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Groups > sci.physics.relativity > #671585
| From | Mild Shock <janburse@fastmail.fm> |
|---|---|
| Newsgroups | sci.physics.relativity, sci.math |
| Subject | Do you see the loops, in C code and in Java code? /** Looping **/ (Re: Because of MIMD you have to reassess algorithms) |
| Date | 2026-07-23 00:10 +0200 |
| Message-ID | <113rf5a$846i$2@solani.org> (permalink) |
| References | (12 earlier) <113mb62$4krr$1@solani.org> <113mcq5$1j9n2$2@dont-email.me> <113n4qm$5oih$2@solani.org> <113n5c6$5ouq$1@solani.org> <bomcnbKDMq5bv8L3nZ2dnZfqn_GdnZ2d@giganews.com> |
Cross-posted to 2 groups.
Hi,
CAS and XADD have no looping, they
are atomic operations, that take some
time but basically have some outcome
with some ACID property and a result
value. What loops is the ADT, the Abstract
Data Type that you implement. Respectively
the client that uses the Abstract Data Type.
In your case you added the loop inside the
Abstract Data Type or lower level aggregate
code of a higher level operation:
Chris M. Thomasson wrote:
void producer(double state) {
uint32_t ver = XADD(&head, 1);
cell& c = cells[ver & (N - 1)];
while (LOAD(&c.ver) != ver) backoff(); /** Looping **/
c.state = state;
STORE(&c.ver, ver + 1);
}
https://groups.google.com/g/lock-free/c/acjQ3-89abE/m/a6-Di0GZsyEJ
In my case I added the loop during the client
usage of the ADT:
From: Mild Shock <janburse@fastmail.fm>
Subject: Source of the benchmark for DmitryVyukov
Date: Tue, 21 Jul 2026 01:44:21 +0200
private static void producer(Queue q) {
for (int i = 0; i < WORK; i++) {
Integer val = Integer.valueOf(i);
while (!enqueue(q, val)) ; /** Looping **/
}
}
Do you see the two loops, in your C code
and in my Java code? They are marked with a
comment /** Looping **/ .
You see them, don't you? But I don't know
exactly what backoff() does. Sometimes loops
are spurious yield loops, required because
an ADT cannot gurantee that every yield
implies a certain condition. This is for
example already found in the intrinsinc
monitor of Java, the wait(). You might consult
Doug Lea about the matter and how idiomatic
Java code looks like dealing with
spurious yields.
Bye
Ross Finlayson schrieb:
> On 07/20/2026 11:59 PM, Mild Shock wrote:
>> Hi,
>>
>> Because of MIMD you have to reassess algorithms.
>> A spin loop which could really hurt non-MIMD
>> GPUs, might less hurt a MIMD GPU.
>>
>> Basically you have to reassess algorithms. Be
>> very exact whether your claims relates to
>> non-MIMD or to MIMD. You can toy around
>>
>> with WebGL, mainly made for non-MIMD, here:
>>
>> https://www.shadertoy.com/
>>
>> and with WegGPU, mainly made for MIMD, here:
>>
>> https://compute.toys/
>>
>> The compute toys page, supports two shader
>> languages, WGSL and Slang. I made my GPU
>> experiments only with WGSL.
>>
>> So I don't know Slang either. Things I
>> don't know in the GPU world are:
>>
>> - OpenGL 4.2 and later
>> - Slang https://shader-slang.org/
>>
>> Things I have meanwhile hands on, and which
>> I plan to integrate into library(edge/brainfog):
>>
>> - WGSL https://webgpufundamentals.org/
>>
>> Bye
>>
>> Mild Shock schrieb:
>>> Hi,
>>>
>>> I went to holdays in June 2026, had an idea for
>>> a pi-WAM based on a Hack, the later is described here:
>>>
>>> Emulating π-WAM in Dogelog Player
>>> https://medium.com/2989/de9cd29c7d37
>>>
>>> The Elements of Computing Systems
>>> https://mitpress.mit.edu/9780262539807
>>>
>>> In July 2026 I did the CPU and GPU experiments,
>>> moving from emulator to native executor based in
>>> realizing Hack as a concrete virtual machine,
>>>
>>> and not as an abstract machine emulated in Prolog.
>>> The GPU experiments were done in WebGPU / WGSL.
>>> So no, I never used OpenGL Version 4.2 and later.
>>>
>>> Also the name imageAtomicAdd indicates that
>>> imageAtomicAdd is rather from a render shader,
>>> while my GPU experiment uses a compute shader.
>>>
>>> Especially I need GPU compute shaders, which
>>> are not executed in lock step, but rather have
>>> indepdendent thread state, also known as MIMD.
>>>
>>> "In computing, multiple instruction, multiple
>>> data (MIMD) is a technique employed to
>>> achieve parallelism. "
>>> https://en.wikipedia.org/wiki/Multiple_instruction,_multiple_data
>>>
>>> MIMID showed up 2017 with NVIDIA Volta cards.
>>> But is now realized by Intel Arc, Snapdragon Adreno,
>>> AMD RDNA and Apple Silicon as well.
>>>
>>> Bye
>>>
>>> Chris M. Thomasson schrieb:
>>>> On 7/20/2026 4:32 PM, Mild Shock wrote:
>>>>> Hi,
>>>>>
>>>>> imageAtomicAdd is trivial, but it does
>>>>> not help with bounded buffers.
>>>> [...]
>>>>
>>>> Are you sure about that! ;^o
>>>
>>
>
> How about Silicon Grid Engine and MPI, OpenMP and old cluster.
>
>
> Or old "batch jobs".
>
> Batch jobs: it's how work gets done.
>
>
>
> You crazy frothing lunatic
>
>
>
Back to sci.physics.relativity | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) Mild Shock <janburse@fastmail.fm> - 2026-07-19 11:53 +0200
Corr.: Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) Mild Shock <janburse@fastmail.fm> - 2026-07-19 11:55 +0200
Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-19 14:04 -0700
Re: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM] (Was: Paul Tarau versus Mr. Taskmanager, who would win? [A PDP-11 Humunkulus from 1979]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-19 14:07 -0700
Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) Mild Shock <janburse@fastmail.fm> - 2026-07-20 08:31 +0200
Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) Romelio Balakhonsky <lrel@lao.ru> - 2026-07-20 10:07 +0000
The Cache Identity Crisis by Micro Penis (Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Mild Shock <janburse@fastmail.fm> - 2026-07-20 13:51 +0200
Just RTFM the RDNA 3.5 specs! [GPU Cache Lines] (Was: The Cache Identity Crisis by Micro Penis) Mild Shock <janburse@fastmail.fm> - 2026-07-20 14:09 +0200
The large memory tax: ECC RAM (Was: Just RTFM the RDNA 3.5 specs! [GPU Cache Lines]) Mild Shock <janburse@fastmail.fm> - 2026-07-20 14:22 +0200
Friendly Reminder: GPU 10x more performant than CPU (Re: Just RTFM the RDNA 3.5 specs! [GPU Cache Lines]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:40 +0200
Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:57 +0200
Like WebAssembly before it, WebGPU has "escaped" the browser. (Re: Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:07 +0200
Re: Breaking the CUDA edge in AI by WebGPU (Re: Friendly Reminder: GPU 10x more performant than CPU) Will Bakshandaev <bev@lwesi.ru> - 2026-07-21 14:33 +0000
http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:41 +0200
If you are paranoid you can use Falco [Agentic AI] (Re: http://localhost:567921/ is a private REST endpoint) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:57 +0200
What would an EMACs guru say [Windows Recall] (Was: If you are paranoid you can use Falco [Agentic AI]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 23:33 +0200
Re: http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Hants Baibikov <vi@bi.ru> - 2026-07-21 21:51 +0000
Re: http://localhost:567921/ is a private REST endpoint [Teaching Micro Penis Vilage Idiot] (Was: Breaking the CUDA edge in AI by WebGPU) Pascual Talbaev <ps@laalapa.ru> - 2026-07-21 22:02 +0000
Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Mild Shock <janburse@fastmail.fm> - 2026-07-22 08:13 +0200
How confused is tiny winy penis? (Re: Decide what you critique tiny winy penis) Mild Shock <janburse@fastmail.fm> - 2026-07-22 08:29 +0200
Maybe change your hobby, become a dog owner? (Re: How confused is tiny winy penis?) Mild Shock <janburse@fastmail.fm> - 2026-07-22 09:38 +0200
Re: Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Audie Balaban <aie@ndabl.ru> - 2026-07-22 08:02 +0000
Even dogs know Switzerland != Germany [Syphilis Brain Micro Penis] (Re: Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Mild Shock <janburse@fastmail.fm> - 2026-07-22 11:17 +0200
Re: Even dogs know Switzerland != Germany [Syphilis Brain Micro Penis] (Re: Decide what you critique tiny winy penis (Was: http://localhost:567921/ is a private REST endpoint) Roque Bahtinov <aoqhi@hrot.ru> - 2026-07-22 12:04 +0000
My Swift Go 16 AI has no IMEI, are you nuts? (Was: Even dogs know Switzerland != Germany [Syphilis Brain Micro Penis]) Mild Shock <janburse@fastmail.fm> - 2026-07-22 14:12 +0200
Same nickname and email, could post faster [5 year old moron] (Re: My Swift Go 16 AI has no IMEI, are you nuts?) Mild Shock <janburse@fastmail.fm> - 2026-07-22 14:24 +0200
Re: My Swift Go 16 AI has no IMEI, are you nuts? (Was: Even dogs know Switzerland != Germany [Syphilis Brain Micro Penis]) Randolf Mukanov <mfroa@unvfo.ru> - 2026-07-22 12:27 +0000
I have nothing to hide, you can find me in search.ch (Was: My Swift Go 16 AI has no IMEI, are you nuts?) Mild Shock <janburse@fastmail.fm> - 2026-07-22 14:31 +0200
Re: I have nothing to hide, you can find me in search.ch (Was: My Swift Go 16 AI has no IMEI, are you nuts?) Keiv Babenchikov <hi@babebek.ru> - 2026-07-22 12:35 +0000
Where did I confirm German via .ch, you are more than nuts! (Was: I have nothing to hide, you can find me in search.ch) Mild Shock <janburse@fastmail.fm> - 2026-07-22 14:46 +0200
Ask a Ukrainian Neighbour to do Detective [CCCP Troll] (Was: Where did I confirm German via .ch, you are more than nuts!) Mild Shock <janburse@fastmail.fm> - 2026-07-22 14:51 +0200
Re: Ask a Ukrainian Neighbour to do Detective [CCCP Troll] (Was: Where did I confirm German via .ch, you are more than nuts!) Hudson Patrianakos <nrin@odrtta.gr> - 2026-07-22 16:10 +0000
Re: The Cache Identity Crisis by Micro Penis (Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Jeiker Makulov <rmkru@eeeamu.ru> - 2026-07-20 16:18 +0000
L1,..,Ln caches are located on the CPU AND on the GPU (Was: The Cache Identity Crisis by Micro Penis) Mild Shock <janburse@fastmail.fm> - 2026-07-20 19:33 +0200
GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU) Mild Shock <janburse@fastmail.fm> - 2026-07-20 19:42 +0200
Re: GPU Cache Hierarchy: Understanding L1, L2, and VRAM (Re: L1,..,Ln caches are located on the CPU AND on the GPU) Zackee Mulatov <azauv@omtla.ru> - 2026-07-20 19:09 +0000
Well thats good, co-location, onto the same processor die (Was: GPU Cache Hierarchy: Understanding L1, L2, and VRAM) Mild Shock <janburse@fastmail.fm> - 2026-07-20 22:02 +0200
Where is micro penis mental error? (Re: Well thats good, co-location, onto the same processor die) Mild Shock <janburse@fastmail.fm> - 2026-07-20 22:07 +0200
Re: Well thats good, co-location, onto the same processor die (Was: GPU Cache Hierarchy: Understanding L1, L2, and VRAM) Hermis Molochkov <me@olech.ru> - 2026-07-20 22:27 +0000
Re: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov (Was: I'm a spinner, I'm a sinner [Dmitry Vyukov for pi-WAM]) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 13:40 -0700
I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) Mild Shock <janburse@fastmail.fm> - 2026-07-20 23:25 +0200
Re: I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 14:32 -0700
Re: I didn't find Futex in WebGPU / WGSL (Was: Gemini, DeepSeek, OpenAI all know Dmitriy V'jukov) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 14:35 -0700
There is no imageAtomicAdd in WGSL (Was: I didn't find Futex in WebGPU / WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:12 +0200
OpenGL is dead. Apple said bye bye / Wayland Compositor (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 00:24 +0200
Re: There is no imageAtomicAdd in WGSL (Was: I didn't find Futex in WebGPU / WGSL) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 16:15 -0700
Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:24 +0200
imageAtomicAdd trivial, Dmitry Vyukov requires capacity (Re: Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:32 +0200
capacity = 2^n for some n / systolic system (Was: imageAtomicAdd trivial, Dmitry Vyukov requires capacity) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:37 +0200
Source of the benchmark for DmitryVyukov (Re: capacity = 2^n for some n / systolic system) Mild Shock <janburse@fastmail.fm> - 2026-07-21 01:45 +0200
Re: imageAtomicAdd trivial, Dmitry Vyukov requires capacity (Re: Flogging a Dead Horse, OpenGL is EOL (Was: There is no imageAtomicAdd in WGSL) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-20 17:00 -0700
I never used OpenGL Version 4.2 and later (Re: imageAtomicAdd trivial, Dmitry Vyukov requires capacity) Mild Shock <janburse@fastmail.fm> - 2026-07-21 08:49 +0200
Because of MIMD you have to reassess algorithms (Was: I never used OpenGL Version 4.2 and later) Mild Shock <janburse@fastmail.fm> - 2026-07-21 08:59 +0200
Why MIMD is interesting for pi-WAM? Mild Shock <janburse@fastmail.fm> - 2026-07-21 09:16 +0200
Re: Why MIMD is interesting for pi-WAM? Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 00:32 -0700
Re: Because of MIMD you have to reassess algorithms (Was: I never used OpenGL Version 4.2 and later) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 00:42 -0700
You still don't understand "budget" [Rossy Boy slower than Micro Penis] (Was: Because of MIMD you have to reassess algorithms) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:13 +0200
Go on Rossy Boy, ask more stupid questions (Was: You still don't understand "budget" [Rossy Boy slower than Micro Penis]) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:17 +0200
Need to be Einstein to understand Giga Lips (Was: Go on Rossy Boy, ask more stupid questions) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:22 +0200
Marketing invents Gucci Bag AI Laptops (Was: Need to be Einstein to understand Giga Lips) Mild Shock <janburse@fastmail.fm> - 2026-07-21 10:43 +0200
Re: Go on Rossy Boy, ask more stupid questions (Was: You still don't understand "budget" [Rossy Boy slower than Micro Penis]) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 08:59 -0700
Rossy Boy says I am a crazy frothing lunatic (Was: Go on Rossy Boy, ask more stupid questions) Mild Shock <janburse@fastmail.fm> - 2026-07-21 22:27 +0200
Re: Rossy Boy says I am a crazy frothing lunatic (Was: Go on Rossy Boy, ask more stupid questions) Ross Finlayson <ross.a.finlayson@gmail.com> - 2026-07-21 13:52 -0700
Do you see the loops, in C code and in Java code? /** Looping **/ (Re: Because of MIMD you have to reassess algorithms) Mild Shock <janburse@fastmail.fm> - 2026-07-23 00:10 +0200
Re: Do you see the loops, in C code and in Java code? /** Looping **/ (Re: Because of MIMD you have to reassess algorithms) Lane W <cactus_DAC@yahoo.com> - 2026-07-22 16:23 -0600
regreting not using a contraceptive (Was: Do you see the loops, in C code and in Java code? /** Looping **/) Mild Shock <janburse@fastmail.fm> - 2026-07-23 00:51 +0200
Re: regreting not using a contraceptive (Was: Do you see the loops, in C code and in Java code? /** Looping **/) Lane W <cactus_DAC@yahoo.com> - 2026-07-22 17:13 -0600
Re: regreting not using a contraceptive (Was: Do you see the loops, in C code and in Java code? /** Looping **/) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-22 18:23 -0700
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