Hi, OK. Thanks very much for detailed explanation. BR Yan Limin
-----Original Message----- From: Savolainen, Petri (Nokia - FI/Espoo) Sent: Wednesday, September 05, 2018 3:29 PM To: Yan, Liming (NSB - CN/Hangzhou) <liming....@nokia-sbell.com>; Bill Fischofer <bill.fischo...@linaro.org> Cc: lng-odp-forward <lng-odp@lists.linaro.org> Subject: RE: [lng-odp] Are those Asynchronous ordered locks available for use in 1.19? Hi, These calls have been implemented by the API spec. So, you can use those in your application. Lock_start() hints implementation that a lock_wait() will follow, but implementation is free to ignore the hint (if there's nothing it can do as preparation for lock_wait()). Lock_wait() is the one that must ensure synchronization. Odp-linux or odp-dpdk implementations ignore lock_start() and do normal lock call in lock_wait(), as the (current) SW implementation is synchronous. May be we could e.g. do a memory prefetch at lock_start(), but not much more. However, ODP implementations with a HW scheduler may very well use this hint for their benefit and your application could run there faster when using lock_start() and lock_wait(), instead of the normal _lock(). For example, Cavium implementations may benefit from these calls, as these were added from their request. -Petri > -----Original Message----- > From: lng-odp <lng-odp-boun...@lists.linaro.org> On Behalf Of Yan, > Liming (NSB - CN/Hangzhou) > Sent: Wednesday, September 5, 2018 6:15 AM > To: Bill Fischofer <bill.fischo...@linaro.org> > Cc: lng-odp-forward <lng-odp@lists.linaro.org> > Subject: Re: [lng-odp] Are those Asynchronous ordered locks available > for use in 1.19? > > Hi, > Thanks. You mean aync ordering lock needs HW support? I’m using > odp- dpdk in virtual machine. So can I use > odp_schedule_order_lock_start() and > odp_schedule_order_lock_wait() for async ordering lock? > > > BR > Yan Limin > > From: Bill Fischofer [mailto:bill.fischo...@linaro.org] > Sent: Tuesday, September 04, 2018 7:45 PM > To: Yan, Liming (NSB - CN/Hangzhou) <liming....@nokia-sbell.com> > Cc: lng-odp-forward <lng-odp@lists.linaro.org> > Subject: Re: [lng-odp] Are those Asynchronous ordered locks available > for use in 1.19? > > Yes, these APIs are available however only platforms with HW support > will show a practical difference in behavior. These APIs are hints to > the implementation, which is why you cannot assume you hold the lock > until after odp_schedule_order_lock_wait() completes. > > On Tue, Sep 4, 2018 at 6:41 AM Yan, Liming (NSB - CN/Hangzhou) > <liming....@nokia-sbell.com<mailto:liming....@nokia-sbell.com>> wrote: > Hi, > I see in change log: > > Asynchronous ordered locks > Two new APIs, odp_schedule_order_lock_start() and > odp_schedule_order_lock_wait() are added to allow for asynchronous > ordered lock acquisition in addition to the existing synchronous > odp_schedule_order_lock() API. In some implementations and > applications, there may be a performance advantage to indicating the > intent to acquire an ordered lock to allow the implementation to > prepare for this while the application continues parallel processing > and then enter the critical section protected by the ordered lock at a > later time. In this case ordered lock protection is not guaranteed > until the odp_schedule_order_lock_wait() call returns. > > But when I check the APIs code, seems they're still synchronous > calling, similar with schedule_order_lock. Maybe I don't get how to > use these APIs. I didn't see any examples. So my question is, Are > those Asynchronous ordered locks available for use? And how to use them? > Thanks very much. > > static void schedule_order_lock_wait(uint32_t lock_index) { > schedule_order_lock(lock_index); } > > > > BR > Yan Limin >
