In brief, if you want Varnish to keep a 8GB HTTP cache, then it's going to malloc() 8GB. It expects the kernel to manage swapping whatever parts of that are unused. He points out that in an app such as Squid, which tries to maintain its own disk cache alongside its RAM cache, the two swap algorithms fight each other in a very counter-productive way.
I think all developers ought to be free to take that same approach. Why should an application programmer write potentially substandard memory management routines when the OS is supposed to be good at it. I agree there will be outliers where the application has special domain knowledge that it can use to manage memory more effectively than the kernel. I suspect there are *very* few such cases.
What if the programs don't "play nice" and refuse to release their RAM when it's needed? (i.e. Internet Explorer is storing a bunch of images you downloaded two days ago, and refuses to erase them from cache.) Wouldn't that force the OS to do HDD thrashing?
Only if the program in question also insists on *reading* that chunk of memory. Otherwise, it gets swapped to disk, then just stays there, never getting swapped back to RAM. No harm done, except that a small amount of HDD goes to waste until the next reboot.
So it's more than an extra $200, because you've got her a Macbook with a bigger screen.
But the iPad's screen is smaller than 10". So we've still not found someone for whom an iPad is a good fit.
UNLESS we're talking about having an iPad *and* a Macbook, in which case we're talking about spending $500 or more on something that duplicates functionality you already have.
That's exactly how it works. Fine by me. You can mute an individual buzz, or you can opt out of having it in your Gmail interface altogether. So what are you complaining about?
Is the word 'bloody' really worthy of ***'ing out? I'm a dumb American, so I really don't know. I always figured it was kind of equivalent to 'darn' here in the States.
No, it's not worth ****ing out. It can be construed as blasphemous, as it's derived from "by our lady". But you can say it on daytime TV, so you can certainly type it on Slashdot.
I think where we're at cross purposes is that you're talking about people ditching their laptop/desktop. ("most people have that one little program that they would never give up").
I'm thinking more about people getting their first computer. (Yes, there are people who don't already have one).
I think WiFi will become pretty much ubiquitous in consumer level printers over the next few years.
If you want to write for any amount of time you are at your desk where you might as well use a full sized keyboard and the computer that will print without hunting for an adapter.
If you already own such a computer, then yes. But if you don't, it's another $400 spend (much more if it's Apple). Or sit at your desk with your tablet in its keyboard caddy stand.
Yeah, if money (and space) was no object, you'd have both. But how good is "good enough" that it's not worth getting a "real" computer too.
With the iPad, I don't know. I guess it depends on the 3rd party software that comes out for it. I think you probably don't need your calendar app or ebook-reading app to continue running in the background when you aren't using them.
On reflection, I think it depends on how fast the suspend/resume is. If I can switch between apps as quickly as if they were running simultaneously, then I'm happy.
It would also be nice if certain apps could get a special dispensation to multitask, maybe at the cost of some extra consideration by the App Store vetting team. It could be designed to allow one music app to run it the background at any one time, for example, meaning you could listen to Spotify/Pandora/Last.fm.
Palm did. You can easily go into card view and see what apps are running*... wanna close, "throw" it toward the top of the screen. It may not be instantly intuitive, but once it's explained to you (what you see here are running apps... here's how you close one) it's really easy to remember and do.
I'm waiting to find out whether the iPad will function without a "real" computer to sync to. If it does, I absolutely think there's a huge demographic who would be able to use it as their only computer.
These people use their home computers for the Web and email, for very simple word processing and maybe for the ambitious, spreadsheets for home accounts and hobbies.
I don't think there's anything to stop them using an iPad for all that, especially with the keyboard addon. Just how 'watered down' the office suite is, we've yet to see. I don't see why it couldn't be as full featured as, say, Word 6. The stuff they'd leave out would be for ease-of-use reasons.
Typical home use that might stretch the iPad:
Digital photos. I think it will probably be a pretty strong platform for importing photos from cameras, sorting and categorising. The problem is storage. But external storage can fix that -- either some sort of NAS appliance, or perhaps even an online service. It wouldn't surprise me if Apple eventually encourages a home computing setup of Airport + iPad + Time Capsule. With a suitably clever system deciding what to keep on the iPad and what to archive to the Time Capsule, it could be pretty slick.
Getting more niche: home video. I'd be interested to know to what extent these things could handle simple video editing. I mean, my phone can film and playback video. A simple video editor that doesn't do too many fancy effects might be achievable. Touchscreen would be a real boon here. Same storage concerns as for photos, only more.
So yeah, I think a lot of people could potentially use an iPad as their only computer. And that terrifies me, because it's going to be such a closed system.
Of course Apple doesn't want to completely kill the market for Macs. I fully expect to see an iLife for iPad, that's just full of little hints that you could do more on a real Mac. (Just as something keeps niggling me I should jump from GarageBand to Logic... with the attendant hardware upgrade required...)
What if you could view the document and the browser and never switch between apps?
There are plenty of ways to get around the need to multitask.
Let's get this clear. We're not really talking about multitasking in the CS sense. Obviously the kernel can do multitasking. We're talking about the device allowing us to conveniently use more than one app at more or less the same time.
Any sufficiently advanced workaround - such as instantaneous state saves, in many cases - is indistinguishable from multitasking. If you're telling me that's what it has, then fine.
I don't think that apps having an embedded web browser is an acceptably flexible workaround. Just because my example was a word processor and a browser doesn't mean that's the only case. There's likely to be just as valid a case for wanting to switch between arbitrary third party app A and arbitrary third party app B.
Oh, and even if there is, you can be SURE that Apple will never REMOVE (and secretly, too!) books from your iPad, UNLIKE SOME 'bookstores'.
How on earth can you be 'SURE' of that?
I suppose it's unlikely that Apple would put themselves in that position, because providing a self-publishing platform like Amazon's Digital Text Platform isn't really Apple's style.
Amazon found themselves in a tricky situation. Due to a DTP user who'd (knowingly or unknowingly) published material that was neither licensed nor PD, they had sold a load of copies of 1984 that they weren't entitled to sell. They handled this badly. But, pretty quickly, they apologised, said it would never happen again, and gave every affected user a legitimate copy of 1984.
Having made a mistake, they cleared it up in an exemplary fashion.
What is the bl**dy obsession with whether it multitasks or not?
Forgive me if I've misunderstanding what "not multitasking" means in the context of the iPad. I'm assuming it means that switching from one app to another means completely closing app 1, then opening app2.
So, let's say I'm reading a book. Maybe Paul Auster's City of Glass, in which part of the story focuses on the shapes a man traces out walking the streets of New York City. I'm curious about the exact streets, so I want to flick to the mapping app (or a browser), to see what part of Manhattan he's talking about, and how it's actually laid out. Do I really need to note down the streets to look up, close down the book reader, open the map app, browse the maps, close the maps app, return to the reader app?
(I had exactly this scenario earlier this week, except it was a paper book, and I looked up the maps in a paper Lonely Planet guide to NYC)
There are plenty of use cases like this. Apple is publishing iWork for the iPad. How often do you control-tab between a word processor and a browser? I do it often.
Trying to get into the designers' heads, I think there's a couple of reasons for the inability to multitask apps.
1. Performance. Not so much that the hardware is underpowered, but that they're committed to a very slick, responsive UI experience (what I gather Mac people call "teh snappy"), which they don't want to jeopardise no matter what. I gather iPad's browser is awash with cosmetic stuff that makes browsing feel tactile. A little jitter while scrolling or scaling would spoil that. They don't want another app to steal cycles and spoil that.
Of course, a smart scheduler could orchestrate things so that the foreground application got everything it needed. I expect this in a future revision.
2. UI. Simply, that they've not come up with a completely idiot-proof user interface, such that knuckle-draggers understand the difference between closing an app and backgrounding it.
I'm going to posit that the success of the iPod, which was not instantaneous, is really tied to the Apple store and their ability to deliver songs,
I don't think that's the main factor. There were already MP3 players on the market, but the iPod was the first one where the UI hadn't been cobbled together by a team of engineers with no interest in usability or polish.
Neither iPod nor iTunes is perfect, by a long way. But until iPod came along, using an MP3 player was like setting a digital watch or a VCR in 1983.
The iPhone delivered more functionality than the other phone manufacturers were willing to dole out to us
Other phones had the functionality, after a fashion -- email, browsers, calendar, address book, and the ability to run 3rd party apps. But again, the UI was usually terrible. Even on Nokias, who were among the better companies, it would seem as if completely different teams had written different parts of the UI, with no look and feel guidelines to keep them on the same page.
The iPhone was actually designed to be a pleasure to use. (Other decent phones arrived around the same time, e.g. from Blackberry).
But I agree with your main thrust - I don't see that the iPad has any of the magic pixie dust that iPod or iPhone had.
But I think that by the 3rd gen, it'll be a success. It's a solution looking for a problem, but someone will identify that problem and there'll be "an app for that" soon enough.
Not everywhere. But there are certainly applications where keyboards aren't required, or where onscreen keyboards are good enough.
People are happy with their touchscreen phones. The self-service checkout at my local supermarket uses only a touchscreen (and a barcode scanner!).
The question is more, for the kinds of thing you want to do on an iPad, is the smaller form factor worth the sacrifice of a keyboard?
Even doing standard Web stuff - filling in forms for web shops, emailing, posting on forums, I do a lot of typing. I'll be surprised and impressed if the iPad onscreen keyboard doesn't get in the way.
Slashdot Mirror
Here's the confusion.
You think "HDD caching" means "moving stuff from RAM to HDD".
GP thinks "HDD caching" means "keeping a cache in RAM of stuff who's 'official' home is on the filesystem".
GP is using the more [ahem] conventional meaning.
You caused a lot of confusion by saying "HDD caching" when you meant "virtual memory" or "paging".
Here's a good writeup from a developer who definitely expects you to be using swap:
http://varnish-cache.org/wiki/ArchitectNotes
In brief, if you want Varnish to keep a 8GB HTTP cache, then it's going to malloc() 8GB. It expects the kernel to manage swapping whatever parts of that are unused.
He points out that in an app such as Squid, which tries to maintain its own disk cache alongside its RAM cache, the two swap algorithms fight each other in a very counter-productive way.
I think all developers ought to be free to take that same approach. Why should an application programmer write potentially substandard memory management routines when the OS is supposed to be good at it. I agree there will be outliers where the application has special domain knowledge that it can use to manage memory more effectively than the kernel. I suspect there are *very* few such cases.
What if the programs don't "play nice" and refuse to release their RAM when it's needed? (i.e. Internet Explorer is storing a bunch of images you downloaded two days ago, and refuses to erase them from cache.) Wouldn't that force the OS to do HDD thrashing?
Only if the program in question also insists on *reading* that chunk of memory.
Otherwise, it gets swapped to disk, then just stays there, never getting swapped back to RAM. No harm done, except that a small amount of HDD goes to waste until the next reboot.
The only system where it makes sense to disable swap space is a system with no HDD at all.
Or an OS with terrible swap algorithms.
Anecdotal, subjective and unscientific: I perceived an improvement in performance when I disabled swap in XP.
Yes. I have a similar problem when people running servers complain that the CPU is at 100%.
If you're seeing an actual slowdown in performance, fine, worry about it.
Otherwise, 100% CPU usage is a good thing: it means there's a process that's not IO bound.
So it's more than an extra $200, because you've got her a Macbook with a bigger screen.
But the iPad's screen is smaller than 10". So we've still not found someone for whom an iPad is a good fit.
UNLESS we're talking about having an iPad *and* a Macbook, in which case we're talking about spending $500 or more on something that duplicates functionality you already have.
It was the $200 worth of 'Pro' that I was wondering about.
I believe all iPhone applications will work on the iPad. http://www.apple.com/ipad/app-store/
They'll be quite the second-class experience though - either blocky from pixel-doubling, or a little rectangle in the middle of a black screen.
That's exactly how it works. Fine by me. You can mute an individual buzz, or you can opt out of having it in your Gmail interface altogether. So what are you complaining about?
It doesn't matter how many followers you have if you never post anything on Buzz.
Is the word 'bloody' really worthy of ***'ing out? I'm a dumb American, so I really don't know. I always figured it was kind of equivalent to 'darn' here in the States.
No, it's not worth ****ing out.
It can be construed as blasphemous, as it's derived from "by our lady". But you can say it on daytime TV, so you can certainly type it on Slashdot.
Double post, sorry...
I think where we're at cross purposes is that you're talking about people ditching their laptop/desktop. ("most people have that one little program that they would never give up").
I'm thinking more about people getting their first computer. (Yes, there are people who don't already have one).
I think WiFi will become pretty much ubiquitous in consumer level printers over the next few years.
If you want to write for any amount of time you are at your desk where you might as well use a full sized keyboard and the computer that will print without hunting for an adapter.
If you already own such a computer, then yes. But if you don't, it's another $400 spend (much more if it's Apple). Or sit at your desk with your tablet in its keyboard caddy stand.
Yeah, if money (and space) was no object, you'd have both. But how good is "good enough" that it's not worth getting a "real" computer too.
With the iPad, I don't know. I guess it depends on the 3rd party software that comes out for it. I think you probably don't need your calendar app or ebook-reading app to continue running in the background when you aren't using them.
On reflection, I think it depends on how fast the suspend/resume is. If I can switch between apps as quickly as if they were running simultaneously, then I'm happy.
It would also be nice if certain apps could get a special dispensation to multitask, maybe at the cost of some extra consideration by the App Store vetting team. It could be designed to allow one music app to run it the background at any one time, for example, meaning you could listen to Spotify/Pandora/Last.fm.
Palm did. You can easily go into card view and see what apps are running*... wanna close, "throw" it toward the top of the screen. It may not be instantly intuitive, but once it's explained to you (what you see here are running apps... here's how you close one) it's really easy to remember and do.
Mmm, but remember: knuckle draggers.
You can pretty much guarantee that will be possible.
It's not that it can't multitask. It's that there's a deliberate restriction on which apps can do so.
I'm waiting to find out whether the iPad will function without a "real" computer to sync to. If it does, I absolutely think there's a huge demographic who would be able to use it as their only computer.
These people use their home computers for the Web and email, for very simple word processing and maybe for the ambitious, spreadsheets for home accounts and hobbies.
I don't think there's anything to stop them using an iPad for all that, especially with the keyboard addon. Just how 'watered down' the office suite is, we've yet to see. I don't see why it couldn't be as full featured as, say, Word 6. The stuff they'd leave out would be for ease-of-use reasons.
Typical home use that might stretch the iPad:
Digital photos. I think it will probably be a pretty strong platform for importing photos from cameras, sorting and categorising. The problem is storage. But external storage can fix that -- either some sort of NAS appliance, or perhaps even an online service. It wouldn't surprise me if Apple eventually encourages a home computing setup of Airport + iPad + Time Capsule. With a suitably clever system deciding what to keep on the iPad and what to archive to the Time Capsule, it could be pretty slick.
Getting more niche: home video. I'd be interested to know to what extent these things could handle simple video editing. I mean, my phone can film and playback video. A simple video editor that doesn't do too many fancy effects might be achievable. Touchscreen would be a real boon here. Same storage concerns as for photos, only more.
So yeah, I think a lot of people could potentially use an iPad as their only computer. And that terrifies me, because it's going to be such a closed system.
Of course Apple doesn't want to completely kill the market for Macs. I fully expect to see an iLife for iPad, that's just full of little hints that you could do more on a real Mac. (Just as something keeps niggling me I should jump from GarageBand to Logic... with the attendant hardware upgrade required...)
My wife. Who takes her MacBook Pro from the kitchen to the living room and back again.
[...]
Has no use for a 'real' computer.
So why does she have a MacBook Pro?
What if you could view the document and the browser and never switch between apps?
There are plenty of ways to get around the need to multitask.
Let's get this clear. We're not really talking about multitasking in the CS sense. Obviously the kernel can do multitasking. We're talking about the device allowing us to conveniently use more than one app at more or less the same time.
Any sufficiently advanced workaround - such as instantaneous state saves, in many cases - is indistinguishable from multitasking. If you're telling me that's what it has, then fine.
I don't think that apps having an embedded web browser is an acceptably flexible workaround. Just because my example was a word processor and a browser doesn't mean that's the only case. There's likely to be just as valid a case for wanting to switch between arbitrary third party app A and arbitrary third party app B.
Oh, and even if there is, you can be SURE that Apple will never REMOVE (and secretly, too!) books from your iPad, UNLIKE SOME 'bookstores'.
How on earth can you be 'SURE' of that?
I suppose it's unlikely that Apple would put themselves in that position, because providing a self-publishing platform like Amazon's Digital Text Platform isn't really Apple's style.
Amazon found themselves in a tricky situation. Due to a DTP user who'd (knowingly or unknowingly) published material that was neither licensed nor PD, they had sold a load of copies of 1984 that they weren't entitled to sell. They handled this badly. But, pretty quickly, they apologised, said it would never happen again, and gave every affected user a legitimate copy of 1984.
Having made a mistake, they cleared it up in an exemplary fashion.
You're saying Apple would never make a mistake?
What is the bl**dy obsession with whether it multitasks or not?
Forgive me if I've misunderstanding what "not multitasking" means in the context of the iPad. I'm assuming it means that switching from one app to another means completely closing app 1, then opening app2.
So, let's say I'm reading a book. Maybe Paul Auster's City of Glass, in which part of the story focuses on the shapes a man traces out walking the streets of New York City. I'm curious about the exact streets, so I want to flick to the mapping app (or a browser), to see what part of Manhattan he's talking about, and how it's actually laid out. Do I really need to note down the streets to look up, close down the book reader, open the map app, browse the maps, close the maps app, return to the reader app?
(I had exactly this scenario earlier this week, except it was a paper book, and I looked up the maps in a paper Lonely Planet guide to NYC)
There are plenty of use cases like this. Apple is publishing iWork for the iPad. How often do you control-tab between a word processor and a browser? I do it often.
So, just how much can a device do, without being a computer.
The iPad has a full featured Web browser (unless the absence of Flash bothers you). An office suite will be available.
Where's the line that says "Here's what you need to be able to do in order to be a computer" - and does that line move?
Seems to me that the iPad does everything a computer does, but only if Apple lets it.
Trying to get into the designers' heads, I think there's a couple of reasons for the inability to multitask apps.
1. Performance. Not so much that the hardware is underpowered, but that they're committed to a very slick, responsive UI experience (what I gather Mac people call "teh snappy"), which they don't want to jeopardise no matter what. I gather iPad's browser is awash with cosmetic stuff that makes browsing feel tactile. A little jitter while scrolling or scaling would spoil that. They don't want another app to steal cycles and spoil that.
Of course, a smart scheduler could orchestrate things so that the foreground application got everything it needed. I expect this in a future revision.
2. UI. Simply, that they've not come up with a completely idiot-proof user interface, such that knuckle-draggers understand the difference between closing an app and backgrounding it.
I'm going to posit that the success of the iPod, which was not instantaneous, is really tied to the Apple store and their ability to deliver songs,
I don't think that's the main factor. There were already MP3 players on the market, but the iPod was the first one where the UI hadn't been cobbled together by a team of engineers with no interest in usability or polish.
Neither iPod nor iTunes is perfect, by a long way. But until iPod came along, using an MP3 player was like setting a digital watch or a VCR in 1983.
The iPhone delivered more functionality than the other phone manufacturers were willing to dole out to us
Other phones had the functionality, after a fashion -- email, browsers, calendar, address book, and the ability to run 3rd party apps. But again, the UI was usually terrible. Even on Nokias, who were among the better companies, it would seem as if completely different teams had written different parts of the UI, with no look and feel guidelines to keep them on the same page.
The iPhone was actually designed to be a pleasure to use. (Other decent phones arrived around the same time, e.g. from Blackberry).
But I agree with your main thrust - I don't see that the iPad has any of the magic pixie dust that iPod or iPhone had.
But I think that by the 3rd gen, it'll be a success. It's a solution looking for a problem, but someone will identify that problem and there'll be "an app for that" soon enough.
Touch screens will never replace keyboards.
Not everywhere. But there are certainly applications where keyboards aren't required, or where onscreen keyboards are good enough.
People are happy with their touchscreen phones. The self-service checkout at my local supermarket uses only a touchscreen (and a barcode scanner!).
The question is more, for the kinds of thing you want to do on an iPad, is the smaller form factor worth the sacrifice of a keyboard?
Even doing standard Web stuff - filling in forms for web shops, emailing, posting on forums, I do a lot of typing. I'll be surprised and impressed if the iPad onscreen keyboard doesn't get in the way.