Re: [PATCH 10/13] lightnvm: pblk: Reduce L2P DRAM footprint

Matias Bjørling
2019-03-04T13:11:57Z

On 2/27/19 6:14 PM, Igor Konopko wrote:
> Currently L2P map size is calculated based on
> the total number of available sectors, which is
> redundant, since it contains some number of
> over provisioning (11% by default).
>
> The goal of this patch is to change this size
> to the real capacity and thus reduce the DRAM
> footprint significantly - with default op value
> it is approx. 110MB of DRAM less for every 1TB
> of pblk drive.
>
> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com>
> ---
> drivers/lightnvm/pblk-core.c | 8 ++++----
> drivers/lightnvm/pblk-init.c | 7 +++----
> drivers/lightnvm/pblk-read.c | 2 +-
> drivers/lightnvm/pblk-recovery.c | 2 +-
> drivers/lightnvm/pblk.h | 1 -
> 5 files changed, 9 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> index f48f2e77f770..2e424c0275c1 100644
> --- a/drivers/lightnvm/pblk-core.c
> +++ b/drivers/lightnvm/pblk-core.c
> @@ -2024,7 +2024,7 @@ void pblk_update_map(struct pblk *pblk, sector_t lba, struct ppa_addr ppa)
> struct ppa_addr ppa_l2p;
>
> /* logic error: lba out-of-bounds. Ignore update */
> - if (!(lba < pblk->rl.nr_secs)) {
> + if (!(lba < pblk->capacity)) {
> WARN(1, "pblk: corrupted L2P map request\n");
> return;
> }
> @@ -2064,7 +2064,7 @@ int pblk_update_map_gc(struct pblk *pblk, sector_t lba, struct ppa_addr ppa_new,
> #endif
>
> /* logic error: lba out-of-bounds. Ignore update */
> - if (!(lba < pblk->rl.nr_secs)) {
> + if (!(lba < pblk->capacity)) {
> WARN(1, "pblk: corrupted L2P map request\n");
> return 0;
> }
> @@ -2110,7 +2110,7 @@ void pblk_update_map_dev(struct pblk *pblk, sector_t lba,
> }
>
> /* logic error: lba out-of-bounds. Ignore update */
> - if (!(lba < pblk->rl.nr_secs)) {
> + if (!(lba < pblk->capacity)) {
> WARN(1, "pblk: corrupted L2P map request\n");
> return;
> }
> @@ -2168,7 +2168,7 @@ void pblk_lookup_l2p_rand(struct pblk *pblk, struct ppa_addr *ppas,
> lba = lba_list[i];
> if (lba != ADDR_EMPTY) {
> /* logic error: lba out-of-bounds. Ignore update */
> - if (!(lba < pblk->rl.nr_secs)) {
> + if (!(lba < pblk->capacity)) {
> WARN(1, "pblk: corrupted L2P map request\n");
> continue;
> }
> diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
> index e553105b7ba1..9913a4514eb6 100644
> --- a/drivers/lightnvm/pblk-init.c
> +++ b/drivers/lightnvm/pblk-init.c
> @@ -105,7 +105,7 @@ static size_t pblk_trans_map_size(struct pblk *pblk)
> if (pblk->addrf_len < 32)
> entry_size = 4;
>
> - return entry_size * pblk->rl.nr_secs;
> + return entry_size * pblk->capacity;
> }
>
> #ifdef CONFIG_NVM_PBLK_DEBUG
> @@ -175,7 +175,7 @@ static int pblk_l2p_init(struct pblk *pblk, bool factory_init)
>
> pblk_ppa_set_empty(&ppa);
>
> - for (i = 0; i < pblk->rl.nr_secs; i++)
> + for (i = 0; i < pblk->capacity; i++)
> pblk_trans_map_set(pblk, i, ppa);
>
> ret = pblk_l2p_recover(pblk, factory_init);
> @@ -706,7 +706,6 @@ static int pblk_set_provision(struct pblk *pblk, int nr_free_chks)
> * on user capacity consider only provisioned blocks
> */
> pblk->rl.total_blocks = nr_free_chks;
> - pblk->rl.nr_secs = nr_free_chks * geo->clba;
>
> /* Consider sectors used for metadata */
> sec_meta = (lm->smeta_sec + lm->emeta_sec[0]) * l_mg->nr_free_lines;
> @@ -1289,7 +1288,7 @@ static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
>
> pblk_info(pblk, "luns:%u, lines:%d, secs:%llu, buf entries:%u\n",
> geo->all_luns, pblk->l_mg.nr_lines,
> - (unsigned long long)pblk->rl.nr_secs,
> + (unsigned long long)pblk->capacity,
> pblk->rwb.nr_entries);
>
> wake_up_process(pblk->writer_ts);
> diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
> index 39c1d6ccaedb..65697463def8 100644
> --- a/drivers/lightnvm/pblk-read.c
> +++ b/drivers/lightnvm/pblk-read.c
> @@ -561,7 +561,7 @@ static int read_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
> goto out;
>
> /* logic error: lba out-of-bounds */
> - if (lba >= pblk->rl.nr_secs) {
> + if (lba >= pblk->capacity) {
> WARN(1, "pblk: read lba out of bounds\n");
> goto out;
> }
> diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
> index d86f580036d3..83b467b5edc7 100644
> --- a/drivers/lightnvm/pblk-recovery.c
> +++ b/drivers/lightnvm/pblk-recovery.c
> @@ -474,7 +474,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
>
> lba_list[paddr++] = cpu_to_le64(lba);
>
> - if (lba == ADDR_EMPTY || lba > pblk->rl.nr_secs)
> + if (lba == ADDR_EMPTY || lba >= pblk->capacity)
> continue;
>
> line->nr_valid_lbas++;
> diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
> index a6386d5acd73..a92377530930 100644
> --- a/drivers/lightnvm/pblk.h
> +++ b/drivers/lightnvm/pblk.h
> @@ -305,7 +305,6 @@ struct pblk_rl {
>
> struct timer_list u_timer;
>
> - unsigned long long nr_secs;
> unsigned long total_blocks;
>
> atomic_t free_blocks; /* Total number of free blocks (+ OP) */
>

Thanks Igor. Applied for 5.2. I've also updated the text a bit.