> -----Original Message----- > From: Stephen Hemminger <step...@networkplumber.org> > Sent: Wednesday, July 7, 2021 10:48 PM > To: Ruifeng Wang <ruifeng.w...@arm.com> > Cc: dev@dpdk.org; david.march...@redhat.com; tho...@monjalon.net; > jer...@marvell.com; nd <n...@arm.com>; Honnappa Nagarahalli > <honnappa.nagaraha...@arm.com> > Subject: Re: [dpdk-dev] Use WFE for spinlock and ring > > On Sun, 25 Apr 2021 05:56:51 +0000 > Ruifeng Wang <ruifeng.w...@arm.com> wrote: > > > The rte_wait_until_equal_xxx APIs abstract the functionality of > > 'polling for a memory location to become equal to a given value'[1]. > > > > Use the API for the rte spinlock and ring implementations. > > With the wait until equal APIs being stable, changes will not impact ABI. > > > > [1] http://patches.dpdk.org/cover/62703/ > > > > v3: > > Series rebased. (David) > > > > Gavin Hu (1): > > spinlock: use wfe to reduce contention on aarch64 > > > > Ruifeng Wang (1): > > ring: use wfe to wait for ring tail update on aarch64 > > > > lib/eal/include/generic/rte_spinlock.h | 4 ++-- > > lib/ring/rte_ring_c11_pvt.h | 4 ++-- > > lib/ring/rte_ring_generic_pvt.h | 3 +-- > > 3 files changed, 5 insertions(+), 6 deletions(-) > > > > Other places that should use WFE: Thank you Stephen for looking into this.
> > rte_mcslock.h:rte_mcslock_lock() Existing API can be used in this one. > rte_mcslock_unlock:rte_mcslock_unlock() This one needs rte_wait_while_xxx variant. > > rte_pflock.h:rte_pflock_lock() > rte_rwlock.h:rte_rwlock_read_lock() > rte_rwlock.h:rte_rwlock_write_lock() These occurrences have extra logic (AND, conditional branch, CAS) in the loop. I'm not sure generic API can be abstracted from these use cases. > > > You should also introduce rte_wait_while_XXX variants to handle some of > these cases. >
