DPDK patches and discussions
 help / color / mirror / Atom feed
From: "Eads, Gage" <gage.eads@intel.com>
To: Stephen Hemminger <stephen@networkplumber.org>
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: Tue, 15 Jan 2019 15:48:45 +0000	[thread overview]
Message-ID: <9184057F7FC11744A2107296B6B8EB1E541C71B3@FMSMSX108.amr.corp.intel.com> (raw)
In-Reply-To: <20190111115515.524273ae@hermes.lan>



> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Friday, January 11, 2019 1:55 PM
> To: Eads, Gage <gage.eads@intel.com>
> Cc: Burakov, Anatoly <anatoly.burakov@intel.com>; dev@dpdk.org;
> 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 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.

In recent release notes, I see ABI changes can happen more frequently than once per year; 18.11, 18.05, 17.11, and 17.08 have ABI changes -- and soon 19.02 will too.

At any rate, I'll create a separate deprecation notice patch and update this patchset accordingly.

Thanks,
Gage

  reply	other threads:[~2019-01-15 15:48 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
2019-01-15 15:48         ` Eads, Gage [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=9184057F7FC11744A2107296B6B8EB1E541C71B3@FMSMSX108.amr.corp.intel.com \
    --to=gage.eads@intel.com \
    --cc=anatoly.burakov@intel.com \
    --cc=arybchenko@solarflare.com \
    --cc=bruce.richardson@intel.com \
    --cc=dev@dpdk.org \
    --cc=konstantin.ananyev@intel.com \
    --cc=olivier.matz@6wind.com \
    --cc=stephen@networkplumber.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).