* Posts by Peter Gathercole

2924 posts • joined 15 Jun 2007

Scary code of the week: Valve Steam CLEANS Linux PCs (if you're not careful)

Peter Gathercole Silver badge

Re: What is the best practice here? @AC

I stand by every word I said. I do not think that your post is as clear as you think it is.

You cannot protect from stupidity, and setting world write to both the files and the directories (necessary to delete a file) is something that you only do if you can accept the scenario you outlined. Just because you have "experienced" developers does not mean that they don't follow bad practice ("developers" often play fast and lose with both good practice and security, claiming that both "get in the way" of being productive). And giving world write permissions to files and directories is in almost all cases overkill. Restrict the access by group if you want to share files, and give all the users appropriate group membership. It's been good practice for decades.

You did say "Frankly, if it had been running as root it would probably have trashed (and crashed) the test system before too much external harm was done", but this is probably not true. You did not actually point out that root would not traverse the mount point of the NFS mounted files, but you did say "starting at a root that encompassed the whole NFS-automounted user home directory", implying that it was not the root directory of the system that was being deleted, but just the NFS mounted filesystems.

From personal experience, I have actually seen UNIX systems continue to run damaging processes even after significant parts of their filesystems have been deleted. This is especially true if the command that is doing the damage is running as a monolithic process (like being written in a compiled language or an inclusive interpreted one like Perl, Python or many others) and using direct calls to the OS rather than calling the external utilities with "system".

Many sites have home directories mounted somewhere under /home, so if it were doing a ftw in collating sequence order from the system root, it would come across and traverse /home before it would /usr (the most likely place for missing files to affect a system), so even it it did run from the system root, enough of the system would continue to run whilst /home was traversed. Not so safe.

Peter Gathercole Silver badge

Re: What is the best practice here? @AC

And the problem here is typified by your statement 'could only delete the files that had suitable "other" permissions'.

Teach your users to set reasonable permissions on files! It goes back to my statement "too many people do not understand the inherent multi-user nature of UNIX-like operating systems".

With regard to running the script as root. You're not that familiar with NFS are you?

If you are using it properly, you will have the NFS export options set to prevent root access as root (it should be the default that you have to override), which is there to prevent exactly this sort of problem. This maps any attempt to use root on the test system into the 'nobody' user on the server, not root. Anybody who sets up a test server to have root permissions over any mounted production filesystem deserves every problem that they get!

There are people who have been using NFS in enterprise environments for in excess of quarter of a century. Do you not think that these problems have not been addressed before now?

Peter Gathercole Silver badge

Re: What is the best practice here?

Traditionally, in the UNIX world where you normally have more than one user on the system, you backup the system as root. Tools like tar, cpio and pax then record the ownership and permissions as they create the backup, and put them back when restoring files as root. This also allowed filesystems to be mounted and unmounted in the days before mechanisms to allow user-mounts were created.

The problem is that too many people do not understand the inherent multi-user nature of UNIX-like operating systems, and use them like PCs (as in single-user personal computers). To my horror, this includes many of the people developing applications and even distros maintainers!

There is nothing in UNIX or Linux that will prevent a process from damaging files owned by the user executing the process. But that is not too different from any common OS unless you take extraordinary measures (like carefully crafted ACLs). But at least running as a non-root user will prevent bad code like this from damaging the system as a whole.

Ex Machina – a smart, suspenseful satire of our technology gods

Peter Gathercole Silver badge

Re: Actually... @Destroy All Monsters

GiTS is all about the balance between artificial and natural conciousness. It's the main theme from both the film and the TV series, although it's more difficult to see in the original Manga.

There are AIs that aspire to be 'human' with the tachikomas and Project 2501, and AIs masquerading as humans as in Proto. And then you've got cyborgs who wonder whether they still count as human, Motoko and Bateau, with side stories of clones, ghost dubbing onto both clones and artificial bodies, and what being human actually means.

I've not seen this yet, but I seriously doubt that it really brings much more to the subject than what's in fiction already. It will likely be an aspirational story about wanting to be human and the trials it involves like Blade Runner, The Bicentennial Man, Demonseed or even in some respects, Disney's Little Mermaid. But I will look forward to seeing it when it hits Sky or the like.

Swots explain how to swat CPU SNITCHES

Peter Gathercole Silver badge

Re: In terms of doing anything useful

It strikes me that it is not feasible to do anything reasonable in real-time.

Chances are the amount of processing to identify an instruction from this information would require a processor much faster than the one being analysed. And even if you know the instruction, you don't know the data that it is operating on.

I suppose that if you could know the sequence of instructions used to encrypt the data, you may, in time and given enough examples of the calculation being performed, be able to reverse engineer it, but as most cryptography algorithms are available, the only thing I think you could work out is which method is being used.

So you can hack the region coding of a DVD or Bluray player like this, but this is nothing like being able to see everything that a computer is doing by it's emissions.

Peter Gathercole Silver badge

Re: Tin Foil is tha answer to the question @theodore

No, that was probably to comply with the FCC emissions regulations for consumer devices in the US, which were a real problem to the early home computer manufacturers.

Different manufacturers cam up with different solutions. Some made their computer's case out of metal. Some put full metal enclosures around the electronics inside a plastic case, and others used conductive paint sprayed onto or metal foil bonded to the inside of the plastic case.

I believe this is the main reason why many UK manufacturers had difficulty selling their systems in the US, because our emission regulations were much less strict.

Want a cheap Office-er-riffic tablet? Microsoft Windows takes on Android

Peter Gathercole Silver badge

Re: Linux?

Locked UEFI bootloader maybe?

Pull up the Windows 10 duvet and pretend Win8 and Vista were BAD DREAMS

Peter Gathercole Silver badge

Re: Hellooooo UBUNTU... @IsJustabloke

OK. You're right.

But eventually things have to change. Putting in a way to keep things enough the same to satisfy people like you (and me - I do echo your statement about just using it which is why I use Gnome Flashback), whilst allowing adventurous souls to move forward allows a stepping-stone migration of the sort that Windows 8 did not allow.

This was what I meant by choice.

But I wanted to point out that although Unity on Ubuntu looks like they were following the same approach as Microsoft (take the new interface or don't use Ubuntu), sanity prevailed, and a user can still choose something a little more familiar.

I have two family members for whom a new and different UI is completely inappropriate, but who have to stick with Windows because of software issues. One is my 85 year old father, who is comfortable with the WinXP/7 UI, and would find it too onerous to change (he would probably just stop using the computer), and the other is my wife, and I don't do anything to rock the boat there, for fear of the repercussions!

Peter Gathercole Silver badge

Re: Hellooooo UBUNTU...

It's possible to get something akin to the traditional Gnome 2 interface with the gnome flashback (previously called fallback) UI that is in the main repositories. It's not quite the old interface (it's actually a Gnome 2 UI built in Gnome 3).

And Cinnamon is in the Ubuntu repositories now.

And it is also perfectly possible to use Xubuntu (community Ubuntu distro) or Lubuntu mainstream release if you don't even want Unity installed.

This is what people wanted all the time. Choice. If Microsoft had provided the ability to select a 'traditional' desktop, maybe they would not have had too many people choosing it initially, but there would have been a slow conversion, and they would not have alienated their customer base.

Polish chap builds computer into a mouse

Peter Gathercole Silver badge


Make the mouse a Microwriter or CyKey as well, and you could cover all the bases.

A full computer with keyboard equivalent and mouse that you could hold and use in one hand. Need to work out some display that could be used while mobile. Maybe Glass or another HUD system.

'If you see a stylus, they BLEW it' – Steve Jobs. REMEMBER, Apple?

Peter Gathercole Silver badge


It's not 'passive', it just doesn't have a battery.

There is an inductive loop in the pen which picks up power from the tablet. I disassembled my daughters Graphire4 pen (the nib pressure sensor tends to stick if you leave it pressing on a surface for an extended time), and there's a significant board with chips on inside.

Peter Gathercole Silver badge

Re: Bundling other people's ideas again @sorry

You missed out a piece of technology. Google "Wacom", and particularly their product "Cintiq".

Graphic tablets and evolutions of them have never gone away. They've just been targeted at the people who really appreciate them, people like graphic designers and illustrators.

GRENADE! Project Zero pops pin on ANOTHER WINDOWS 0-DAY

Peter Gathercole Silver badge

Re: Google, the new Microsoft @Lost

Whilst true, that comparison is not fair to Google.

As pointed out in the article (and in several other places) Google do not have control over the deployment of new fixes to the core OS in the Android space. They may well publish a fix, and also issue new releases of Android that would technically work on a multitude of devices, but the devices are tweaked and locked by the manufacturer of the device, and sometimes by the service provider who ship the device, both of whom have no interest in allowing users to extend their use by installing patches.

I would love to see some legislation which mandated manufacturers and particularly service providers to free up boot loaders and other locking mechanisms a fixed time after their final update/patch is made available so they could take a generic release of Android. Maybe something from the reduction of waste legislation.

But it is difficult. Unfortunately, many Android devices have binary blobs, which are pieces of closed source code included in their Android release to handle communication, multimedia or other components in the device. There is nothing Google can do about this, short of changing the licensing model of Android. So even if the devices could take later versions of Android, unless the regression tested versions of the blobs are released (or open-sourced!), some devices will not take new releases of generic Android and remain fully functional.

Big Blue's biggest mainframe yet is the size of a fridge

Peter Gathercole Silver badge


Pretty much all racks have castors now, including supercomputers and mainframes.

I can check, but I think that all of the IBM P7 775 and z196 and the Cray XC40 frames that I can see in the machine room here have castors.

They also have wind-down feet and load-spreader bars when they are in their final position, so that they don't move.

Peter Gathercole Silver badge

Re: Many years ago...

A similar lift story from after I left IBM, but not as interesting.

We had a Power 4 system delivered in a T42 rack to a site I was working at in Poole, and to keep it under the weight limit for the lift and to get it through the doors (it was too high for the lift doors) we stripped the drawers out of the frame in the loading bay, tipped the frame on it's side, and then re-installed the drawers in the frame once it was on the machine room floor. All without telling the IBM hardware engineers!

The only problem we had was that the SPCN (Sequenced Power Control Network) cables were put back in the wrong locations, which gave us problems with the I/O drawer identification for the remaining life of the systems, even after they were connected correctly.

Peter Gathercole Silver badge

Re: So is it running z/OS or Linux or both? @boltar (again)

You got me thinking back more than 25 years to my training on Amdahl's Multiple Domain Facility (MDF) that I talked about in my last post, and I realised that back then, hypervisors did not really virtualise I/O.

What early hypervisors would do was to segregate memory and access to I/O channels (literally in the IBM mainframe world, but I suppose analogous to a set of disks or other devices hung off of a single adapter in more modern thinking), and provide a time-slice scheduler between partitions for the CPU.

All handling of I/O was performed natively by the hosted OS, including boot block requests, and it was only in very rare situations (such as extended I/O interrupts) that the hosted OS even knew it was running in a virtualised environment.

What this meant was that a hosted OS had to have complete and exclusive access to a string of disks, or indeed any other device, and all the hypervisor had to do was check that a hosted system did not try to access disks or other devices that were not presented to it.

The most difficult part of slicing a machine up like this was making sure that device interrupts were handled by the correct hosted OS, the one that had initiated the I/O operation.

There was virtualised addressing for each LPAR, so each hosted OS ran as if it has it's own contiguous address space starting at 0, and running up to the memory address configured. Additional protection was provided by memory having access keys attached to each page, and a hosted OS had to have the correct key to access a page, and each LPAR was only given it's own memory key. I think this memory keying was a hang-over from the early version of IBM VM, which did not have a fully virtualised addressing scheme.

It's only since you have shared virtualised I/O to the hosted OSs that hypervisors have become particularly sophisticated.

Peter Gathercole Silver badge

Re: So is it running z/OS or Linux or both? @boltar

Yes, that's quite true, but if you look at PR/SM, the IBM Power Hypervisor, or Amdahl's MDF (the bare-metal hypervisors I've had experience with), they are deliberately very limited in function. The name Hypervisor (derived from an old alternative name for an operating system, the Executive Supervisor) was coined to indicate that it was a supervising program that was not an operating system. It was very deliberate to not call the hosting environment an Operating System.

It's only relatively recently that you've had Type 2 or 'hosted' hypervisors that sit on top of what one would describe as a normal operating system like Linux or Windows. Examples include the original incarnation of VMware, Xen, KVM and Parallels. I understand that HP's Integrety VM sits on top of HP/UX, although I have no experience.

And then you have things like VMware ESXi, which is classed as a type 1 bare metal hypervisor, but is really a canned Linux stripped of all functions that are not required to host other systems. Mind you, you could probably say the same about IBM's Power Hypervisor, but that is so deeply embedded in the firmware of Power systems that it's relatively difficult to see that it is Linux at heart.

Complicating it still further are Oracle/Sun's containers and IBM WPARs, which are not true VMs but still allow you many of the advantages of partitioning.

It's all getting complicated.

Peter Gathercole Silver badge

Re: Many years ago... @Haro

Fortunately, the incidence of significant earthquakes in Basingstoke is very low.

Peter Gathercole Silver badge

Re: Many years ago...

I know the innards are probably different, but the 9125-F2C which from the picture looks like it uses the same frame, each frame when full weighs 3.5 tonnes.

The z13 won't weigh quite so much, but the racks themselves are pretty substantial.

Peter Gathercole Silver badge

Re: So is it running z/OS or Linux or both?

It should be noted that IBM pretty much invented virtualization with the 370 mainframe systems in the early 1970's. About the same time, Intel were making 4 bit microprocessors and TTL chips.

The virtualization will be performed either by the PR/SM type 1 (hardware) hypervisor or z/VM.

Read up on Type 1 hypervisors. There does not have to be a host OS, at least not as I think you understand them.

Peter Gathercole Silver badge

Many years ago...

... I planned the installation of a full height 9076 SP/2 into a normal office space in an IBM building in Basingstoke.

When installed, it was about half full, and did not quite exceed the floor loading weight.

After I left, I heard it had been filled. I had visions of it descending through the 11th floor, then the 10th, the 9th and on to the ground!

Peter Gathercole Silver badge

Re: Can I just have the case?

Probably, if you think you have the space.

This looks like the same racks that the 9125-F2C P7 775 system is packaged in (they're both products from IBM Poughkeepsie, NY), an if so, this is 2 racks side-by-side, with each rack over 2.10 metres tall and 1.8 metres deep. Both racks together would be around 2 metres wide.

In addition, they will not take standard 19" wide rackmount devices without some additional mounting hardware as the 'gap' is 26" IIRC (sorry, I realise I've mixed measurement units).

IBM actually have some quite fancy doors available for their standard T-series racks, if you want to pay for them!

Warning: Using encrypted email in Spain? Do not pass go, go directly to jail

Peter Gathercole Silver badge

Re: Get a grip...

What has always worried me is if you have a legitimate set of data in a form that is not recognised by security services, what's to stop them assuming (wrongly) that is is encrypted, and demand the non-existent key.

There is no key so it can't be provided, and in the UK that is enough for someone to be detained.

Judge spanks SCO in ancient ownership of Unix lawsuit

Peter Gathercole Silver badge

Re: Unixware

I was thinking more along the lines of buying the rights and open-sourcing it. Probably can't happen as SCOG never controlled the ownership of the rights, and I guess that Attachmate will allocate some value to them.

As I cut my teeth on Bell Labs. version/edition 6 and 7, BSD was never 'true' UNIX to me. And although it ultimately failed, the AT&T lawsuit against the Regents of the University of California over proprietary code meant that the current BSD releases are only really related to 'true' UNIX (what I tend to call Genetic UNIX) by old code (v7 and before) and some APIs.

The current BSDs cannot even use the term UNIX because (rightly or wrongly) that trademark has to be licensed and any OS wanting to use the term certified by the Open Group against a verification suite, one which *BSD* will probably fail.

In some senses, SunOS came back into the fold with SunOS 4.01 which refactored it's code base around SVR4.

Peter Gathercole Silver badge


I often wonder whether it would be possible to resurrect Unixware. This is the closest thing to a mainstream UNIX, and I would love to see a real genetic UNIX available again. But I think Linux has filled the gap where Unixware could exist.

Peter Gathercole Silver badge

Re: TSG is not SCO @Floke

Good summary.

I'm not sure about the Tarentella part though.

I thought (and Wikipedia appears to confirm this) that Tarentella was the remains of the original Santa Cruz Operation after they sold the UNIX server and services division to Caldera, and it was Caldera which renamed themselves The SCO Group.

Tarentella ended up being bought by Sun Microsystems, and is now a division of Oracle.

Darl McBride came into the picture, because he was the CEO of Caldera at the time Caldera bought the Santa Cruz UNIX assets. Before this, Caldera had been one of the early companies specialising in Linux distribution, which is why it was so ironic that they later started threatening to sue other Linux companies. Darl became the CEO of SCO Group when Caldera renamed itself.

Another piece of the picture is that I am sure that HP were originally involved with the original SCO in the transfer of assets from UNIX System Laboratories, when USL was wound up (I missed a bullet there, I was offered a job at USL as a Support/Consultant/Trainer in the UK in the early '90s). This is from memory, although I really ought to see whether there is a UniGram archive somewhere.

What will happen to the oil price? Look to the PC for clues

Peter Gathercole Silver badge

Re: Get hungry, not starve... @adam

You and tens or hundreds of thousands of other people.

In the event of a breakdown in cities, you need to get out fast, and with as many guns as possible to deprive the people already in the country, and to stop others following and taking what you took first!

There is a semi-rational a reason why US isolationists build defendable enclosures.

This $10 phone charger will wirelessly keylog your boss

Peter Gathercole Silver badge

IBM keyboard

Just converted my youngest son to the merits of IBM buckling spring technology (I graciously allowed him to use my 1990 built Model M for a few weeks).

Bought him a Unicomp USB 'IBM Classic' keyboard for Christmas.

They're still about as heavy as the originals.

It's 4K-ing big right now, but it's NOT going to save TV

Peter Gathercole Silver badge

Re: Meh. Build it and they will eventually come. @Dave

I obviously look at this differently from many of the people here, although I don't believe that the OP was stating anything about why he purchased the Sony or the size of the TV he purchased. I presumed he did it because of the failure of his previous one, bearing in mind he did not want any of the shiny features.

I buy primarily on price. At the moment, if I were in the market for one, I would prefer to buy a £250 1080p TV now, and another one (probably better) in a couple of years should I feel the need (read on), rather than a £500+ one with a five year guarantee now.

I can see that there is a difference in quality, but not one that I feel is worth the extra money . And quite often, the cheaper ones can be 'life extended' by capacitor replacement or board-swap maintenance. My current TV (a Digihome bought from Tesco, in case you wanted to know) is seven years old, and has had a power supply capacitor replacement and a t-con board at a total additional cost of about £20 plus a little of my time. It lasted the best part of four years without any work, and I can see it lasting another couple of years, although it may be relegated to another room at some time.

Maybe I've been lucky. I feel the picture on this one is good enough, although the blacks could be blacker. The upscaler on non-HD content is good, and I do not suffer from block decoding artefacts or noticible high-speed smear, although I will admit that the best quality signal it gets fed is from a 3rd generation Sky HD box. I've certainly seen some stinkers (I also have a similar aged 32" Sanyo TV bough second hand for the kids game consoles, which is pretty bad).

But what I have is 'good enough'. I've seen many big name (but not necessarily THE big names in TVs) that are no better, and were much more expensive than my current TV. I'll certainly not be buying a TV for more than about £350 absolute maximum any time soon, and I suspect that there is a huge segment of the buying public who will think the same.

Peter Gathercole Silver badge

Re: Meh. Build it and they will eventually come.

In what world are 'smart tvs' the only ones available, especially 2 years ago?

I suspect that you had limited your choice by brand and how much you wanted to spend, but I can assure you that even now, full HD 'dumb' TVs are still available, some from major brands, and many quite good quality ones from volume or badge engineered brands that techno-snobs tend to ignore.

Boybanders ONE DIRECTION launch DoS attack on open-source bods

Peter Gathercole Silver badge

Re: I read as far as "Boybanders"

Maybe not. Maybe the author has not realised that One Dimension Direction (I'm sorry, that's how I read 1D, which they use as an abbreviation) are all now over 20, and have pretty much shed their 'boy band' image (they're often seen sporting stubble and other 'adult' stylings).

Mind you, Take That are still occasionally called a 'boy band' even though they are all over 40.

MI5 boss: We NEED to break securo-tech, get 'assistance' from data-slurp firms

Peter Gathercole Silver badge

Whilst I completely agree with what you say, isn't it the case that he is saying "See, we can prove that they are using the Internet from these cases. Now give us the facilities and powers to snoop so that we can see this while it is happening, rather than after the fact".

NHS refused to pull 'unfit for purpose' Care.data leaflet

Peter Gathercole Silver badge

"it is already based on statistical assumptions" @AC

Yes. Broad statistical assumptions, but risk is still shared, and insurance companies are unlikely to deny cover except in very specific cases.

But being able to mine exact information about individuals allows them to say "I would not touch this guy with a barge pole", whereas previously, they would have had to have taken effectively a gamble on whether the whole demographic they were in was a risk.

What happens at the moment is that if someone is in a particular risk group, they will probably be offered more expensive insurance, whereas if the insurer had specific information (which may not actually have been told to the patient as it may be detailed clinical information), they could turn round on an individual-by-individual basis and just say no.

And I would hazard to suggest that they would not say why an individual had been refused because of 'data protection' issues.

The whole concept of insurance is shared risk. If the insurance companies were able to decide to only offer insurance on things that they knew were unlikely to happen (the flip side of refusing to insure for things that they could tell were more likely to happen because of detailed individual information), then there is no real risk, and they would just take the money and laugh!

Double-digit tablet growth spurt is OVER, say pundits

Peter Gathercole Silver badge

"The collapse of the tablet market in 2014 was alarming"

Funny, I would have thought that a "collapse" would indicate a decline in the numbers sold. But no! they're still increasing, just not as fast.

What this indicated is that marketing bods expect too much, and do not understand their markets. No sales market can grow forever, and even if the devices only lasted a year, you would get to a point where sales were stable and never increased. As it is, most tablets last more than a year (mine is nearly three years old and still doing what I need it to do), so the market will saturate, at which point you just get replacement sales.

It's the same as the TV manufacturers thinking that the bump in sales due to replacement of CRT TVs by flat panel ones would go on forever.

Elite:Dangerous goes TITSUP

Peter Gathercole Silver badge

Re: I've been thinking about playing.... @Blinky

My favourite on the BBC version with analogue joysticks (or even a Bitstick, which was even better) was to move onto the axis of rotation, match the rotation rate, and accelerate at maximum. Provided that you were aligned correctly, it did not appear to matter what speed you were travelling at. Was a lot faster that waiting for the docking computer to faff around, which often gave you an opportunity to go and make a cup of tea in the time it took to dock.

And it wasn't perfect! When I did use the docking computer, I still had the occasional crash. Was most distressing to come back from making tea to find a game over message.

Edu-apps may be STALKING YOUR KIDS, feds warn

Peter Gathercole Silver badge

Re: Where the buck stops

"Perhaps ALL TV channels should be required to show public information ads about internet and App security".

That's not a bad idea. Especially the channels specifically provided for children.

You could also make it age sensitive, as there is a clear difference between channels provided for pre-school, pre-teen and teenage markets.

Run them as public information films, like they used to for road safety or stranger danger.

Just don't blame Bono! Apple iTunes music sales PLUMMET

Peter Gathercole Silver badge

Re: Bah! @Stevie

Were you reading my music catalogue!

UK air traffic bods deny they 'skimped' on IT investment after server mega-fail

Peter Gathercole Silver badge

Re: It was said to be a line of code with a previously unfound error

This is exactly why they have strict operating procedures that dictate that if they can't get the system back up within a set period of time, the invoke their contingency plans to keep passengers, aircraf and aircrew safe.

I understand from an interview I heard on BBC Radio 4 on Friday or maybe Monday that this threshold is 7 minutes. The interviewee said that they had the system running again after 15 minutes, but that was 8 minutes too late.

Once they've initiated the contingency plan, which basically involves preventing any more aircraft from entering the controlled air space and getting as many that were already there on the ground as quickly and safely as possible, the damage was done. It was inevitable that there would be issues that ran on into the following days (aircraft and aircrew being in the wrong place, aircraft missing their scheduled maintenance because they were not at their maintenance location etc.)

Webcam-snooping spawn of ZeuS hits 150 banks worldwide

Peter Gathercole Silver badge

Re: Some day

I was going to say something very similar.

I was worried about my Father until I read this. He does not have Word, and although I cannot be complacent about this (other vectors are still possible), the fact that the major one appears to be Word actually makes me breathe a little more easily. Must check his AV status though.

If it had been using the CORBA vulnerability that was publicised a few weeks back, I may have had more concern.

VISC-y business: Can Soft Machines keep the free lunch counter open?

Peter Gathercole Silver badge

Re: Writing parallel code doesn't have to be any harder than writing sequential code.

The difficulties lie in accessing the data structures, and also in efficient memory utilisation.

If you have a single stream of code execution, the processor itself causes an implied serialisation of access to data structures. Once you get more than one processor running, you then have to worry about making sure that two or more threads running simultaneously do not try to write to the same data structure.

You end up having to deal with spinlocks and other mechanisms that are completely unnecessary with single processor code execution. It's been this way ever since multiprocessor machines were available, and I worked on my first multiprocessor machine back in 1987. This challenge gets exponentially worse as the number of cores goes up. There are ways of managing this by separating the data into per-thread memory pools, but again it's something you just don't have to think about with single core machines.

The classic way of doing this has been to put an implied separation into the work that the system is doing. Things like not having multi-threaded processes so that there is no data contention at a process level, or, like the example you quote, having a state machine serialising access to common data structures. But when you start talking about true parallelisation, with multiple threads working on the same data set, these approaches don't work. HPC code writers have struggled with this problem for many years.

You also have the problem that modern multiprocessor machines are normally NUMA, which means that in order to get the best out of the machine, you have to have some idea of how to align memory to the CPUs executing the threads using the bulk of the data.

Both of these problems get much worse if you don't have any idea of the shape of the machine at the time you are writing the code.

What I read this approach as doing is to abstract the machine topology away from the hardware, and putting the complex parallelisation into the abstraction layer. If done correctly, this would allow the code writers to write for a single virtual machine shape without having to worry about the underlying hardware, much in the same way that a JVM allows writers to write code that appears processor neutral.

El Reg Redesign - leave your comment here.

Peter Gathercole Silver badge

Re: PROPER Time Stamps!!!

I want proper time stamps so that I can reply specifically to one comment in a comment trail, and have everybody know exactly to what I was referring. It's not enough to use the posters name or the title, because we get into conversations with each other on the threads, keeping the comment the same.

Relative timestamps are no bloody use at all!

Car-crash IT: HUGE write-off for Universal Credit - PAC

Peter Gathercole Silver badge

Re: Pretty good @AC re Entitled?

You would have to make it £100 per person in the household, including the children, if you wanted to make a flat-rate minimum guarantee.

And that would have it's own problems as people realised that the more kids they had, the more money they would receive.

If you were to make the benefits system back to one where need was not taken into account, then you would have to be prepared to return to the days of the flop house, workhouses and foundling orphanages, people living on the streets and escalating crime and prostitution as people did whatever was necessary to survive.

The whole point of benefits where they are needed is to provide a way of living (note I do not say that it should be particularly comfortable) for whole family units, not just individuals. And benefits where needed requires systems to assess the need.

It was a real eye opener when the historical TV programme "Turn Back Time" reminded me that in the first half of the 20th Century in England, people were forced to sell any possessions of value before they would be given any state support if they could not support themselves.

Blu-ray region locks popped by hardware hacker

Peter Gathercole Silver badge

Re: Region Locks @Vladimir

I see your point, but this is just how publishing rights have ever worked, be they for films, books magazines or music. It's been that way ever since works were re-produced and distributed locally. A publisher or distributor buys the rights from the copyright holder. Just look at how books and CDs are published by different publishers on each side of the Atlantic. The only difference is with DVDs and BluRays there is a technical way to enforce it. It may look like a cartel, but unfortunately it's enshrined in well established law.

Until we get a completely global market with no trade barriers, common taxation and the same price, adjusted by whatever exchange rate is current, there will always have to be differentiation of the market in different regions. There may also be classification issues as well for some controversial material.

If you do not give regional rights to distribute these things, then it means that you could only use a distribution company that was global, otherwise some regions would have no distribution at all. If that were the case, you would really find completely different prices depending on how much it cost to import the work from the producing country.

To change it would require huge amendments to copyright legislation and world trade agreements in general. You might wish it changed, but that does not mean that it is going to happen.

Peter Gathercole Silver badge

Re: Region Locks

The reason is not just price differentiation. It's also that different countries/regions have distribution deals with different companies. So the region lock supports a company which has bought distribution rights for a film in their region to protect their investment from imports from outside the region by a different company that has no rights there.

If a film has different release dates in different regions/countries, it also protects the rights of the distributor in the country that releases the film later or last.

I admit it's all still pretty arbitrary and possibly petty from a consumer's position, but not from the distribution company's point of view.

Peter Gathercole Silver badge

Re: Forced to view content (Adverts etc.)

What amuses me is Disney FastPlay on DVDs.

They spend 15 seconds explaining that you will be advertised to, and then play about 4-5 minutes of adverts before the move automatically starts. This is supposed to be playing faster?

The alternative is jumping to the top menu and selecting "Play Feature". OK, it's more button presses, but a whole lot faster than the default.

The Great Unwatched: BBC hails glorious digital future for Three

Peter Gathercole Silver badge

BBC Choice

That was the original name of what became BBC3. It used to show time-shifted repeats of the best of the other BBC channels, except when Glastonbury was on when it was pretty much full time coverage.

So, having BBC1+1 is almost like going back to it's roots.

And remember, significant numbers of people who were early smart TV and BluRay player adopters have recently been deprived of iPlayer when the BEEB decided to re-work the UI to make it incompatible with older devices.

EU law bods: New eCall crash system WON'T TRACK YOU. Really

Peter Gathercole Silver badge

Re: Track Me @ ElNumbre

Yes, you need to attend paranoia classes.

The type that teaches you to be more paranoid.

Feast your eyes: 10 'fortysomething' smart TVs

Peter Gathercole Silver badge

Re: model-specific and poorly maintained as models age

Yes, you have to be careful about putting all your eggs into one basket.

I was recently very annoyed to see iPlayer disappear from 2 Sony 'Smart' Bluray players that I have. Apparently, the BBC changed the way iPlayer worked (they removed what was termed the "Big Screen" format) in a way that was incompatible with some devices made before 2012, and Sony are not intending to supply an upgrade to these devices. Now 2012 is no more than three years ago, however you look at it, so that's not a very long life for a consumer device.

As it turns out, I bought these Bluray players mainly for their iPlayer function (it was before NowTV or Roku devices were around at a low price), and I've never played a Bluray disk (although they are used to play DVDs), so I am none too pleased with both the BBC and Sony.

But at least I can replace these players relatively inexpensively, especially if I get a £10 Now TV box. If I had lost the function from the telly itself, I might have been even more annoyed.

Boffins unearth the ultimate antique art - 500,000 years old

Peter Gathercole Silver badge

Re: "If you don't know the intention of the person who made it, it's impossible to call it art,"

No, no.

It's the earliest example of ridiculous warnings. It actually says "May contain fish"

Stop the IoT revolution! We need to figure out packet sizes first

Peter Gathercole Silver badge

Re: Excited about Internet-of-stuff?

There's a fix to the batteries running down in the remote. You put a mains powered 'controller' with a simple on/off toggle setting to override the remote in a fixed position in the room, somewhere like on the wall at shoulder height just inside the door.

Hey presto, problem fixed.

.... I feel I'm missing something here.

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