diff options
| author | Hans Holmberg <hans.holmberg@cnexlabs.com> | 2018-12-11 22:16:13 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-11 22:22:33 +0300 |
| commit | 3bcebc5bac0935d662f30d317e33ffa660bebf93 (patch) | |
| tree | a253b85173c905425e6dc5bcdd285399faa2419f /drivers/lightnvm/pblk.h | |
| parent | 525f7bb2c9f9b2c6673854eade89e98fb3ba7802 (diff) | |
| download | linux-3bcebc5bac0935d662f30d317e33ffa660bebf93.tar.xz | |
lightnvm: pblk: set conservative threshold for user writes
In a worst-case scenario (random writes), OP% of sectors
in each line will be invalid, and we will then need
to move data out of 100/OP% lines to free a single line.
So, to prevent the possibility of running out of lines,
temporarily block user writes when there is less than
100/OP% free lines.
Also ensure that pblk creation does not produce instances
with insufficient over provisioning.
Insufficient over-provising is not a problem on real hardware,
but often an issue when running QEMU simulations (with few lines).
100 lines is enough to create a sane instance with the standard
(11%) over provisioning.
Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/lightnvm/pblk.h')
| -rw-r--r-- | drivers/lightnvm/pblk.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h index f415aae600c8..e5b88a25d4d6 100644 --- a/drivers/lightnvm/pblk.h +++ b/drivers/lightnvm/pblk.h @@ -905,7 +905,6 @@ int pblk_recov_check_emeta(struct pblk *pblk, struct line_emeta *emeta); #define PBLK_GC_MAX_READERS 8 /* Max number of outstanding GC reader jobs */ #define PBLK_GC_RQ_QD 128 /* Queue depth for inflight GC requests */ #define PBLK_GC_L_QD 4 /* Queue depth for inflight GC lines */ -#define PBLK_GC_RSV_LINE 1 /* Reserved lines for GC */ int pblk_gc_init(struct pblk *pblk); void pblk_gc_exit(struct pblk *pblk, bool graceful); @@ -1370,4 +1369,15 @@ static inline char *pblk_disk_name(struct pblk *pblk) return disk->disk_name; } + +static inline unsigned int pblk_get_min_chks(struct pblk *pblk) +{ + struct pblk_line_meta *lm = &pblk->lm; + /* In a worst-case scenario every line will have OP invalid sectors. + * We will then need a minimum of 1/OP lines to free up a single line + */ + + return DIV_ROUND_UP(100, pblk->op) * lm->blk_per_line; + +} #endif /* PBLK_H_ */ |