diff mbox

lightnvm: pblk: fix changing GC group list for a line

Message ID 5656C93D-F3DF-4054-906C-C27542D265CA@lightnvm.io (mailing list archive)
State New, archived
Headers show

Commit Message

=?UTF-8?q?Javier=20Gonz=C3=A1lez?= Oct. 2, 2017, 11:27 a.m. UTC
> 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?

Comments

Rakesh Pandit Oct. 2, 2017, 11:43 a.m. UTC | #1
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,
=?UTF-8?q?Javier=20Gonz=C3=A1lez?= Oct. 2, 2017, 11:44 a.m. UTC | #2
> On 2 Oct 2017, at 13.43, Rakesh Pandit <rakesh@tuxera.com> wrote:
> 
> 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.
> 

Cool. I'll fix it when picking it up.

Javier
diff mbox

Patch

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