| Message ID | 20231003145150.2498-4-ansuelsmth@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [net-next,v2,1/4] netdev: replace simple napi_schedule_prep/__napi_schedule to napi_schedule | expand |
On Fri, Oct 6, 2023 at 8:49 PM Christian Marangi <ansuelsmth@gmail.com> 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 <ansuelsmth@gmail.com> wrote: > > > > > > Replace if condition of napi_schedule_prep/__napi_schedule and use bool > > > from napi_schedule directly where possible. > > > > > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> > > > --- > > > 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.
On Sun, Oct 08, 2023 at 09:08:41AM +0200, Eric Dumazet wrote: > On Fri, Oct 6, 2023 at 8:49 PM Christian Marangi <ansuelsmth@gmail.com> 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 <ansuelsmth@gmail.com> wrote: > > > > > > > > Replace if condition of napi_schedule_prep/__napi_schedule and use bool > > > > from napi_schedule directly where possible. > > > > > > > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> > > > > --- > > > > 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!
On Sun, Oct 8, 2023 at 8:27 PM Christian Marangi <ansuelsmth@gmail.com> 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 <ansuelsmth@gmail.com> 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 <ansuelsmth@gmail.com> wrote: > > > > > > > > > > Replace if condition of napi_schedule_prep/__napi_schedule and use bool > > > > > from napi_schedule directly where possible. > > > > > > > > > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> > > > > > --- > > > > > 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...
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();
Replace if condition of napi_schedule_prep/__napi_schedule and use bool from napi_schedule directly where possible. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> --- 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(-)