Messages in this thread | | | Subject | Re: [PATCH 5/5] f2fs: do not __punch_discard_cmd in lfs mode | From | Chao Yu <> | Date | Fri, 13 Jul 2018 11:26:27 +0800 |
| |
On 2018/7/12 23:09, Yunlong Song wrote: > In lfs mode, it is better to submit and wait for discard of the > new_blkaddr's overall section, rather than punch it which makes > more small discards and is not friendly with flash alignment. And > f2fs does not have to wait discard of each new_blkaddr except for the > start_block of each section with this patch.
For non-zoned block device, unaligned discard can be allowed; and if synchronous discard is very slow, it will block block allocator here, rather than that, I prefer just punch 4k lba of discard entry for performance.
If you don't want to encounter this condition, I suggest issue large size discard more quickly.
Thanks,
> > Signed-off-by: Yunlong Song <yunlong.song@huawei.com> > --- > fs/f2fs/segment.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++----- > fs/f2fs/segment.h | 7 ++++- > 2 files changed, 75 insertions(+), 8 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index f6c20e0..bce321a 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -893,7 +893,19 @@ static void __remove_discard_cmd(struct f2fs_sb_info *sbi, > static void f2fs_submit_discard_endio(struct bio *bio) > { > struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private; > + struct f2fs_sb_info *sbi = F2FS_SB(dc->bdev->bd_super); > > + if (test_opt(sbi, LFS)) { > + unsigned int segno = GET_SEGNO(sbi, dc->lstart); > + unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); > + int cnt = (dc->len >> sbi->log_blocks_per_seg) / > + sbi->segs_per_sec; > + > + while (cnt--) { > + set_bit(secno, FREE_I(sbi)->discard_secmap); > + secno++; > + } > + } > dc->error = blk_status_to_errno(bio->bi_status); > dc->state = D_DONE; > complete_all(&dc->wait); > @@ -1349,8 +1361,15 @@ static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr) > dc = (struct discard_cmd *)f2fs_lookup_rb_tree(&dcc->root, > NULL, blkaddr); > if (dc) { > - if (dc->state == D_PREP) { > + if (dc->state == D_PREP && !test_opt(sbi, LFS)) > __punch_discard_cmd(sbi, dc, blkaddr); > + else if (dc->state == D_PREP && test_opt(sbi, LFS)) { > + struct discard_policy dpolicy; > + > + __init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1); > + __submit_discard_cmd(sbi, &dpolicy, dc); > + dc->ref++; > + need_wait = true; > } else { > dc->ref++; > need_wait = true; > @@ -2071,9 +2090,10 @@ static void get_new_segment(struct f2fs_sb_info *sbi, > unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg); > unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg); > unsigned int left_start = hint; > - bool init = true; > + bool init = true, check_discard = test_opt(sbi, LFS) ? true : false; > int go_left = 0; > int i; > + unsigned long *free_secmap; > > spin_lock(&free_i->segmap_lock); > > @@ -2084,11 +2104,25 @@ static void get_new_segment(struct f2fs_sb_info *sbi, > goto got_it; > } > find_other_zone: > - secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint); > + if (check_discard) { > + int entries = f2fs_bitmap_size(MAIN_SECS(sbi)) / sizeof(unsigned long); > + > + free_secmap = free_i->tmp_secmap; > + for (i = 0; i < entries; i++) > + free_secmap[i] = (!(free_i->free_secmap[i] ^ > + free_i->discard_secmap[i])) | free_i->free_secmap[i]; > + } else > + free_secmap = free_i->free_secmap; > + > + secno = find_next_zero_bit(free_secmap, MAIN_SECS(sbi), hint); > if (secno >= MAIN_SECS(sbi)) { > if (dir == ALLOC_RIGHT) { > - secno = find_next_zero_bit(free_i->free_secmap, > + secno = find_next_zero_bit(free_secmap, > MAIN_SECS(sbi), 0); > + if (secno >= MAIN_SECS(sbi) && check_discard) { > + check_discard = false; > + goto find_other_zone; > + } > f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi)); > } else { > go_left = 1; > @@ -2098,13 +2132,17 @@ static void get_new_segment(struct f2fs_sb_info *sbi, > if (go_left == 0) > goto skip_left; > > - while (test_bit(left_start, free_i->free_secmap)) { > + while (test_bit(left_start, free_secmap)) { > if (left_start > 0) { > left_start--; > continue; > } > - left_start = find_next_zero_bit(free_i->free_secmap, > + left_start = find_next_zero_bit(free_secmap, > MAIN_SECS(sbi), 0); > + if (left_start >= MAIN_SECS(sbi) && check_discard) { > + check_discard = false; > + goto find_other_zone; > + } > f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi)); > break; > } > @@ -2719,7 +2757,18 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > > *new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg); > > - f2fs_wait_discard_bio(sbi, *new_blkaddr); > + if (test_opt(sbi, LFS)) { > + unsigned int start_segno, secno; > + > + secno = GET_SEC_FROM_SEG(sbi, curseg->segno); > + start_segno = secno * sbi->segs_per_sec; > + if (*new_blkaddr == START_BLOCK(sbi, start_segno) && > + !test_bit(secno, FREE_I(sbi)->discard_secmap)) > + f2fs_wait_discard_bio(sbi, *new_blkaddr); > + f2fs_bug_on(sbi, !test_bit(secno, FREE_I(sbi)->discard_secmap)); > + } > + else > + f2fs_wait_discard_bio(sbi, *new_blkaddr); > > /* > * __add_sum_entry should be resided under the curseg_mutex > @@ -3648,10 +3697,21 @@ static int build_free_segmap(struct f2fs_sb_info *sbi) > if (!free_i->free_secmap) > return -ENOMEM; > > + free_i->discard_secmap = f2fs_kvmalloc(sbi, sec_bitmap_size, GFP_KERNEL); > + if (!free_i->discard_secmap) > + return -ENOMEM; > + > + free_i->tmp_secmap = f2fs_kvmalloc(sbi, sec_bitmap_size, GFP_KERNEL); > + if (!free_i->tmp_secmap) > + return -ENOMEM; > + > /* set all segments as dirty temporarily */ > memset(free_i->free_segmap, 0xff, bitmap_size); > memset(free_i->free_secmap, 0xff, sec_bitmap_size); > > + /* set all sections as discarded temporarily */ > + memset(free_i->discard_secmap, 0xff, sec_bitmap_size); > + > /* init free segmap information */ > free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi)); > free_i->free_segments = 0; > @@ -4047,6 +4107,8 @@ static void destroy_free_segmap(struct f2fs_sb_info *sbi) > SM_I(sbi)->free_info = NULL; > kvfree(free_i->free_segmap); > kvfree(free_i->free_secmap); > + kvfree(free_i->discard_secmap); > + kvfree(free_i->tmp_secmap); > kfree(free_i); > } > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > index 5049551..b37a909 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -259,6 +259,8 @@ struct free_segmap_info { > spinlock_t segmap_lock; /* free segmap lock */ > unsigned long *free_segmap; /* free segment bitmap */ > unsigned long *free_secmap; /* free section bitmap */ > + unsigned long *discard_secmap; /* discard section bitmap */ > + unsigned long *tmp_secmap; /* bitmap for temporal use */ > }; > > /* Notice: The order of dirty type is same with CURSEG_XXX in f2fs.h */ > @@ -453,8 +455,11 @@ static inline void __set_test_and_free(struct f2fs_sb_info *sbi, > next = find_next_bit(free_i->free_segmap, > start_segno + sbi->segs_per_sec, start_segno); > if (next >= start_segno + sbi->segs_per_sec) { > - if (test_and_clear_bit(secno, free_i->free_secmap)) > + if (test_and_clear_bit(secno, free_i->free_secmap)) { > free_i->free_sections++; > + if (test_opt(sbi, LFS)) > + clear_bit(secno, free_i->discard_secmap); > + } > } > } > skip_free: >
| |