787ba1108f 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -851,6 +851,7 @@ static void __submit_discard_cmd(struct f2fs_sb_info *sbi, > struct list_head *wait_list = fstrim ? &(dcc->fstrim_list) : > &(dcc->wait_list); > struct bio *bio = NULL; > + int flag = dcc->dpolicy.sync ? REQ_SYNC : 0; > > if (dc->state != D_PREP) > return; > @@ -869,7 +870,7 @@ static void __submit_discard_cmd(struct f2fs_sb_info *sbi, > if (bio) { > bio->bi_private = dc; > bio->bi_end_io = f2fs_submit_discard_endio; > - bio->bi_opf |= REQ_SYNC; > + bio->bi_opf |= flag; > submit_bio(bio); > list_move_tail(&dc->list, wait_list); > __check_sit_bitmap(sbi, dc->start, dc->start + dc->len); > @@ -1064,6 +1065,7 @@ static void __issue_discard_cmd_range(struct > f2fs_sb_info *sbi, > struct discard_cmd *prev_dc = NULL, *next_dc = NULL; > struct rb_node **insert_p = NULL, *insert_parent = NULL; > struct discard_cmd *dc; > + struct discard_policy *dpolicy = &dcc->dpolicy; > struct blk_plug plug; > int issued; > > @@ -1096,7 +1098,7 @@ static void __issue_discard_cmd_range(struct > f2fs_sb_info *sbi, > > __submit_discard_cmd(sbi, dc, true); > > - if (++issued >= DISCARD_ISSUE_RATE) { > + if (++issued >= dpolicy->max_requests) { > start = dc->lstart + dc->len; > > blk_finish_plug(&plug); > @@ -1124,6 +1126,7 @@ static int __issue_discard_cmd(struct f2fs_sb_info > *sbi, bool issue_cond) > struct list_head *pend_list; > struct discard_cmd *dc, *tmp; > struct blk_plug plug; > + struct discard_policy *dpolicy = &dcc->dpolicy; > int iter = 0, issued = 0; > int i; > bool io_interrupted = false; > @@ -1151,14 +1154,16 @@ static int __issue_discard_cmd(struct f2fs_sb_info > *sbi, bool issue_cond) > continue; > } > > - if (is_idle(sbi)) { > - __submit_discard_cmd(sbi, dc, false); > - issued++; > - } else { > + if (dpolicy->io_aware && i < dpolicy->io_aware_gran && > + !is_idle(sbi)) { > io_interrupted = true; > + goto skip; > } > > - if (++iter >= DISCARD_ISSUE_RATE) > + __submit_discard_cmd(sbi, dc, false); > + issued++; > +skip: > + if (++iter >= dpolicy->max_requests) > goto out; > } > if (list_empty(pend_list) && dcc->pend_list_tag[i] & P_TRIM) > @@ -1307,6 +1312,7 @@ static int issue_discard_thread(void *data) > struct f2fs_sb_info *sbi = data; > struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info; > wait_queue_head_t *q = &dcc->discard_wait_queue; > + struct discard_policy *dpolicy = &dcc->dpolicy; > unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME; > int issued; > > @@ -1333,9 +1339,9 @@ static int issue_discard_thread(void *data) > issued = __issue_discard_cmd(sbi, true); > if (issued) { > __wait_all_discard_cmd(sbi, true); > - wait_ms = DEF_MIN_DISCARD_ISSUE_TIME; > + wait_ms = dpolicy->min_interval; > } else { > - wait_ms = DEF_MAX_DISCARD_ISSUE_TIME; > + wait_ms = dpolicy->max_interval; > } > > sb_end_intwrite(sbi->sb); > @@ -1620,6 +1626,18 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, > struct cp_control *cpc) > wake_up_discard_thread(sbi, false); > } > > +static void inline init_discard_policy(struct discard_cmd_control *dcc) > +{ > + struct discard_policy *dpolicy = &dcc->dpolicy; > + > + dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME; > + dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME; > + dpolicy->max_requests = DEF_MAX_DISCARD_REQUEST; > + dpolicy->io_aware_gran = MAX_PLIST_NUM; > + dpolicy->io_aware = true; > + dpolicy->sync = true; > +} > + > static int create_discard_cmd_control(struct f2fs_sb_info *sbi) > { > dev_t dev = sbi->sb->s_bdev->bd_dev; > @@ -1653,6 +1671,8 @@ static int create_discard_cmd_control(struct > f2fs_sb_info *sbi) > dcc->undiscard_blks = 0; > dcc->root = RB_ROOT; > > + init_discard_policy(dcc); > + > init_waitqueue_head(&dcc->discard_wait_queue); > SM_I(sbi)->dcc_info = dcc; > init_thread: >
