2018-03-19 06:30:09

by Daniel Mack

[permalink] [raw]
Subject: [PATCH] wcn36xx: allocate skbs with GFP_KERNEL during init

GFP_ATOMIC should only be used when the allocation is done from atomic
context. Introduce a new flag to wcn36xx_dxe_fill_skb() and use GFP_KERNEL
when pre-allocating buffers during init.

This doesn't fix an issue that was observed in the wild, but it reduces
the chance of failed allocations under memory pressure.

Signed-off-by: Daniel Mack <[email protected]>
---
drivers/net/wireless/ath/wcn36xx/dxe.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/ath/wcn36xx/dxe.c
index 5672154948c3..3e180828fbfa 100644
--- a/drivers/net/wireless/ath/wcn36xx/dxe.c
+++ b/drivers/net/wireless/ath/wcn36xx/dxe.c
@@ -275,12 +275,14 @@ static int wcn36xx_dxe_enable_ch_int(struct wcn36xx *wcn, u16 wcn_ch)
return 0;
}

-static int wcn36xx_dxe_fill_skb(struct device *dev, struct wcn36xx_dxe_ctl *ctl)
+static int wcn36xx_dxe_fill_skb(struct device *dev,
+ struct wcn36xx_dxe_ctl *ctl,
+ gfp_t gfp)
{
struct wcn36xx_dxe_desc *dxe = ctl->desc;
struct sk_buff *skb;

- skb = alloc_skb(WCN36XX_PKT_SIZE, GFP_ATOMIC);
+ skb = alloc_skb(WCN36XX_PKT_SIZE, gfp);
if (skb == NULL)
return -ENOMEM;

@@ -307,7 +309,7 @@ static int wcn36xx_dxe_ch_alloc_skb(struct wcn36xx *wcn,
cur_ctl = wcn_ch->head_blk_ctl;

for (i = 0; i < wcn_ch->desc_num; i++) {
- wcn36xx_dxe_fill_skb(wcn->dev, cur_ctl);
+ wcn36xx_dxe_fill_skb(wcn->dev, cur_ctl, GFP_KERNEL);
cur_ctl = cur_ctl->next;
}

@@ -533,7 +535,7 @@ static int wcn36xx_rx_handle_packets(struct wcn36xx *wcn,
while (!(dxe->ctrl & WCN36XX_DXE_CTRL_VALID_MASK)) {
skb = ctl->skb;
dma_addr = dxe->dst_addr_l;
- ret = wcn36xx_dxe_fill_skb(wcn->dev, ctl);
+ ret = wcn36xx_dxe_fill_skb(wcn->dev, ctl, GFP_ATOMIC);
if (0 == ret) {
/* new skb allocation ok. Use the new one and queue
* the old one to network system.
--
2.14.3


2018-03-29 18:04:12

by Daniel Mack

[permalink] [raw]
Subject: Re: [PATCH] wcn36xx: allocate skbs with GFP_KERNEL during init

On Monday, March 19, 2018 07:30 AM, Daniel Mack wrote:
> GFP_ATOMIC should only be used when the allocation is done from atomic
> context. Introduce a new flag to wcn36xx_dxe_fill_skb() and use GFP_KERNEL
> when pre-allocating buffers during init.
>
> This doesn't fix an issue that was observed in the wild, but it reduces
> the chance of failed allocations under memory pressure.
>
> Signed-off-by: Daniel Mack <[email protected]>

Any opinion about this one?


Thanks,
Daniel

> ---
> drivers/net/wireless/ath/wcn36xx/dxe.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/ath/wcn36xx/dxe.c
> index 5672154948c3..3e180828fbfa 100644
> --- a/drivers/net/wireless/ath/wcn36xx/dxe.c
> +++ b/drivers/net/wireless/ath/wcn36xx/dxe.c
> @@ -275,12 +275,14 @@ static int wcn36xx_dxe_enable_ch_int(struct wcn36xx *wcn, u16 wcn_ch)
> return 0;
> }
>
> -static int wcn36xx_dxe_fill_skb(struct device *dev, struct wcn36xx_dxe_ctl *ctl)
> +static int wcn36xx_dxe_fill_skb(struct device *dev,
> + struct wcn36xx_dxe_ctl *ctl,
> + gfp_t gfp)
> {
> struct wcn36xx_dxe_desc *dxe = ctl->desc;
> struct sk_buff *skb;
>
> - skb = alloc_skb(WCN36XX_PKT_SIZE, GFP_ATOMIC);
> + skb = alloc_skb(WCN36XX_PKT_SIZE, gfp);
> if (skb == NULL)
> return -ENOMEM;
>
> @@ -307,7 +309,7 @@ static int wcn36xx_dxe_ch_alloc_skb(struct wcn36xx *wcn,
> cur_ctl = wcn_ch->head_blk_ctl;
>
> for (i = 0; i < wcn_ch->desc_num; i++) {
> - wcn36xx_dxe_fill_skb(wcn->dev, cur_ctl);
> + wcn36xx_dxe_fill_skb(wcn->dev, cur_ctl, GFP_KERNEL);
> cur_ctl = cur_ctl->next;
> }
>
> @@ -533,7 +535,7 @@ static int wcn36xx_rx_handle_packets(struct wcn36xx *wcn,
> while (!(dxe->ctrl & WCN36XX_DXE_CTRL_VALID_MASK)) {
> skb = ctl->skb;
> dma_addr = dxe->dst_addr_l;
> - ret = wcn36xx_dxe_fill_skb(wcn->dev, ctl);
> + ret = wcn36xx_dxe_fill_skb(wcn->dev, ctl, GFP_ATOMIC);
> if (0 == ret) {
> /* new skb allocation ok. Use the new one and queue
> * the old one to network system.
>

2018-04-10 15:00:02

by Kalle Valo

[permalink] [raw]
Subject: Re: wcn36xx: allocate skbs with GFP_KERNEL during init

Daniel Mack <[email protected]> wrote:

> GFP_ATOMIC should only be used when the allocation is done from atomic
> context. Introduce a new flag to wcn36xx_dxe_fill_skb() and use GFP_KERNEL
> when pre-allocating buffers during init.
>
> This doesn't fix an issue that was observed in the wild, but it reduces
> the chance of failed allocations under memory pressure.
>
> Signed-off-by: Daniel Mack <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

5151a673da43 wcn36xx: allocate skbs with GFP_KERNEL during init

--
https://patchwork.kernel.org/patch/10291685/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2018-04-03 09:58:40

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH] wcn36xx: allocate skbs with GFP_KERNEL during init

Daniel Mack <[email protected]> writes:

> On Monday, March 19, 2018 07:30 AM, Daniel Mack wrote:
>> GFP_ATOMIC should only be used when the allocation is done from atomic
>> context. Introduce a new flag to wcn36xx_dxe_fill_skb() and use GFP_KERNEL
>> when pre-allocating buffers during init.
>>
>> This doesn't fix an issue that was observed in the wild, but it reduces
>> the chance of failed allocations under memory pressure.
>>
>> Signed-off-by: Daniel Mack <[email protected]>
>
> Any opinion about this one?

It's better that you check the state from patchwork, less mail to the
maintainers:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#checking_state_of_patches_from_patchwork

--
Kalle Valo