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f2fs: Reduce zoned block device memory usage 

For zoned block devices, an array of zone types for each device is
allocated and initialized in order to determine if a section is stored
on a sequential zone (zone reset needed) or a conventional zone (no
zone reset needed and regular discard applies). Considering this usage,
the zone types stored in memory can be replaced with a bitmap to
indicate an equivalent information, that is, if a zone is sequential or
not. This reduces the memory usage for each zoned device by roughly 8:
on a 14TB disk with zones of 256 MB, the zone type array consumes
13x4KB pages while the bitmap uses only 2x4KB pages.

This patch changes the f2fs_dev_info structure blkz_type field to the
bitmap blkz_seq. Access to this bitmap is done using the helper
function f2fs_blkz_is_seq(), which is a rewrite of the function
get_blkz_type().

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
hifive-unleashed-5.2
Damien Le Moal 2019-03-16 09:13:07 +09:00 committed by Jaegeuk Kim
parent 0916878da3
commit 95175dafc4
3 changed files with 29 additions and 34 deletions
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14
fs/f2fs/f2fs.h
View File

@ -1068,8 +1068,8 @@ struct f2fs_dev_info {
block_t start_blk;
block_t end_blk;
#ifdef CONFIG_BLK_DEV_ZONED
unsigned int nr_blkz; /* Total number of zones */
u8 *blkz_type; /* Array of zones type */
unsigned int nr_blkz; /* Total number of zones */
unsigned long *blkz_seq; /* Bitmap indicating sequential zones */
#endif
};
@ -3542,16 +3542,12 @@ F2FS_FEATURE_FUNCS(lost_found, LOST_FOUND);
F2FS_FEATURE_FUNCS(sb_chksum, SB_CHKSUM);
#ifdef CONFIG_BLK_DEV_ZONED
static inline int get_blkz_type(struct f2fs_sb_info *sbi,
struct block_device *bdev, block_t blkaddr)
static inline bool f2fs_blkz_is_seq(struct f2fs_sb_info *sbi, int devi,
block_t blkaddr)
{
unsigned int zno = blkaddr >> sbi->log_blocks_per_blkz;
int i;
for (i = 0; i < sbi->s_ndevs; i++)
if (FDEV(i).bdev == bdev)
return FDEV(i).blkz_type[zno];
return -EINVAL;
return test_bit(zno, FDEV(devi).blkz_seq);
}
#endif

36
fs/f2fs/segment.c
View File

@ -1735,40 +1735,36 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
if (f2fs_is_multi_device(sbi)) {
devi = f2fs_target_device_index(sbi, blkstart);
if (blkstart < FDEV(devi).start_blk ||
blkstart > FDEV(devi).end_blk) {
f2fs_msg(sbi->sb, KERN_ERR, "Invalid block %x",
blkstart);
return -EIO;
}
blkstart -= FDEV(devi).start_blk;
}
/*
* We need to know the type of the zone: for conventional zones,
* use regular discard if the drive supports it. For sequential
* zones, reset the zone write pointer.
*/
switch (get_blkz_type(sbi, bdev, blkstart)) {
case BLK_ZONE_TYPE_CONVENTIONAL:
if (!blk_queue_discard(bdev_get_queue(bdev)))
return 0;
return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
case BLK_ZONE_TYPE_SEQWRITE_REQ:
case BLK_ZONE_TYPE_SEQWRITE_PREF:
/* For sequential zones, reset the zone write pointer */
if (f2fs_blkz_is_seq(sbi, devi, blkstart)) {
sector = SECTOR_FROM_BLOCK(blkstart);
nr_sects = SECTOR_FROM_BLOCK(blklen);
if (sector & (bdev_zone_sectors(bdev) - 1) ||
nr_sects != bdev_zone_sectors(bdev)) {
f2fs_msg(sbi->sb, KERN_INFO,
"(%d) %s: Unaligned discard attempted (block %x + %x)",
f2fs_msg(sbi->sb, KERN_ERR,
"(%d) %s: Unaligned zone reset attempted (block %x + %x)",
devi, sbi->s_ndevs ? FDEV(devi).path: "",
blkstart, blklen);
return -EIO;
}
trace_f2fs_issue_reset_zone(bdev, blkstart);
return blkdev_reset_zones(bdev, sector,
nr_sects, GFP_NOFS);
default:
/* Unknown zone type: broken device ? */
return -EIO;
return blkdev_reset_zones(bdev, sector, nr_sects, GFP_NOFS);
}
/* For conventional zones, use regular discard if supported */
if (!blk_queue_discard(bdev_get_queue(bdev)))
return 0;
return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
}
#endif

13
fs/f2fs/super.c
View File

@ -1024,7 +1024,7 @@ static void destroy_device_list(struct f2fs_sb_info *sbi)
for (i = 0; i < sbi->s_ndevs; i++) {
blkdev_put(FDEV(i).bdev, FMODE_EXCL);
#ifdef CONFIG_BLK_DEV_ZONED
kvfree(FDEV(i).blkz_type);
kvfree(FDEV(i).blkz_seq);
#endif
}
kvfree(sbi->devs);
@ -2798,9 +2798,11 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
if (nr_sectors & (bdev_zone_sectors(bdev) - 1))
FDEV(devi).nr_blkz++;
FDEV(devi).blkz_type = f2fs_kmalloc(sbi, FDEV(devi).nr_blkz,
GFP_KERNEL);
if (!FDEV(devi).blkz_type)
FDEV(devi).blkz_seq = f2fs_kzalloc(sbi,
BITS_TO_LONGS(FDEV(devi).nr_blkz)
* sizeof(unsigned long),
GFP_KERNEL);
if (!FDEV(devi).blkz_seq)
return -ENOMEM;
#define F2FS_REPORT_NR_ZONES 4096
@ -2827,7 +2829,8 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
}
for (i = 0; i < nr_zones; i++) {
FDEV(devi).blkz_type[n] = zones[i].type;
if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
set_bit(n, FDEV(devi).blkz_seq);
sector += zones[i].len;
n++;
}