> -----Original Message----- > From: Liang, Cunming > Sent: Thursday, February 12, 2015 1:05 PM > To: Olivier MATZ; dev at dpdk.org > Cc: Ananyev, Konstantin > Subject: RE: [PATCH v5 18/19] ring: add sched_yield to avoid spin forever > > Hi, > > > -----Original Message----- > > From: Olivier MATZ [mailto:olivier.matz at 6wind.com] > > Sent: Thursday, February 12, 2015 7:16 PM > > To: Liang, Cunming; dev at dpdk.org > > Cc: Ananyev, Konstantin > > Subject: Re: [PATCH v5 18/19] ring: add sched_yield to avoid spin forever > > > > Hi, > > > > On 02/12/2015 09:16 AM, Cunming Liang wrote: > > > Add a sched_yield() syscall if the thread spins for too long, waiting > > > other thread > > to finish its operations on the ring. > > > That gives pre-empted thread a chance to proceed and finish with ring > > enqnue/dequeue operation. > > > The purpose is to reduce contention on the ring. By ring_perf_test, it > > > doesn't > > shows additional perf penalty. > > > > > > Signed-off-by: Cunming Liang <cunming.liang at intel.com> > > > --- > > > v5 changes: > > > add RTE_RING_PAUSE_REP to config file > > > > > > v4 changes: > > > update and add more comments on sched_yield() > > > > > > v3 changes: > > > new patch adding sched_yield() in rte_ring to avoid long spin > > > > > > config/common_bsdapp | 1 + > > > config/common_linuxapp | 1 + > > > lib/librte_ring/rte_ring.h | 31 +++++++++++++++++++++++++++---- > > > 3 files changed, 29 insertions(+), 4 deletions(-) > > > > > > diff --git a/config/common_bsdapp b/config/common_bsdapp > > > index 57bacb8..52c5143 100644 > > > --- a/config/common_bsdapp > > > +++ b/config/common_bsdapp > > > @@ -234,6 +234,7 @@ CONFIG_RTE_PMD_PACKET_PREFETCH=y > > > CONFIG_RTE_LIBRTE_RING=y > > > CONFIG_RTE_LIBRTE_RING_DEBUG=n > > > CONFIG_RTE_RING_SPLIT_PROD_CONS=n > > > +CONFIG_RTE_RING_PAUSE_REP=n > > > > Maybe it's better to use CONFIG_RTE_RING_PAUSE_REP=0 instead? > > If I understand well, it has to be set to an integer value to > > enable it, am I correct? > [LCM] If RTE_RING_PAUSE_REP=N (no define), by default will use 0. If it's set > to 'y'(=1), will issue yield in the most frequent rate. > It also can set as integer to assign any number. All cases works for this > configure. > One point is in configure file, just demonstrate the default way to use it. > It can't prevent to use anything unexpected. Except we rule the n & y illegal > for this option. > The meaningful value of it can write in the doc.
I also think that it is better avoid 'y' and 'n' (though as you said it would work), but use integers for all cases. Less confusion for the users. Konstantin > > > > Thanks, > > Olivier
