That was scary

[David Brown]

On 12/04/2020 21:28, Ricky C wrote:

On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown wrote:
On 12/04/2020 04:52, Ricky C wrote:

That's your straw man argument. We don't need a vaccine if we
can eliminate the virus. Do they still vaccinate for smallpox?


Smallpox was eliminated by vaccines - so we don't need vaccines for
it /now/.

So you are agreeing with me that if we eliminate the virus we won't
need a vaccine?

Yes - but I am also saying that you need a vaccine to eliminate it. I
don't think it will be practical to do so without a vaccine - it has
spread too far and wide to be contained.

Some diseases are hard to eradicate because they live in other
animals or even the soil like anthrax. We don't know where the crap
Ebola comes from.

Bats are the prime candidate for Ebola and related viruses, but it is
not known for sure.

But coronavirus? Yeah, it may have leapt from
another animal previously, but there is no indication we are being
reinfected by the same means. Get rid of it in humans and we will be
rid of it forever.

Hopefully, yes.

It is likely that this particular Corona virus was the result of a
mutation or combination from one or more other corona viruses. Whether
that occurred in a human or an animal is unknown. But if it were an
animal and it hasn't spread to other animals, then maybe it is only
significantly infectious in humans and therefore could be eliminated.
(It has been found in some other animals, but only a few, and their
infectiousness is not yet known.)

Not an easy task, but once we get the infection numbers down,
aggressive contact tracing has a lot less impact than the shutdown we
are presently in.

I don't believe it is realistic to get good enough testing and tracking
world-wide in order to eliminate it completely without mass vaccination.
It could certainly be controllable, but not eliminated.

(This is my estimation and extrapolation, rather than a known fact.)

Remember, recovery from Covid-19 does not appear to give very good
immunity - so all you need is a few pockets of it hidden away somewhere,
and the potential for new outbreaks will be there.

(One can hope that they would be caught and isolated faster now, of course.)

Measles was almost eliminated by vaccines, but there so many
"anti-vaxer" morons that the elimination failed, and there are
still outbreaks - so kids still need the vaccines. The same
applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines. Whether it
will or not is another matter - but good vaccines will certainly
prevent it being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I don't think
so. It is far too wide-spread for that. It can be kept at bay by
other measures, and some places can be kept free of it, but if
there is freedom of movement, outbreaks will always return.

Wide spread is not the issue. The shutdown will allow us to get the
numbers to a point that contact tracing can confine the disease.

If South Korea can do it, why can't we?

Because you are only one country. To eliminate the virus anywhere, it
needs to be eliminated /everywhere/. Maybe the USA can do the kind of
tracking that South Korea managed (I doubt it - Americans are not as
obedient. Freedom works both ways). But you won't get that same
tracking across India, Africa, war-torn Syria, Afghanistan, etc.

 

On Sun, 12 Apr 2020 20:10:37 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

On Sunday, April 12, 2020 at 4:51:33 PM UTC-7, jla...@highlandsniptechnology.com wrote:

Can no country ever release lockdown?

Sure. China , South Korea have basically done it.

Can the world survive years of lockdown?

The Four Horsemen of the Apocalypse include war, famine, disease, pestilence.
There's no horseman for lockdown, so I'd say probably yes.

Worldwide, or nation-wide, one would not see a single protocol in place; you clamp down
the highest propogation-rate sites as they become infected, using emergency powers,
and when the emergency goes away, so do the lockdowns.

But won't the epidemic return as soon as the lockdown is lifted? If
not, why not?



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[David Brown]

On 13/04/2020 03:39, dagmargoodboat@yahoo.com wrote:

On Sunday, April 12, 2020 at 12:19:24 PM UTC-4, David Brown wrote:
On 11/04/2020 17:21, jlarkin@highlandsniptechnology.com wrote:

When I did more realtime programming, I generally knew how long it
would take for a chunk of code to execute. Kids these days haven't the
faintest idea, and are afraid to push interrupt rates or state machine
rep rates. Sometimes I have to get an oscilloscope and show them how
fast a 600 MHz dual-core ARM can really compute. We got some
interesting numbers on the Zynq+Linux.

You claim this, and yet you don't think programming involves science,
causality, maths or system dynamics? Is that because you simply don't
understand what those terms mean? Or that you are lying about the
programming you have done? Or that you think /you/ have done "real"
programming, but no one else does? Or - and I strongly suspect this -
you are a troll who finds perverse entertainment in annoying people by
saying blatantly stupid things.

You're way off base.

John, being a solid programmer -- I've seen his code, and he's posted
code here, too -- just has a palpable disdain for what Bill Gates has
turned the 'discipline' into.

(You can tell a lot about a person, reading their code. You can see
if someone's clear-headed and reasoning, or confused and fiddling,
for one.)

I can agree that a lot of programs are written poorly.

But John basically said "You're a programmer? That means you don't do
any maths, science or rational work, and are probably just an English
major".

Mind you, he demonstrates himself that it is possible to write programs
while not understanding science or being able to reason rationally.

As I said, he is no doubt just trolling.

 

[David Brown]

On 13/04/2020 01:23, Ricky C wrote:

On Sunday, April 12, 2020 at 7:15:28 PM UTC-4, Clifford Heath wrote:
On 13/4/20 3:44 am, jlarkin@highlandsniptechnology.com wrote:

Many countries have peaked and declined, with a small fraction of
the population known to have been infected.

But those countries have not yet released lock-down and opened to
international travel. As soon as they do, it will be off like a
rocket again.

Not if they use effective case tracing. Oh, and they may have to
limit outside travel.

The virus got away from most countries because they were essentially
caught off guard. Now we know much more about it and can prevent the
spread if the numbers become manageable again.

This is not fundamentally different from managing any other
infectious disease. It may be easier to spread, but once we get the
number of cases down, we should be able to keep it confined.

It's just a tragedy that we are going to see so many deaths before we
get this under control when we watched it happen in China and then
did nothing to prevent the spread here as it grew all across the
country.

While I agree with all that, it is important to note that a lot of
countries are unable to do the kind of tracking and isolation necessary
no matter how much notice they get.

Perhaps I am being pessimistic here, but I think that all we can do is
control it where possible, limit the spread as much as we can, develop
good therapeutics (rather than guessing from anecdotes), all while
working towards a good mass-produced vaccine.

 

[David Brown]

On 12/04/2020 19:31, jlarkin@highlandsniptechnology.com wrote:

On Sun, 12 Apr 2020 18:27:39 +0200, David Brown
david.brown@hesbynett.no> wrote:

On 12/04/2020 04:52, Ricky C wrote:

That's your straw man argument. We don't need a vaccine if we can
eliminate the virus. Do they still vaccinate for smallpox?


Smallpox was eliminated by vaccines - so we don't need vaccines for it
/now/.

Measles was almost eliminated by vaccines, but there so many
"anti-vaxer" morons that the elimination failed, and there are still
outbreaks - so kids still need the vaccines. The same applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines. Whether it will or
not is another matter - but good vaccines will certainly prevent it
being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I don't think so.
It is far too wide-spread for that. It can be kept at bay by other
measures, and some places can be kept free of it, but if there is
freedom of movement, outbreaks will always return.



We can truly eradicate a virus that infects only humans. Smallpox,
polio, measles. Influenza and corona can jump species.

Yes, but even viruses that can jump species can be eliminated in humans.
You have to keep vaccinating, generation after generation. (Note that
influenza and corona are not viruses - they are groups of viruses.
Current vaccines for them target specific viruses in those families,
rather than covering the whole groups.)

Coronavirus epidemics of various sizes hit most every year. They die
out without vaccination, and a new strain appears next cold season.

https://en.wikipedia.org/wiki/Coronavirus#Evolution

There are lots of different corona virus, most of which are fairly
harmless. Covid-19 is caused by one specific type.

 

On Mon, 13 Apr 2020 16:35:13 +0200, David Brown
<david.brown@hesbynett.no> wrote:

On 13/04/2020 03:39, dagmargoodboat@yahoo.com wrote:
On Sunday, April 12, 2020 at 12:19:24 PM UTC-4, David Brown wrote:
On 11/04/2020 17:21, jlarkin@highlandsniptechnology.com wrote:

When I did more realtime programming, I generally knew how long it
would take for a chunk of code to execute. Kids these days haven't the
faintest idea, and are afraid to push interrupt rates or state machine
rep rates. Sometimes I have to get an oscilloscope and show them how
fast a 600 MHz dual-core ARM can really compute. We got some
interesting numbers on the Zynq+Linux.

You claim this, and yet you don't think programming involves science,
causality, maths or system dynamics? Is that because you simply don't
understand what those terms mean? Or that you are lying about the
programming you have done? Or that you think /you/ have done "real"
programming, but no one else does? Or - and I strongly suspect this -
you are a troll who finds perverse entertainment in annoying people by
saying blatantly stupid things.

You're way off base.

John, being a solid programmer -- I've seen his code, and he's posted
code here, too -- just has a palpable disdain for what Bill Gates has
turned the 'discipline' into.

(You can tell a lot about a person, reading their code. You can see
if someone's clear-headed and reasoning, or confused and fiddling,
for one.)


I can agree that a lot of programs are written poorly.

But John basically said "You're a programmer? That means you don't do
any maths, science or rational work, and are probably just an English
major".

Mind you, he demonstrates himself that it is possible to write programs
while not understanding science or being able to reason rationally.

As I said, he is no doubt just trolling.

No, seriously, most programmers use no math, no theory, don't know how
fast their code executes, and have never heard of a state machine or a
filter or signal averaging to reduce noise. Never heard of the
Sampling Theorem. They never write a routine that runs correctly first
try, and rarely manage one that even compiles error-free first time.

Our typical PC board has 6 or 8 layers, hundreds of analog and digital
parts, transmission lines and power supplies and connectors and FPGAs.
We don't prototype. We design and formally release the first rev to
manufacturing, they build a few, we qualify them, and we expect them
to work and be sellable. We can't click "compile" and see what
happens.

I hate to say this, but we need some way to program computers that is
not procedural messes of text and punctuation. Something more like
LabView for the mass of programmers.

If a scientist or an engineer writes a program to solve a mathematical
problem, sure she'll implement math. But few programmers ever do.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

On Mon, 13 Apr 2020 13:22:37 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 13/4/20 9:51 am, jlarkin@highlandsniptechnology.com wrote:
Can the world survive years of lockdown?

Globalism can't. Countries that aren't mostly self-sufficient can't.

Australia has a lot of work to do to rebuild local industries. I suspect
the USA does too, but not as much. You've got local skills everywhere,
much more than we do; our manufacturing has been gutted for so long that
most of the kids have never even seen someone using a lathe or a welder,
or has repaired their bike. An entire generation has grown up playing
video games instead of tinkering in the shed, and they've turned into
bloody useless "engineers". The genuine article is almost extinct.

CH

What does Australia do to feed and cloth and internet its population?
I mean, besides export coal and bad beer?

We have a lathe and two milling machines and a megabuck of
pick-and-place line. It's handy to have that stuff in-house. Next step
will be a 50-watt fiber laser.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Bill Sloman]

On Tuesday, April 14, 2020 at 1:12:45 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Mon, 13 Apr 2020 16:35:13 +0200, David Brown
david.brown@hesbynett.no> wrote:

On 13/04/2020 03:39, dagmargoodboat@yahoo.com wrote:
On Sunday, April 12, 2020 at 12:19:24 PM UTC-4, David Brown wrote:
On 11/04/2020 17:21, jlarkin@highlandsniptechnology.com wrote:

I can agree that a lot of programs are written poorly.

But John basically said "You're a programmer? That means you don't do
any maths, science or rational work, and are probably just an English
major".

Mind you, he demonstrates himself that it is possible to write programs
while not understanding science or being able to reason rationally.

As I said, he is no doubt just trolling.

No, seriously, most programmers use no math, no theory, don't know how
fast their code executes, and have never heard of a state machine or a
filter or signal averaging to reduce noise. Never heard of the
Sampling Theorem. They never write a routine that runs correctly first
try, and rarely manage one that even compiles error-free first time.

This is supposed to be a a serious statement about "most programmers"?

One has to imagine that John Larkin pays his programmers rock-bottom rates, and is suffering from the "pay peanuts, get code monkeys" effect.

<snipped the usual advertising>

I hate to say this, but we need some way to program computers that is
not procedural messes of text and punctuation. Something more like
LabView for the mass of programmers.

Serious programmers don't think much of LabView.

If a scientist or an engineer writes a program to solve a mathematical
problem, sure she'll implement math. But few programmers ever do.

Depends what you mean by a "programmer", and probably what you understand by "math".

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, April 14, 2020 at 12:41:19 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Sun, 12 Apr 2020 20:10:37 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Sunday, April 12, 2020 at 4:51:33 PM UTC-7, jla...@highlandsniptechnology.com wrote:

Can no country ever release lockdown?

Sure. China , South Korea have basically done it.

Can the world survive years of lockdown?

The Four Horsemen of the Apocalypse include war, famine, disease, pestilence.
There's no horseman for lockdown, so I'd say probably yes.

Worldwide, or nation-wide, one would not see a single protocol in place; you clamp down the highest propogation-rate sites as they become infected, using emergency powers, and when the emergency goes away, so do the lockdowns.

But won't the epidemic return as soon as the lockdown is lifted? If
not, why not?

The epidemic might start some place after the lockdown is lifted , but as long as the health services are watching out for it, and testing anything that looks remotely suspicious, it won't infect more than a few people and the surrounding area will get locked down hard enough that it won't infect anybody else.

As a bunch of places have demonstrated, an epidemic only grows as long as you let it. The US doesn't seem to have mastered the art of stopping an epidemic quickly, but it ought to be able to learn how, eventually. You may need to replace the current administation - they seem to learn remarkably slowly - but it is clearly possible.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Tuesday, April 14, 2020 at 12:47:15 AM UTC+10, jla...@highlandsniptechnology.com wrote:

On Mon, 13 Apr 2020 13:22:37 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 9:51 am, jlarkin@highlandsniptechnology.com wrote:
Can the world survive years of lockdown?

Globalism can't. Countries that aren't mostly self-sufficient can't.

Australia has a lot of work to do to rebuild local industries. I suspect
the USA does too, but not as much. You've got local skills everywhere,
much more than we do; our manufacturing has been gutted for so long that
most of the kids have never even seen someone using a lathe or a welder,
or has repaired their bike. An entire generation has grown up playing
video games instead of tinkering in the shed, and they've turned into
bloody useless "engineers". The genuine article is almost extinct.

Bizarre delusion.

> What does Australia do to feed and cloth and internet its population?

We grow enough food to feed about 75 million people and export about two-thirds of it. Australian claims to have invented WiFi - the Commonwealth Scientific and Industrial Research Organisation is reputed to have patents on it.

https://en.wikipedia.org/wiki/John_O%27Sullivan_(engineer)

> I mean, besides export coal and bad beer?

We keep the good beer and drink it ourselves. You forgot about the iron ore and the natural gas

We have a lathe and two milling machines and a megabuck of
pick-and-place line. It's handy to have that stuff in-house. Next step
will be a 50-watt fiber laser.

How impressive. But only one lathe? And no drill press?

--
Bill Sloman, Sydney

 

[Ricky C]

On Monday, April 13, 2020 at 10:25:05 AM UTC-4, David Brown wrote:

On 12/04/2020 21:28, Ricky C wrote:
On Sunday, April 12, 2020 at 12:27:45 PM UTC-4, David Brown wrote:
On 12/04/2020 04:52, Ricky C wrote:

That's your straw man argument. We don't need a vaccine if we
can eliminate the virus. Do they still vaccinate for smallpox?


Smallpox was eliminated by vaccines - so we don't need vaccines for
it /now/.

So you are agreeing with me that if we eliminate the virus we won't
need a vaccine?

Yes - but I am also saying that you need a vaccine to eliminate it. I
don't think it will be practical to do so without a vaccine - it has
spread too far and wide to be contained.

That is the fallacy in your argument. Being spread "far and wide" means nothing. Once this infection is under control and it is eliminated in a given area, it only requires a few things to remain free of the virus. I've already said all that.

But coronavirus? Yeah, it may have leapt from
another animal previously, but there is no indication we are being
reinfected by the same means. Get rid of it in humans and we will be
rid of it forever.

Hopefully, yes.

It is likely that this particular Corona virus was the result of a
mutation or combination from one or more other corona viruses. Whether
that occurred in a human or an animal is unknown. But if it were an
animal and it hasn't spread to other animals, then maybe it is only
significantly infectious in humans and therefore could be eliminated.
(It has been found in some other animals, but only a few, and their
infectiousness is not yet known.)

Ok, so now you are changing your story of the vaccine being essential?

Not an easy task, but once we get the infection numbers down,
aggressive contact tracing has a lot less impact than the shutdown we
are presently in.


I don't believe it is realistic to get good enough testing and tracking
world-wide in order to eliminate it completely without mass vaccination.
It could certainly be controllable, but not eliminated.

I only care about "controlling" it in this country. I believe that all the more modern countries will contain it and eliminate it within their borders. The other countries will essentially let it "burn out" which will take some time, but after a year or so the infection rates should be so low as to not pose significant threats. Travel bans can be lifted and contact tracing be the only means needed.

(This is my estimation and extrapolation, rather than a known fact.)

Remember, recovery from Covid-19 does not appear to give very good
immunity - so all you need is a few pockets of it hidden away somewhere,
and the potential for new outbreaks will be there.

(One can hope that they would be caught and isolated faster now, of course.)

Where did you see any indication that the disease does not leave the person immune? I have not seen that at all.

Measles was almost eliminated by vaccines, but there so many
"anti-vaxer" morons that the elimination failed, and there are
still outbreaks - so kids still need the vaccines. The same
applies to polio.

Covid-19 can, hopefully, be eliminated by vaccines. Whether it
will or not is another matter - but good vaccines will certainly
prevent it being a problem.

But can Covid-19 be eliminated /without/ a vaccine? I don't think
so. It is far too wide-spread for that. It can be kept at bay by
other measures, and some places can be kept free of it, but if
there is freedom of movement, outbreaks will always return.

Wide spread is not the issue. The shutdown will allow us to get the
numbers to a point that contact tracing can confine the disease.

If South Korea can do it, why can't we?


Because you are only one country. To eliminate the virus anywhere, it
needs to be eliminated /everywhere/. Maybe the USA can do the kind of
tracking that South Korea managed (I doubt it - Americans are not as
obedient. Freedom works both ways). But you won't get that same
tracking across India, Africa, war-torn Syria, Afghanistan, etc.

Ah, you are arguing semantics. Ok, fine. I'm talking about eliminating it in various countries that are capable. The rest of the world will deal with it for a while longer and have many more deaths, but even there this disease will pass once it infects enough people.

I suppose it could mutate and become infectious again after passing through the lion's share of the world community. But technically that is a new disease and a vaccine won't protect from that either. Perhaps they will crack the code on developing a vaccine to a slowly evolving antigen on the virus, but we've not been able to do that with the cold or flu.

Even vaccines are no match for an evolving virus.

--

Rick C.

--+- Get 1,000 miles of free Supercharging
--+- Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Monday, April 13, 2020 at 7:41:19 AM UTC-7, jla...@highlandsniptechnology.com wrote:

On Sun, 12 Apr 2020 20:10:37 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Sunday, April 12, 2020 at 4:51:33 PM UTC-7, jla...@highlandsniptechnology.com wrote:

Can no country ever release lockdown?

Sure. China , South Korea have basically done it.

But won't the epidemic return as soon as the lockdown is lifted? If
not, why not?

Lockdown removes personal contact that transmits the disease. The course of the
illness has a period of transmissibility. When that period is past, lockdown is unnecessary.

Honestly, though, there could be a 'typhoid mary' scenario where someone, somewhere,
just carries the disease but does NOT pass through that phase. Wuhan has opened back
up, and we may be finding out that this is possible.

"Typhoid Mary" Mallon was incarcerated for many years. Her persistent transmission of
the disease was anomalous, and such a phenomenon is unpredictable.

 

[Ricky C]

On Monday, April 13, 2020 at 1:57:06 PM UTC-4, whit3rd wrote:

On Monday, April 13, 2020 at 7:41:19 AM UTC-7, jla...@highlandsniptechnology.com wrote:
On Sun, 12 Apr 2020 20:10:37 -0700 (PDT), whit3rd <whit3rd@gmail.com
wrote:

On Sunday, April 12, 2020 at 4:51:33 PM UTC-7, jla...@highlandsniptechnology.com wrote:

Can no country ever release lockdown?

Sure. China , South Korea have basically done it.


But won't the epidemic return as soon as the lockdown is lifted? If
not, why not?

Lockdown removes personal contact that transmits the disease. The course of the
illness has a period of transmissibility. When that period is past, lockdown is unnecessary.

Honestly, though, there could be a 'typhoid mary' scenario where someone, somewhere,
just carries the disease but does NOT pass through that phase. Wuhan has opened back
up, and we may be finding out that this is possible.

I'm not clear on how this disease has a "period of transmissibility". If anyone is infected, they can transmit the disease to others.

Once the lockdown is ended in a given area, the disease will return unless measures are taken to prevent it. We've gone over this many, many times here. Travel will need to be restricted for some time after the lock down is ended, but most importantly, case tracking will need to be done on every single case. If that is done effectively we will be able to resume activities. It would remain a good idea to continue social distancing rules until the disease is completely eradicated at least from the country you are in.

One problem is all the many people who are in denial of the seriousness of this disease. We continue to hear reports of people being fined for not obeying lock down orders and social distancing rules. Once we are at a low enough infection level that we can relax the shut down rules, why do we think many people will continue to obey the remaining rules?

The forecasts are now showing we are nearing the peak and our efforts at social distancing have been fairly effective other than perhaps in New York. Each area of the country is different however. But even in the areas with slower progression of the disease, the peak will be over by the end of April. It is looking like the end of May might be a time when the US can start to relax the lock down without worrying about a rebound. I expect this will happen much sooner and we will see a rebound in areas.

--

Rick C.

--++ Get 1,000 miles of free Supercharging
--++ Tesla referral code - https://ts.la/richard11209

 

[John Larkin]

On Mon, 13 Apr 2020 12:13:35 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 13/4/20 12:07 pm, jlarkin@highlandsniptechnology.com wrote:
On Mon, 13 Apr 2020 09:33:14 +1000, Clifford Heath
I should drag out tprof again, it still fills a need that's
substantially un-met by existing tools. It also contained a dynamic
memory profiling mode that was useful.

Sometimes we raise a port pin at the entry of a chunk of code and drop
it at the end, and look at that with an oscilloscope. A routine can be
optimized for worst-case execution time, which usually matters more
than average. A little thinking can sometimes reduce worst-case by
5:1.

One port pin can be made to blip or change state at several places in
a segment of code. That can look cool on infinite persistance.

Great way to look at exactly one thing at a time, and quite unlike what
a proper profiler does.

I have histogrammed the program counter. That can be a revelation. See
what's hogging the resources.

That's a trivial profiler, and comes built-in to Linux tools, always has
(since 1976 at least). It tells you nothing about context switch or
interrupt latencies though, because it only samples during the program's
assigned timeslots i.e. while it's running.

CH

Nobody has guessed about the Linux timeouts I measured. Nobody has
estimated a reasonable IRQ rate for my tiny ARM. An oscilloscope is
good enough for things like that.

I guess there are no realtime programmers here. Some people don't know
a millisecond from a microsecond. Really!

I have a friend who is a Fellow with Collins. He's a software genius,
but doesn't know which end of an oscilloscope is which.



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[whit3rd]

On Monday, April 13, 2020 at 11:50:00 AM UTC-7, Ricky C wrote:

> I'm not clear on how this disease has a "period of transmissibility". If anyone is infected, they can transmit the disease to others.

That's a chicken-and-egg situation, though. Our test for 'is infected' is for viable
virus in discharges/accessible body fluids.

 

[Clifford Heath]

On 14/4/20 12:47 am, jlarkin@highlandsniptechnology.com wrote:

On Mon, 13 Apr 2020 13:22:37 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 9:51 am, jlarkin@highlandsniptechnology.com wrote:
Can the world survive years of lockdown?

Globalism can't. Countries that aren't mostly self-sufficient can't.

Australia has a lot of work to do to rebuild local industries. I suspect
the USA does too, but not as much. You've got local skills everywhere,
much more than we do; our manufacturing has been gutted for so long that
most of the kids have never even seen someone using a lathe or a welder,
or has repaired their bike. An entire generation has grown up playing
video games instead of tinkering in the shed, and they've turned into
bloody useless "engineers". The genuine article is almost extinct.

What does Australia do to feed and cloth and internet its population?

Buy from China, the same way the USA does.

> I mean, besides export coal and bad beer?

You want us to export the good beer? No thanks, we're drinking that here!

We export a lot of high grade iron ore, and also LNG. And food.

We used to manufacture electronics, whitegoods, cars, and many other
things, but it's all been shut down. We have to reverse that.

CH

 

[Clifford Heath]

On 14/4/20 10:23 am, John Larkin wrote:

On Tue, 14 Apr 2020 09:57:56 +1000, Clifford Heath
no.spam@please.net> wrote:
On 14/4/20 12:47 am, jlarkin@highlandsniptechnology.com wrote:
What does Australia do to feed and cloth and internet its population?

Buy from China, the same way the USA does.

I mean, besides export coal and bad beer?
You want us to export the good beer? No thanks, we're drinking that here!

We export a lot of high grade iron ore, and also LNG. And food.

We used to manufacture electronics, whitegoods, cars, and many other
things, but it's all been shut down. We have to reverse that.
Does Australia have any sort of academic/technology niche?

Education is our 3rd largest export (the amount is mostly
education-related travel), and the largest services export.

Niche? I believe we have quite a lot of very strong tech/research
capabilities (especially medical) but they're mostly rivalled by similar
ones elsewhere. There are a few distinctive things, but the history is
that they get moved offshore. Not sure if Cochlear (bionic ear) is in
that position yet - but many decades of world-leading research went into
it. As it did into Relenza, the world's first bio-engineered flu
vaccine. WiFi is another. And many similar cases in point.

We go and do deals with other countries (commonly USA) who generally
succeed in cheating us of the benefits.

CH.

 

[John Larkin]

On Tue, 14 Apr 2020 10:03:18 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 14/4/20 5:26 am, John Larkin wrote:
On Mon, 13 Apr 2020 12:13:35 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 12:07 pm, jlarkin@highlandsniptechnology.com wrote:
On Mon, 13 Apr 2020 09:33:14 +1000, Clifford Heath
I should drag out tprof again, it still fills a need that's
substantially un-met by existing tools. It also contained a dynamic
memory profiling mode that was useful.

Sometimes we raise a port pin at the entry of a chunk of code and drop
it at the end, and look at that with an oscilloscope. A routine can be
optimized for worst-case execution time, which usually matters more
than average. A little thinking can sometimes reduce worst-case by
5:1.

One port pin can be made to blip or change state at several places in
a segment of code. That can look cool on infinite persistance.

Great way to look at exactly one thing at a time, and quite unlike what
a proper profiler does.

I have histogrammed the program counter. That can be a revelation. See
what's hogging the resources.

That's a trivial profiler, and comes built-in to Linux tools, always has
(since 1976 at least). It tells you nothing about context switch or
interrupt latencies though, because it only samples during the program's
assigned timeslots i.e. while it's running.

CH

Nobody has guessed about the Linux timeouts I measured. Nobody has
estimated a reasonable IRQ rate for my tiny ARM. An oscilloscope is
good enough for things like that.

Sure! If it works for you, that's great.

On a running Linux system with normal desktop peripherals, there is a
great variety of different kinds of things going on. In the histogram of
latencies, it's very instructive to see the different spikes for
different interrupts (and try to identify which is which), and to see
the variance for each spike. Kind-of a top-down view, which would
augment your bottom-up one.

CH

We were interested in how long and how often a tight application loop
might be suspended by the OS and drivers and stuff. Would a profiler
tell you that?

We considered running Linux on one ARM in the Zynq, and running the
other ARM bare-metal. Turns out we didn't need to do that.

In a Zynq sort of chip, one bailout is to move "code" from the ARM
cpu's into FPGA fabric. I'm often shocked by what people can implement
in VHDL.



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Larkin]

On Tue, 14 Apr 2020 09:57:56 +1000, Clifford Heath
<no.spam@please.net> wrote:

On 14/4/20 12:47 am, jlarkin@highlandsniptechnology.com wrote:
On Mon, 13 Apr 2020 13:22:37 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 9:51 am, jlarkin@highlandsniptechnology.com wrote:
Can the world survive years of lockdown?

Globalism can't. Countries that aren't mostly self-sufficient can't.

Australia has a lot of work to do to rebuild local industries. I suspect
the USA does too, but not as much. You've got local skills everywhere,
much more than we do; our manufacturing has been gutted for so long that
most of the kids have never even seen someone using a lathe or a welder,
or has repaired their bike. An entire generation has grown up playing
video games instead of tinkering in the shed, and they've turned into
bloody useless "engineers". The genuine article is almost extinct.

What does Australia do to feed and cloth and internet its population?

Buy from China, the same way the USA does.

I mean, besides export coal and bad beer?

You want us to export the good beer? No thanks, we're drinking that here!

We export a lot of high grade iron ore, and also LNG. And food.

We used to manufacture electronics, whitegoods, cars, and many other
things, but it's all been shut down. We have to reverse that.

CH

Does Australia have any sort of academic/technology niche?

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Clifford Heath]

On 14/4/20 5:26 am, John Larkin wrote:

On Mon, 13 Apr 2020 12:13:35 +1000, Clifford Heath
no.spam@please.net> wrote:

On 13/4/20 12:07 pm, jlarkin@highlandsniptechnology.com wrote:
On Mon, 13 Apr 2020 09:33:14 +1000, Clifford Heath
I should drag out tprof again, it still fills a need that's
substantially un-met by existing tools. It also contained a dynamic
memory profiling mode that was useful.

Sometimes we raise a port pin at the entry of a chunk of code and drop
it at the end, and look at that with an oscilloscope. A routine can be
optimized for worst-case execution time, which usually matters more
than average. A little thinking can sometimes reduce worst-case by
5:1.

One port pin can be made to blip or change state at several places in
a segment of code. That can look cool on infinite persistance.

Great way to look at exactly one thing at a time, and quite unlike what
a proper profiler does.

I have histogrammed the program counter. That can be a revelation. See
what's hogging the resources.

That's a trivial profiler, and comes built-in to Linux tools, always has
(since 1976 at least). It tells you nothing about context switch or
interrupt latencies though, because it only samples during the program's
assigned timeslots i.e. while it's running.

CH

Nobody has guessed about the Linux timeouts I measured. Nobody has
estimated a reasonable IRQ rate for my tiny ARM. An oscilloscope is
good enough for things like that.

Sure! If it works for you, that's great.

On a running Linux system with normal desktop peripherals, there is a
great variety of different kinds of things going on. In the histogram of
latencies, it's very instructive to see the different spikes for
different interrupts (and try to identify which is which), and to see
the variance for each spike. Kind-of a top-down view, which would
augment your bottom-up one.

CH