From: Stephen Hemminger <stephen@networkplumber.org>
To: "Eads, Gage" <gage.eads@intel.com>
Cc: "Burakov, Anatoly" <anatoly.burakov@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"olivier.matz@6wind.com" <olivier.matz@6wind.com>,
"arybchenko@solarflare.com" <arybchenko@solarflare.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>,
"Ananyev, Konstantin" <konstantin.ananyev@intel.com>
Subject: Re: [dpdk-dev] [PATCH 1/6] ring: change head and tail to pointer-width size
Date: Fri, 11 Jan 2019 11:55:15 -0800 [thread overview]
Message-ID: <20190111115515.524273ae@hermes.lan> (raw)
In-Reply-To: <9184057F7FC11744A2107296B6B8EB1E541C4C3E@FMSMSX108.amr.corp.intel.com>
On Fri, 11 Jan 2019 19:12:40 +0000
"Eads, Gage" <gage.eads@intel.com> wrote:
> > -----Original Message-----
> > From: Burakov, Anatoly
> > Sent: Friday, January 11, 2019 4:25 AM
> > To: Eads, Gage <gage.eads@intel.com>; dev@dpdk.org
> > Cc: olivier.matz@6wind.com; arybchenko@solarflare.com; Richardson, Bruce
> > <bruce.richardson@intel.com>; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>
> > Subject: Re: [dpdk-dev] [PATCH 1/6] ring: change head and tail to pointer-width
> > size
> >
> > On 10-Jan-19 9:01 PM, Gage Eads wrote:
> > > For 64-bit architectures, doubling the head and tail index widths
> > > greatly increases the time it takes for them to wrap-around (with
> > > current CPU speeds, it won't happen within the author's lifetime).
> > > This is important in avoiding the ABA problem -- in which a thread
> > > mistakes reading the same tail index in two accesses to mean that the
> > > ring was not modified in the intervening time -- in the upcoming
> > > non-blocking ring implementation. Using a 64-bit index makes the possibility of
> > this occurring effectively zero.
> > >
> > > I tested this commit's performance impact with an x86_64 build on a
> > > dual-socket Xeon E5-2699 v4 using ring_perf_autotest, and the change
> > > made no significant difference -- the few differences appear to be system
> > noise.
> > > (The test ran on isolcpus cores using a tickless scheduler, but some
> > > variation was stll observed.) Each test was run three times and the
> > > results were averaged:
> > >
> > > | 64b head/tail cycle cost minus
> > > Test | 32b head/tail cycle cost
> > > ------------------------------------------------------------------
> > > SP/SC single enq/dequeue | 0.33
> > > MP/MC single enq/dequeue | 0.00
> > > SP/SC burst enq/dequeue (size 8) | 0.00 MP/MC burst enq/dequeue (size
> > > 8) | 1.00 SP/SC burst enq/dequeue (size 32) | 0.00 MP/MC burst
> > > enq/dequeue (size 32) | -1.00
> > > SC empty dequeue | 0.01
> > > MC empty dequeue | 0.00
> > >
> > > Single lcore:
> > > SP/SC bulk enq/dequeue (size 8) | -0.36
> > > MP/MC bulk enq/dequeue (size 8) | 0.99
> > > SP/SC bulk enq/dequeue (size 32) | -0.40 MP/MC bulk enq/dequeue (size
> > > 32) | -0.57
> > >
> > > Two physical cores:
> > > SP/SC bulk enq/dequeue (size 8) | -0.49
> > > MP/MC bulk enq/dequeue (size 8) | 0.19
> > > SP/SC bulk enq/dequeue (size 32) | -0.28 MP/MC bulk enq/dequeue (size
> > > 32) | -0.62
> > >
> > > Two NUMA nodes:
> > > SP/SC bulk enq/dequeue (size 8) | 3.25
> > > MP/MC bulk enq/dequeue (size 8) | 1.87
> > > SP/SC bulk enq/dequeue (size 32) | -0.44 MP/MC bulk enq/dequeue (size
> > > 32) | -1.10
> > >
> > > An earlier version of this patch changed the head and tail indexes to
> > > uint64_t, but that caused a performance drop on 32-bit builds. With
> > > uintptr_t, no performance difference is observed on an i686 build.
> > >
> > > Signed-off-by: Gage Eads <gage.eads@intel.com>
> > > ---
> >
> > You're breaking the ABI - version bump for affected libraries is needed.
> >
> > --
> > Thanks,
> > Anatoly
>
> If I'm reading the versioning guidelines correctly, I'll need to gate the changes with the RTE_NEXT_ABI macro and provide a deprecation notice, then after a full deprecation cycle we can revert that and bump the library version. Not to mention the 3 ML ACKs.
>
> I'll address this in v2.
My understanding is that RTE_NEXT_API method is not used any more. Replaced by rte_experimental.
But this kind of change is more of a flag day event. Which means it needs to be pushed
off to a release that is planned as an ABI break (usually once a year) which would
mean 19.11.
next prev parent reply other threads:[~2019-01-11 19:55 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-10 21:01 [dpdk-dev] [PATCH 0/6] Add non-blocking ring Gage Eads
2019-01-10 21:01 ` [dpdk-dev] [PATCH 1/6] ring: change head and tail to pointer-width size Gage Eads
2019-01-11 4:38 ` Stephen Hemminger
2019-01-11 19:07 ` Eads, Gage
2019-01-11 10:25 ` Burakov, Anatoly
2019-01-11 19:12 ` Eads, Gage
2019-01-11 19:55 ` Stephen Hemminger [this message]
2019-01-15 15:48 ` Eads, Gage
2019-01-11 10:40 ` Burakov, Anatoly
2019-01-11 10:58 ` Bruce Richardson
2019-01-11 11:30 ` Burakov, Anatoly
[not found] ` <20190111115851.GC3336@bricha3-MOBL.ger.corp.intel.com>
2019-01-11 19:27 ` Eads, Gage
2019-01-21 14:14 ` Burakov, Anatoly
2019-01-22 18:27 ` Eads, Gage
2019-01-10 21:01 ` [dpdk-dev] [PATCH 2/6] ring: add a non-blocking implementation Gage Eads
2019-01-10 21:01 ` [dpdk-dev] [PATCH 3/6] test_ring: add non-blocking ring autotest Gage Eads
2019-01-10 21:01 ` [dpdk-dev] [PATCH 4/6] test_ring_perf: add non-blocking ring perf test Gage Eads
2019-01-10 21:01 ` [dpdk-dev] [PATCH 5/6] mempool/ring: add non-blocking ring handlers Gage Eads
2019-01-13 13:43 ` Andrew Rybchenko
2019-01-10 21:01 ` [dpdk-dev] [PATCH 6/6] doc: add NB ring comment to EAL "known issues" Gage Eads
2019-01-11 2:51 ` Varghese, Vipin
2019-01-11 19:30 ` Eads, Gage
2019-01-14 0:07 ` Varghese, Vipin
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 0/5] Add non-blocking ring Gage Eads
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 1/5] ring: change head and tail to pointer-width size Gage Eads
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 2/5] ring: add a non-blocking implementation Gage Eads
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 3/5] test_ring: add non-blocking ring autotest Gage Eads
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 4/5] test_ring_perf: add non-blocking ring perf test Gage Eads
2019-01-15 23:52 ` [dpdk-dev] [PATCH v2 5/5] mempool/ring: add non-blocking ring handlers Gage Eads
2019-01-16 0:26 ` [dpdk-dev] [PATCH v2 0/5] Add non-blocking ring Stephen Hemminger
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 " Gage Eads
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 1/5] ring: add 64-bit headtail structure Gage Eads
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 2/5] ring: add a non-blocking implementation Gage Eads
2019-01-22 10:12 ` Ola Liljedahl
2019-01-22 14:49 ` Ola Liljedahl
2019-01-22 21:31 ` Eads, Gage
2019-01-23 10:16 ` Ola Liljedahl
2019-01-25 17:21 ` Eads, Gage
2019-01-28 10:35 ` Ola Liljedahl
2019-01-28 18:54 ` Eads, Gage
2019-01-28 22:31 ` Ola Liljedahl
2019-01-28 13:34 ` Jerin Jacob Kollanukkaran
2019-01-28 13:43 ` Ola Liljedahl
2019-01-28 14:04 ` Jerin Jacob Kollanukkaran
2019-01-28 14:06 ` Ola Liljedahl
2019-01-28 18:59 ` Eads, Gage
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 3/5] test_ring: add non-blocking ring autotest Gage Eads
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 4/5] test_ring_perf: add non-blocking ring perf test Gage Eads
2019-01-18 15:23 ` [dpdk-dev] [PATCH v3 5/5] mempool/ring: add non-blocking ring handlers Gage Eads
2019-01-22 9:27 ` [dpdk-dev] [PATCH v3 0/5] Add non-blocking ring Ola Liljedahl
2019-01-22 10:15 ` Ola Liljedahl
2019-01-22 19:15 ` Eads, Gage
2019-01-23 16:02 ` Jerin Jacob Kollanukkaran
2019-01-23 16:29 ` Ola Liljedahl
2019-01-28 13:10 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-01-25 5:20 ` [dpdk-dev] " Honnappa Nagarahalli
2019-01-25 17:42 ` Eads, Gage
2019-01-25 17:56 ` Eads, Gage
2019-01-28 10:41 ` Ola Liljedahl
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 " Gage Eads
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 1/5] ring: add 64-bit headtail structure Gage Eads
2019-01-29 12:56 ` Ola Liljedahl
2019-01-30 4:26 ` Eads, Gage
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 2/5] ring: add a non-blocking implementation Gage Eads
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 3/5] test_ring: add non-blocking ring autotest Gage Eads
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 4/5] test_ring_perf: add non-blocking ring perf test Gage Eads
2019-01-28 18:14 ` [dpdk-dev] [PATCH v4 5/5] mempool/ring: add non-blocking ring handlers Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 0/6] Add lock-free ring and mempool handler Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 1/6] ring: add a pointer-width headtail structure Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 2/6] ring: add a ring start marker Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 3/6] ring: add a lock-free implementation Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 4/6] test_ring: add lock-free ring autotest Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 5/6] test_ring_perf: add lock-free ring perf test Gage Eads
2019-03-05 17:40 ` [dpdk-dev] [PATCH v5 6/6] mempool/ring: add lock-free ring handlers Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 0/6] Add lock-free ring and mempool handler Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 1/6] ring: add a pointer-width headtail structure Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 2/6] ring: add a ring start marker Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 3/6] ring: add a lock-free implementation Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 4/6] test_ring: add lock-free ring autotest Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 5/6] test_ring_perf: add lock-free ring perf test Gage Eads
2019-03-06 15:03 ` [dpdk-dev] [PATCH v6 6/6] mempool/ring: add lock-free ring handlers Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 0/6] Add lock-free ring and mempool handler Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 1/6] ring: add a pointer-width headtail structure Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 2/6] ring: add a ring start marker Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 3/6] ring: add a lock-free implementation Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-19 15:50 ` Stephen Hemminger
2019-03-19 15:50 ` Stephen Hemminger
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 4/6] test_ring: add lock-free ring autotest Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 5/6] test_ring_perf: add lock-free ring perf test Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:35 ` [dpdk-dev] [PATCH v7 6/6] mempool/ring: add lock-free ring handlers Gage Eads
2019-03-18 21:35 ` Gage Eads
2019-03-18 21:49 ` [dpdk-dev] [PATCH v7 0/6] Add lock-free ring and mempool handler Eads, Gage
2019-03-18 21:49 ` Eads, Gage
2019-03-19 15:51 ` Stephen Hemminger
2019-03-19 15:51 ` Stephen Hemminger
2019-04-01 19:23 ` Eads, Gage
2019-04-01 19:23 ` Eads, Gage
2019-04-02 10:16 ` Ola Liljedahl
2019-04-02 10:16 ` Ola Liljedahl
2019-04-04 22:28 ` Eads, Gage
2019-04-04 22:28 ` Eads, Gage
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 " Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 1/6] ring: add a pointer-width headtail structure Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 2/6] ring: add a ring start marker Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 3/6] ring: add a lock-free implementation Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 4/6] test_ring: add lock-free ring autotest Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 5/6] test_ring_perf: add lock-free ring perf test Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-03-19 1:20 ` [dpdk-dev] [PATCH v8 6/6] mempool/ring: add lock-free ring handlers Gage Eads
2019-03-19 1:20 ` Gage Eads
2019-04-03 16:46 ` [dpdk-dev] [PATCH v8 0/6] Add lock-free ring and mempool handler Thomas Monjalon
2019-04-03 16:46 ` Thomas Monjalon
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