From: Rakesh Pandit <rakesh@tuxera.com>
To: "Javier González" <jg@lightnvm.io>
Cc: "Matias Bjørling" <mb@lightnvm.io>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lightnvm: pblk: fix changing GC group list for a line
Date: Mon, 2 Oct 2017 14:43:44 +0300 [thread overview]
Message-ID: <20171002114344.GA3526@dhcp-216.srv.tuxera.com> (raw)
In-Reply-To: <5656C93D-F3DF-4054-906C-C27542D265CA@lightnvm.io>
On Mon, Oct 02, 2017 at 01:27:42PM +0200, Javier González wrote:
> > On 28 Sep 2017, at 16.40, Rakesh Pandit <rakesh@tuxera.com> wrote:
> >
> > pblk_line_gc_list seems to had a bug since the introduction of pblk in
> > getting GC list for a line. In b20ba1bc7 while redesigning GC
> > algorithm it was not fixed correctly. The problem is that even if
> > valid sector count (vsc) is less that mid_thrs (threshold for GC mid
> > list) it would always satisfy 'vsc < high_thrs' as high_thrs >
> > mid_thrs always.
> >
> > Fixes: a4bd217b4("lightnvm: physical block device (pblk) target")
> > Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
> > ---
> > drivers/lightnvm/pblk-core.c | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/lightnvm/pblk-core.c b/drivers/lightnvm/pblk-core.c
> > index 8150164..93a58ed 100644
> > --- a/drivers/lightnvm/pblk-core.c
> > +++ b/drivers/lightnvm/pblk-core.c
> > @@ -295,16 +295,16 @@ struct list_head *pblk_line_gc_list(struct pblk *pblk, struct pblk_line *line)
> > line->gc_group = PBLK_LINEGC_FULL;
> > move_list = &l_mg->gc_full_list;
> > }
> > - } else if (vsc < lm->high_thrs) {
> > - if (line->gc_group != PBLK_LINEGC_HIGH) {
> > - line->gc_group = PBLK_LINEGC_HIGH;
> > - move_list = &l_mg->gc_high_list;
> > - }
> > } else if (vsc < lm->mid_thrs) {
> > if (line->gc_group != PBLK_LINEGC_MID) {
> > line->gc_group = PBLK_LINEGC_MID;
> > move_list = &l_mg->gc_mid_list;
> > }
> > + } else if (vsc < lm->high_thrs) {
> > + if (line->gc_group != PBLK_LINEGC_HIGH) {
> > + line->gc_group = PBLK_LINEGC_HIGH;
> > + move_list = &l_mg->gc_high_list;
> > + }
> > } else if (vsc < line->sec_in_line) {
> > if (line->gc_group != PBLK_LINEGC_LOW) {
> > line->gc_group = PBLK_LINEGC_LOW;
> > --
> > 2.9.3
>
> You're right that the naming for high/mid/low was not updated when
> aligning vsc with GC thresholds. But the fix should be making high,
> being high, instead of reordering when moving into the GC bucket.
>
> Does it make sense to you?
Yes.
>
> diff --git i/drivers/lightnvm/pblk-init.c w/drivers/lightnvm/pblk-init.c
> index 7cf4b536d899..bc5c6cc12ad5 100644
> --- i/drivers/lightnvm/pblk-init.c
> +++ w/drivers/lightnvm/pblk-init.c
> @@ -675,8 +675,8 @@ static int pblk_lines_init(struct pblk *pblk)
> lm->blk_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
> lm->sec_bitmap_len = BITS_TO_LONGS(lm->sec_per_line) * sizeof(long);
> lm->lun_bitmap_len = BITS_TO_LONGS(geo->nr_luns) * sizeof(long);
> - lm->high_thrs = lm->sec_per_line / 2;
> - lm->mid_thrs = lm->sec_per_line / 4;
> + lm->high_thrs = lm->sec_per_line / 4;
> + lm->mid_thrs = lm->sec_per_line / 2;
> lm->meta_distance = (geo->nr_luns / 2) * pblk->min_write_pgs;
>
> /* Calculate necessary pages for smeta. See comment over struct
Regards,
next prev parent reply other threads:[~2017-10-02 11:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-28 14:40 Rakesh Pandit
2017-10-02 11:27 ` Javier González
2017-10-02 11:43 ` Rakesh Pandit [this message]
2017-10-02 11:44 ` Javier González
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