* [PATCH] mmc: core: optimize mmc_calc_max_discard
@ 2018-02-07 23:59 Sergio Valverde
2018-02-08 17:41 ` [PATCH v2] " Sergio Valverde
0 siblings, 1 reply; 4+ messages in thread
From: Sergio Valverde @ 2018-02-07 23:59 UTC (permalink / raw)
Cc: Sergio Valverde, Ulf Hansson, Linus Walleij, Shawn Lin,
Adrian Hunter, Bartlomiej Zolnierkiewicz, linux-mmc, linux-kernel
If the max_discard value is zero, the conditional branch that checks the
trim capabilities will never update this value with max_trim.
Change the condition statement to also check the max_discard value in order
to avoid an unnecessary call to mmc_do_calc_max_discard.
Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
---
drivers/mmc/core/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1f0f44f..97856b1 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2567,7 +2567,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
return card->pref_erase;
max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
- if (mmc_can_trim(card)) {
+ if (mmc_can_trim(card) && max_discard) {
max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
if (max_trim < max_discard)
max_discard = max_trim;
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2] mmc: core: optimize mmc_calc_max_discard
2018-02-07 23:59 [PATCH] mmc: core: optimize mmc_calc_max_discard Sergio Valverde
@ 2018-02-08 17:41 ` Sergio Valverde
2018-02-09 7:38 ` Shawn Lin
2018-02-14 10:38 ` Ulf Hansson
0 siblings, 2 replies; 4+ messages in thread
From: Sergio Valverde @ 2018-02-08 17:41 UTC (permalink / raw)
Cc: Sergio Valverde, Ulf Hansson, Linus Walleij, Shawn Lin,
Adrian Hunter, Bartlomiej Zolnierkiewicz, linux-mmc, linux-kernel
If the max_discard value is zero, the conditional branch that checks the
trim capabilities will never update this value with max_trim.
Change the condition statement to also check the max_discard value in order
to avoid an unnecessary call to mmc_do_calc_max_discard.
Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
---
Changes in v2:
- Evaluate max_discard to avoid unnecessary calls to mmc_can_trim.
drivers/mmc/core/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 1f0f44f..c32c0f4 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2567,7 +2567,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
return card->pref_erase;
max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
- if (mmc_can_trim(card)) {
+ if (max_discard && mmc_can_trim(card)) {
max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
if (max_trim < max_discard)
max_discard = max_trim;
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] mmc: core: optimize mmc_calc_max_discard
2018-02-08 17:41 ` [PATCH v2] " Sergio Valverde
@ 2018-02-09 7:38 ` Shawn Lin
2018-02-14 10:38 ` Ulf Hansson
1 sibling, 0 replies; 4+ messages in thread
From: Shawn Lin @ 2018-02-09 7:38 UTC (permalink / raw)
To: Sergio Valverde
Cc: shawn.lin, Ulf Hansson, Linus Walleij, Adrian Hunter,
Bartlomiej Zolnierkiewicz, linux-mmc
On 2018/2/9 1:41, Sergio Valverde wrote:
> If the max_discard value is zero, the conditional branch that checks the
> trim capabilities will never update this value with max_trim.
>
> Change the condition statement to also check the max_discard value in order
> to avoid an unnecessary call to mmc_do_calc_max_discard.
>
Given it's not in the hot call patch and it's rare to return zero from
mmc_do_calc_max_discard if you read the code instead of doing sanity
check by tools. So I doubt there is no gain in practice. But FWIW,
Reviewed-by: Shawn Lin <shawn.lin@rock-chip.com>
> Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
> ---
> Changes in v2:
> - Evaluate max_discard to avoid unnecessary calls to mmc_can_trim.
>
> drivers/mmc/core/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 1f0f44f..c32c0f4 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2567,7 +2567,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
> return card->pref_erase;
>
> max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
> - if (mmc_can_trim(card)) {
> + if (max_discard && mmc_can_trim(card)) {
> max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
> if (max_trim < max_discard)
> max_discard = max_trim;
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v2] mmc: core: optimize mmc_calc_max_discard
2018-02-08 17:41 ` [PATCH v2] " Sergio Valverde
2018-02-09 7:38 ` Shawn Lin
@ 2018-02-14 10:38 ` Ulf Hansson
1 sibling, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2018-02-14 10:38 UTC (permalink / raw)
To: Sergio Valverde
Cc: Linus Walleij, Shawn Lin, Adrian Hunter,
Bartlomiej Zolnierkiewicz, linux-mmc@vger.kernel.org,
Linux Kernel Mailing List
On 8 February 2018 at 18:41, Sergio Valverde <vlvrdv@gmail.com> wrote:
> If the max_discard value is zero, the conditional branch that checks the
> trim capabilities will never update this value with max_trim.
>
> Change the condition statement to also check the max_discard value in order
> to avoid an unnecessary call to mmc_do_calc_max_discard.
>
> Signed-off-by: Sergio Valverde <vlvrdv@gmail.com>
Thanks, applied for next!
Kind regards
Uffe
> ---
> Changes in v2:
> - Evaluate max_discard to avoid unnecessary calls to mmc_can_trim.
>
> drivers/mmc/core/core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 1f0f44f..c32c0f4 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2567,7 +2567,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
> return card->pref_erase;
>
> max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG);
> - if (mmc_can_trim(card)) {
> + if (max_discard && mmc_can_trim(card)) {
> max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG);
> if (max_trim < max_discard)
> max_discard = max_trim;
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-02-14 10:38 UTC | newest]
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2018-02-07 23:59 [PATCH] mmc: core: optimize mmc_calc_max_discard Sergio Valverde
2018-02-08 17:41 ` [PATCH v2] " Sergio Valverde
2018-02-09 7:38 ` Shawn Lin
2018-02-14 10:38 ` Ulf Hansson
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