> -----Original Message----- > From: Nithin Dabilpuram <ndabilpu...@marvell.com> > Sent: Wednesday, July 17, 2019 9:44 PM > To: Hyong Youb Kim (hyonkim) <hyon...@cisco.com>; David Marchand > <david.march...@redhat.com>; Thomas Monjalon > <tho...@monjalon.net>; Ferruh Yigit <ferruh.yi...@intel.com>; Bruce > Richardson <bruce.richard...@intel.com> > Cc: jer...@marvell.com; John Daley (johndale) <johnd...@cisco.com>; > Shahed Shaikh <shsha...@marvell.com>; dev@dpdk.org; Nithin Dabilpuram > <ndabilpu...@marvell.com> > Subject: [PATCH v2 2/3] eal: add ack interrupt API > > Add new ack interrupt API to avoid using > VFIO_IRQ_SET_ACTION_TRIGGER(rte_intr_enable()) for > acking interrupt purpose for VFIO based interrupt handlers. > This implementation is specific to Linux. > > Using rte_intr_enable() for acking interrupt has below issues > > * Time consuming to do for every interrupt received as it will > free_irq() followed by request_irq() and all other initializations > * A race condition because of a window between free_irq() and > request_irq() with packet reception still on and device still > enabled and would throw warning messages like below. > [158764.159833] do_IRQ: 9.34 No irq handler for vector > > In this patch, rte_intr_ack() is a no-op for VFIO_MSIX/VFIO_MSI interrupts > as they are edge triggered and kernel would not mask the interrupt before > delivering the event to userspace and we don't need to ack. > > Signed-off-by: Nithin Dabilpuram <ndabilpu...@marvell.com> > Signed-off-by: Jerin Jacob <jer...@marvell.com> > --- > v2: > * No change > > lib/librte_eal/common/include/rte_interrupts.h | 22 +++++++ > lib/librte_eal/freebsd/eal/eal_interrupts.c | 9 +++ > lib/librte_eal/linux/eal/eal_interrupts.c | 81 > ++++++++++++++++++++++++++ > lib/librte_eal/rte_eal_version.map | 1 + > 4 files changed, 113 insertions(+) > > diff --git a/lib/librte_eal/common/include/rte_interrupts.h > b/lib/librte_eal/common/include/rte_interrupts.h > index c1e912c..93b31cd 100644 > --- a/lib/librte_eal/common/include/rte_interrupts.h > +++ b/lib/librte_eal/common/include/rte_interrupts.h > @@ -118,6 +118,28 @@ int rte_intr_enable(const struct rte_intr_handle > *intr_handle); > */ > int rte_intr_disable(const struct rte_intr_handle *intr_handle); > > +/** > + * It acks an interrupt raised for the specified handle. > + * > + * Call this function to ack an interrupt from interrupt > + * handler either from application or driver, so that > + * new interrupts are raised. > + * > + * @note For interrupt handle types VFIO_MSIX and VFIO_MSI, > + * this function is a no-op and returns success without > + * changing anything as kernel doesn't expect > + * them to be acked. > + * [...]
Shouldn't we explain that this really is "unmask" but named "ack" because of x and y, and that it is expected at end of INTx handler? Ack does not have a well-defined meaning, whereas everyone knows what unmask means.. [...] Thanks. -Hyong
