Re: [PATCH net-next 1/5] net: napi: Make napi_defer_hard_irqs per-NAPI

[Joe Damato <jdamato@fastly.com>]

On Fri, Aug 30, 2024 at 09:36:41AM +0100, Simon Horman wrote:
> On Thu, Aug 29, 2024 at 01:11:57PM +0000, Joe Damato wrote:
> > Allow per-NAPI defer_hard_irqs setting.
> > 
> > The existing sysfs parameter is respected; writes to sysfs will write to
> > all NAPI structs for the device and the net_device defer_hard_irq field.
> > Reads from sysfs will read from the net_device field.
> > 
> > sysfs code was updated to guard against what appears to be a potential
> > overflow as the field is an int, but the value passed in is an unsigned
> > long.
> > 
> > The ability to set defer_hard_irqs on specific NAPI instances will be
> > added in a later commit, via netdev-genl.
> > 
> > Signed-off-by: Joe Damato <jdamato@fastly.com>
> > Reviewed-by: Martin Karsten <mkarsten@uwaterloo.ca>
> > Tested-by: Martin Karsten <mkarsten@uwaterloo.ca>
> > ---
> >  include/linux/netdevice.h | 23 +++++++++++++++++++++++
> >  net/core/dev.c            | 29 ++++++++++++++++++++++++++---
> >  net/core/net-sysfs.c      |  5 ++++-
> >  3 files changed, 53 insertions(+), 4 deletions(-)
> 
> ...
> 
> > @@ -534,6 +535,28 @@ static inline void napi_schedule_irqoff(struct napi_struct *n)
> >  		__napi_schedule_irqoff(n);
> >  }
> >  
> > +/**
> > + * napi_get_defer_hard_irqs - get the NAPI's defer_hard_irqs
> > + * @n: napi struct to get the defer_hard_irqs field from
> > + *
> > + * Returns the per-NAPI value of the defar_hard_irqs field.
> > + */
> > +int napi_get_defer_hard_irqs(const struct napi_struct *n);
> 
> Hi Joe,
> 
> As it looks like there will be a v2 anyway, a minor nit from my side.
> 
> Thanks for documenting the return value, but I believe that
> ./scripts/kernel-doc -none -Wall expects "Return: " or "Returns: "
> 
> Likewise in patch 3/5.

Thanks Simon, will make sure to take care of this in the v2.