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From: Thomas Monjalon <thomas@monjalon.net>
To: Suanming Mou <suanmingm@nvidia.com>,
	Stephen Hemminger <stephen@networkplumber.org>
Cc: Ori Kam <orika@mellanox.com>, Matan Azrad <matan@mellanox.com>,
	Shahaf Shuler <shahafs@mellanox.com>,
	Viacheslav Ovsiienko <viacheslavo@mellanox.com>,
	Ferruh Yigit <ferruh.yigit@intel.com>,
	Andrew Rybchenko <arybchenko@solarflare.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	joyce.kong@arm.com, phil.yang@arm.com, steve.capper@arm.com,
	honnappa.nagarahalli@arm.com
Subject: Re: [dpdk-dev] [RFC] ethdev: make rte flow API thread safe
Date: Tue, 08 Sep 2020 17:03:53 +0200	[thread overview]
Message-ID: <3402903.UWDKPdykxe@thomas> (raw)
In-Reply-To: <20200908075208.048bfa02@hermes.lan>

08/09/2020 16:52, Stephen Hemminger:
> On Mon, 7 Sep 2020 02:36:48 +0000
> Suanming Mou <suanmingm@nvidia.com> wrote:
> > > What is the performance impact of this for currently working applications that
> > > use a single thread to program flow rules.  You are adding a couple of system
> > > calls to what was formerly a totally usermode operation.  
> 
> Read the source for glibc and see what pthread_mutex does

What would be the best lock for rte_flow?
We have spin lock, ticket lock, MCS lock (and rwlock) in DPDK.


> > If I understand correctly, in the non-contended single thread case, pthread mutex lock should not go to the kernel space.
> > I also wrote a small application with pthread mutex, and strace shows no system call was introduced.
> > 
> > Another simple testing code below is to check the cycles cost difference in every round between pthread mutex and spin_lock.
> 
> Micro benchmarks of locking is hard to see.




  reply	other threads:[~2020-09-08 15:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-03  4:53 Suanming Mou
2020-09-03 17:37 ` Stephen Hemminger
2020-09-07  2:36   ` Suanming Mou
2020-09-08 14:52     ` Stephen Hemminger
2020-09-08 15:03       ` Thomas Monjalon [this message]
2020-09-08 16:02         ` Stephen Hemminger
2020-09-09  2:26           ` Suanming Mou
2020-09-24  1:42             ` Suanming Mou
2020-09-09  1:26       ` Suanming Mou

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