From 3bcebc5bac0935d662f30d317e33ffa660bebf93 Mon Sep 17 00:00:00 2001 From: Hans Holmberg Date: Tue, 11 Dec 2018 20:16:13 +0100 Subject: lightnvm: pblk: set conservative threshold for user writes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Javier González Signed-off-by: Matias Bjørling Signed-off-by: Jens Axboe --- drivers/lightnvm/pblk-rl.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/lightnvm/pblk-rl.c') diff --git a/drivers/lightnvm/pblk-rl.c b/drivers/lightnvm/pblk-rl.c index db55a1c89997..76116d5f78e4 100644 --- a/drivers/lightnvm/pblk-rl.c +++ b/drivers/lightnvm/pblk-rl.c @@ -214,11 +214,10 @@ void pblk_rl_init(struct pblk_rl *rl, int budget) struct nvm_geo *geo = &dev->geo; struct pblk_line_mgmt *l_mg = &pblk->l_mg; struct pblk_line_meta *lm = &pblk->lm; - int min_blocks = lm->blk_per_line * PBLK_GC_RSV_LINE; int sec_meta, blk_meta; - unsigned int rb_windows; + /* Consider sectors used for metadata */ sec_meta = (lm->smeta_sec + lm->emeta_sec[0]) * l_mg->nr_free_lines; blk_meta = DIV_ROUND_UP(sec_meta, geo->clba); @@ -226,7 +225,7 @@ void pblk_rl_init(struct pblk_rl *rl, int budget) rl->high = pblk->op_blks - blk_meta - lm->blk_per_line; rl->high_pw = get_count_order(rl->high); - rl->rsv_blocks = min_blocks; + rl->rsv_blocks = pblk_get_min_chks(pblk); /* This will always be a power-of-2 */ rb_windows = budget / NVM_MAX_VLBA; -- cgit v1.2.3