Replace if condition of napi_schedule_prep/__napi_schedule and use bool
from napi_schedule directly where possible.
Signed-off-by: Christian Marangi <[email protected]>
---
drivers/net/ethernet/atheros/atlx/atl1.c | 4 +---
drivers/net/ethernet/toshiba/tc35815.c | 4 +---
drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 4 +---
3 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
index 02aa6fd8ebc2..a9014d7932db 100644
--- a/drivers/net/ethernet/atheros/atlx/atl1.c
+++ b/drivers/net/ethernet/atheros/atlx/atl1.c
@@ -2446,7 +2446,7 @@ static int atl1_rings_clean(struct napi_struct *napi, int budget)
static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
{
- if (!napi_schedule_prep(&adapter->napi))
+ if (!napi_schedule(&adapter->napi))
/* It is possible in case even the RX/TX ints are disabled via IMR
* register the ISR bits are set anyway (but do not produce IRQ).
* To handle such situation the napi functions used to check is
@@ -2454,8 +2454,6 @@ static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
*/
return 0;
- __napi_schedule(&adapter->napi);
-
/*
* Disable RX/TX ints via IMR register if it is
* allowed. NAPI handler must reenable them in same
diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
index 14cf6ecf6d0d..a8b8a0e13f9a 100644
--- a/drivers/net/ethernet/toshiba/tc35815.c
+++ b/drivers/net/ethernet/toshiba/tc35815.c
@@ -1436,9 +1436,7 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
if (!(dmactl & DMA_IntMask)) {
/* disable interrupts */
tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
- if (napi_schedule_prep(&lp->napi))
- __napi_schedule(&lp->napi);
- else {
+ if (!napi_schedule(&lp->napi)) {
printk(KERN_ERR "%s: interrupt taken in poll\n",
dev->name);
BUG();
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
index 23b5a0adcbd6..146bc7bd14fb 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
@@ -1660,9 +1660,7 @@ irqreturn_t iwl_pcie_irq_rx_msix_handler(int irq, void *dev_id)
IWL_DEBUG_ISR(trans, "[%d] Got interrupt\n", entry->entry);
local_bh_disable();
- if (napi_schedule_prep(&rxq->napi))
- __napi_schedule(&rxq->napi);
- else
+ if (!napi_schedule(&rxq->napi))
iwl_pcie_clear_irq(trans, entry->entry);
local_bh_enable();
--
2.40.1
On Tue, Oct 3, 2023 at 8:36 PM Christian Marangi <[email protected]> wrote:
>
> Replace if condition of napi_schedule_prep/__napi_schedule and use bool
> from napi_schedule directly where possible.
>
> Signed-off-by: Christian Marangi <[email protected]>
> ---
> drivers/net/ethernet/atheros/atlx/atl1.c | 4 +---
> drivers/net/ethernet/toshiba/tc35815.c | 4 +---
> drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 4 +---
> 3 files changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
> index 02aa6fd8ebc2..a9014d7932db 100644
> --- a/drivers/net/ethernet/atheros/atlx/atl1.c
> +++ b/drivers/net/ethernet/atheros/atlx/atl1.c
> @@ -2446,7 +2446,7 @@ static int atl1_rings_clean(struct napi_struct *napi, int budget)
>
> static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> {
> - if (!napi_schedule_prep(&adapter->napi))
> + if (!napi_schedule(&adapter->napi))
> /* It is possible in case even the RX/TX ints are disabled via IMR
> * register the ISR bits are set anyway (but do not produce IRQ).
> * To handle such situation the napi functions used to check is
> @@ -2454,8 +2454,6 @@ static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> */
> return 0;
>
> - __napi_schedule(&adapter->napi);
> -
> /*
> * Disable RX/TX ints via IMR register if it is
> * allowed. NAPI handler must reenable them in same
> diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
> index 14cf6ecf6d0d..a8b8a0e13f9a 100644
> --- a/drivers/net/ethernet/toshiba/tc35815.c
> +++ b/drivers/net/ethernet/toshiba/tc35815.c
> @@ -1436,9 +1436,7 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
> if (!(dmactl & DMA_IntMask)) {
> /* disable interrupts */
> tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> - if (napi_schedule_prep(&lp->napi))
> - __napi_schedule(&lp->napi);
> - else {
> + if (!napi_schedule(&lp->napi)) {
> printk(KERN_ERR "%s: interrupt taken in poll\n",
> dev->name);
> BUG();
Hmmm... could you also remove this BUG() ? I think this code path can be taken
if some applications are using busy polling.
Or simply rewrite this with the traditional
if (napi_schedule_prep(&lp->napi)) {
/* disable interrupts */
tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
__napi_schedule(&lp->napi);
}
> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> index 23b5a0adcbd6..146bc7bd14fb 100644
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> @@ -1660,9 +1660,7 @@ irqreturn_t iwl_pcie_irq_rx_msix_handler(int irq, void *dev_id)
> IWL_DEBUG_ISR(trans, "[%d] Got interrupt\n", entry->entry);
>
> local_bh_disable();
> - if (napi_schedule_prep(&rxq->napi))
> - __napi_schedule(&rxq->napi);
> - else
> + if (!napi_schedule(&rxq->napi))
> iwl_pcie_clear_irq(trans, entry->entry);
Same remark here about twisted logic.
> local_bh_enable();
>
> --
> 2.40.1
>
On Thu, Oct 05, 2023 at 06:16:26PM +0200, Eric Dumazet wrote:
> On Tue, Oct 3, 2023 at 8:36 PM Christian Marangi <[email protected]> wrote:
> >
> > Replace if condition of napi_schedule_prep/__napi_schedule and use bool
> > from napi_schedule directly where possible.
> >
> > Signed-off-by: Christian Marangi <[email protected]>
> > ---
> > drivers/net/ethernet/atheros/atlx/atl1.c | 4 +---
> > drivers/net/ethernet/toshiba/tc35815.c | 4 +---
> > drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 4 +---
> > 3 files changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
> > index 02aa6fd8ebc2..a9014d7932db 100644
> > --- a/drivers/net/ethernet/atheros/atlx/atl1.c
> > +++ b/drivers/net/ethernet/atheros/atlx/atl1.c
> > @@ -2446,7 +2446,7 @@ static int atl1_rings_clean(struct napi_struct *napi, int budget)
> >
> > static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > {
> > - if (!napi_schedule_prep(&adapter->napi))
> > + if (!napi_schedule(&adapter->napi))
> > /* It is possible in case even the RX/TX ints are disabled via IMR
> > * register the ISR bits are set anyway (but do not produce IRQ).
> > * To handle such situation the napi functions used to check is
> > @@ -2454,8 +2454,6 @@ static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > */
> > return 0;
> >
> > - __napi_schedule(&adapter->napi);
> > -
> > /*
> > * Disable RX/TX ints via IMR register if it is
> > * allowed. NAPI handler must reenable them in same
> > diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
> > index 14cf6ecf6d0d..a8b8a0e13f9a 100644
> > --- a/drivers/net/ethernet/toshiba/tc35815.c
> > +++ b/drivers/net/ethernet/toshiba/tc35815.c
> > @@ -1436,9 +1436,7 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
> > if (!(dmactl & DMA_IntMask)) {
> > /* disable interrupts */
> > tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> > - if (napi_schedule_prep(&lp->napi))
> > - __napi_schedule(&lp->napi);
> > - else {
> > + if (!napi_schedule(&lp->napi)) {
> > printk(KERN_ERR "%s: interrupt taken in poll\n",
> > dev->name);
> > BUG();
>
> Hmmm... could you also remove this BUG() ? I think this code path can be taken
> if some applications are using busy polling.
>
> Or simply rewrite this with the traditional
>
> if (napi_schedule_prep(&lp->napi)) {
> /* disable interrupts */
> tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> __napi_schedule(&lp->napi);
> }
>
>
Mhhh is it safe to do so? I mean it seems very wrong to print a warning
and BUG() instead of disabling the interrupt only if napi can be
scheduled... Maybe is very old code? The more I see this the more I see
problem... (randomly disabling the interrupt and then make the kernel
die)
>
> > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> > index 23b5a0adcbd6..146bc7bd14fb 100644
> > --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> > +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c
> > @@ -1660,9 +1660,7 @@ irqreturn_t iwl_pcie_irq_rx_msix_handler(int irq, void *dev_id)
> > IWL_DEBUG_ISR(trans, "[%d] Got interrupt\n", entry->entry);
> >
> > local_bh_disable();
> > - if (napi_schedule_prep(&rxq->napi))
> > - __napi_schedule(&rxq->napi);
> > - else
> > + if (!napi_schedule(&rxq->napi))
> > iwl_pcie_clear_irq(trans, entry->entry);
>
> Same remark here about twisted logic.
>
Ehhh here we need to be careful... We can do the usual prep/__schedule
with the DMA disable in between...
From the comments of iwl_pcie_clear_irq.
/*
* Before sending the interrupt the HW disables it to prevent
* a nested interrupt. This is done by writing 1 to the corresponding
* bit in the mask register. After handling the interrupt, it should be
* re-enabled by clearing this bit. This register is defined as
* write 1 clear (W1C) register, meaning that it's being clear
* by writing 1 to the bit.
*/
So the device disable the interrupt after being fired and the bit needs
to set again for the interrupt to be reenabled. So the function
correctly reenable the irq if a napi can't be scheduled... Think there
isn't another way to handle this.
> > local_bh_enable();
> >
> > --
> > 2.40.1
> >
--
Ansuel
On Sun, Oct 08, 2023 at 09:08:41AM +0200, Eric Dumazet wrote:
> On Fri, Oct 6, 2023 at 8:49 PM Christian Marangi <[email protected]> wrote:
> >
> > On Thu, Oct 05, 2023 at 06:16:26PM +0200, Eric Dumazet wrote:
> > > On Tue, Oct 3, 2023 at 8:36 PM Christian Marangi <[email protected]> wrote:
> > > >
> > > > Replace if condition of napi_schedule_prep/__napi_schedule and use bool
> > > > from napi_schedule directly where possible.
> > > >
> > > > Signed-off-by: Christian Marangi <[email protected]>
> > > > ---
> > > > drivers/net/ethernet/atheros/atlx/atl1.c | 4 +---
> > > > drivers/net/ethernet/toshiba/tc35815.c | 4 +---
> > > > drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 4 +---
> > > > 3 files changed, 3 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > index 02aa6fd8ebc2..a9014d7932db 100644
> > > > --- a/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > +++ b/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > @@ -2446,7 +2446,7 @@ static int atl1_rings_clean(struct napi_struct *napi, int budget)
> > > >
> > > > static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > > > {
> > > > - if (!napi_schedule_prep(&adapter->napi))
> > > > + if (!napi_schedule(&adapter->napi))
> > > > /* It is possible in case even the RX/TX ints are disabled via IMR
> > > > * register the ISR bits are set anyway (but do not produce IRQ).
> > > > * To handle such situation the napi functions used to check is
> > > > @@ -2454,8 +2454,6 @@ static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > > > */
> > > > return 0;
> > > >
> > > > - __napi_schedule(&adapter->napi);
> > > > -
> > > > /*
> > > > * Disable RX/TX ints via IMR register if it is
> > > > * allowed. NAPI handler must reenable them in same
> > > > diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
> > > > index 14cf6ecf6d0d..a8b8a0e13f9a 100644
> > > > --- a/drivers/net/ethernet/toshiba/tc35815.c
> > > > +++ b/drivers/net/ethernet/toshiba/tc35815.c
> > > > @@ -1436,9 +1436,7 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
> > > > if (!(dmactl & DMA_IntMask)) {
> > > > /* disable interrupts */
> > > > tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> > > > - if (napi_schedule_prep(&lp->napi))
> > > > - __napi_schedule(&lp->napi);
> > > > - else {
> > > > + if (!napi_schedule(&lp->napi)) {
> > > > printk(KERN_ERR "%s: interrupt taken in poll\n",
> > > > dev->name);
> > > > BUG();
> > >
> > > Hmmm... could you also remove this BUG() ? I think this code path can be taken
> > > if some applications are using busy polling.
> > >
> > > Or simply rewrite this with the traditional
> > >
> > > if (napi_schedule_prep(&lp->napi)) {
> > > /* disable interrupts */
> > > tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> > > __napi_schedule(&lp->napi);
> > > }
> > >
> > >
> >
> > Mhhh is it safe to do so? I mean it seems very wrong to print a warning
> > and BUG() instead of disabling the interrupt only if napi can be
> > scheduled... Maybe is very old code? The more I see this the more I see
> > problem... (randomly disabling the interrupt and then make the kernel
> > die)
>
> I am pretty sure this BUG() can be hit these days with busy polling or
> setting gro_flush_timeout.
>
> I wish we could remove these bugs before someone copy-paste them.
>
> Again, this is orthogonal, I might simply stop doing reviews if this
> is not useful.
They are very useful and thanks a lot for them! I'm asking these as to
understand how to proceed. I have in queue 2 other series that depends
on this and I'm just asking info on how to speedup the progress on this!
Soo think I have to send v3 with the suggested change and BUG() dropped?
Happy to do everything to fix and improve this series!
--
Ansuel
On Sun, Oct 8, 2023 at 8:27 PM Christian Marangi <[email protected]> wrote:
>
> On Sun, Oct 08, 2023 at 09:08:41AM +0200, Eric Dumazet wrote:
> > On Fri, Oct 6, 2023 at 8:49 PM Christian Marangi <[email protected]> wrote:
> > >
> > > On Thu, Oct 05, 2023 at 06:16:26PM +0200, Eric Dumazet wrote:
> > > > On Tue, Oct 3, 2023 at 8:36 PM Christian Marangi <[email protected]> wrote:
> > > > >
> > > > > Replace if condition of napi_schedule_prep/__napi_schedule and use bool
> > > > > from napi_schedule directly where possible.
> > > > >
> > > > > Signed-off-by: Christian Marangi <[email protected]>
> > > > > ---
> > > > > drivers/net/ethernet/atheros/atlx/atl1.c | 4 +---
> > > > > drivers/net/ethernet/toshiba/tc35815.c | 4 +---
> > > > > drivers/net/wireless/intel/iwlwifi/pcie/rx.c | 4 +---
> > > > > 3 files changed, 3 insertions(+), 9 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > > index 02aa6fd8ebc2..a9014d7932db 100644
> > > > > --- a/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > > +++ b/drivers/net/ethernet/atheros/atlx/atl1.c
> > > > > @@ -2446,7 +2446,7 @@ static int atl1_rings_clean(struct napi_struct *napi, int budget)
> > > > >
> > > > > static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > > > > {
> > > > > - if (!napi_schedule_prep(&adapter->napi))
> > > > > + if (!napi_schedule(&adapter->napi))
> > > > > /* It is possible in case even the RX/TX ints are disabled via IMR
> > > > > * register the ISR bits are set anyway (but do not produce IRQ).
> > > > > * To handle such situation the napi functions used to check is
> > > > > @@ -2454,8 +2454,6 @@ static inline int atl1_sched_rings_clean(struct atl1_adapter* adapter)
> > > > > */
> > > > > return 0;
> > > > >
> > > > > - __napi_schedule(&adapter->napi);
> > > > > -
> > > > > /*
> > > > > * Disable RX/TX ints via IMR register if it is
> > > > > * allowed. NAPI handler must reenable them in same
> > > > > diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
> > > > > index 14cf6ecf6d0d..a8b8a0e13f9a 100644
> > > > > --- a/drivers/net/ethernet/toshiba/tc35815.c
> > > > > +++ b/drivers/net/ethernet/toshiba/tc35815.c
> > > > > @@ -1436,9 +1436,7 @@ static irqreturn_t tc35815_interrupt(int irq, void *dev_id)
> > > > > if (!(dmactl & DMA_IntMask)) {
> > > > > /* disable interrupts */
> > > > > tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> > > > > - if (napi_schedule_prep(&lp->napi))
> > > > > - __napi_schedule(&lp->napi);
> > > > > - else {
> > > > > + if (!napi_schedule(&lp->napi)) {
> > > > > printk(KERN_ERR "%s: interrupt taken in poll\n",
> > > > > dev->name);
> > > > > BUG();
> > > >
> > > > Hmmm... could you also remove this BUG() ? I think this code path can be taken
> > > > if some applications are using busy polling.
> > > >
> > > > Or simply rewrite this with the traditional
> > > >
> > > > if (napi_schedule_prep(&lp->napi)) {
> > > > /* disable interrupts */
> > > > tc_writel(dmactl | DMA_IntMask, &tr->DMA_Ctl);
> > > > __napi_schedule(&lp->napi);
> > > > }
> > > >
> > > >
> > >
> > > Mhhh is it safe to do so? I mean it seems very wrong to print a warning
> > > and BUG() instead of disabling the interrupt only if napi can be
> > > scheduled... Maybe is very old code? The more I see this the more I see
> > > problem... (randomly disabling the interrupt and then make the kernel
> > > die)
> >
> > I am pretty sure this BUG() can be hit these days with busy polling or
> > setting gro_flush_timeout.
> >
> > I wish we could remove these bugs before someone copy-paste them.
> >
> > Again, this is orthogonal, I might simply stop doing reviews if this
> > is not useful.
>
> They are very useful and thanks a lot for them! I'm asking these as to
> understand how to proceed. I have in queue 2 other series that depends
> on this and I'm just asking info on how to speedup the progress on this!
>
> Soo think I have to send v3 with the suggested change and BUG() dropped?
> Happy to do everything to fix and improve this series!
I think that your patch series is all about doing cleanups,
so I suggested adding another cleanup/fix,
and this can be done independently.
I doubt this matters, this code has probably not been used for quite a
long time...