10 Things that "Absolutely suck" about the iPhone. (Yes I have one)

[cmaier]

Mike - you said you had it down to 1MB free? Was that with the ipod function running in the background? seems the easiest way to pile on a little extra memory usage in a parallel process.

 

[Mike Overbo]

(BTW - I'm assuming those other tabs really load off the net again, and you aren't just seeing them re-render?)

I'm sure enough; If they weren't loading off the net, I wouldn't be seeing wi-fi activity.

 

[cmaier]

Can you try top with this:

http://www.tictacwhoa.com/mem.html

In theory it allocates 256MB. (It runs, but not sure it's actually giving me 256MB).

 

[Mike Overbo]

Can you try top with this:

http://www.tictacwhoa.com/mem.html

In theory it allocates 256MB. (It runs, but not sure it's actually giving me 256MB).

Array size: 256000000 9. Based from what I see in top, it doesn't actually allocate memory.

 

[zbop#IM]

Just curious what are you guys trying to prove?

It seems like there is a fair amount of mixup here in regards to demand-paging vs. page swapping vs. swap reservation vs. vs. file system page cache. Although they are all aspects of VM, the terms and assumptions are flying fast and loose

 

[cmaier]

We're simply trying to determine if iphone implements vm. We've found hints of it, but at this point we're trying to create a working set larger than physical memory to see what happens.

 

[zbop#IM]

We're simply trying to determine if iphone implements vm. We've found hints of it, but at this point we're trying to create a working set larger than physical memory to see what happens.

Well, I don't know anything about OSX or the iphone version of OSX, but based on the previous posts it seems like it implements demand-paging, not sure about page swapping.

Testing this indirectly such as browsing or loading a video probably isn't going to tell you anything.

Note, that if you implement any code to test this, you should at least write-fault all the pages in that region rather than just allocate. On most VM systems, allocation only results in a reservation against swap or reservation against memory depending on the OS and configuration. And if you just read-fault the pages, it may allocate-on-demand but free them as needed, which isn't a valid test.

Good luck

 

[cmaier]

Somewhere back in the thread I mentioned we should write to the allocated memory (seems so long ago

My "javascript" test just allocates, because when I tried to force write-faults it quit the program - it thought it was stuck in an infinite loop (same happens on the desktop). Limitation in the javascript engine, i guess.

I'm also assuming demand paging, but we haven't seen clear evidence of it yet (since we seem unable to use enough memory to get it do anything), and it does seem to pre-load its default working set, which speaks against a pure demand-paging implementation.

 

[Mike Overbo]

Well, I don't know anything about OSX or the iphone version of OSX, but based on the previous posts it seems like it implements demand-paging, not sure about page swapping.

Oooh, could this be implemented as a function of notifyd, one of the daemon processes? from man 3 notify:

A client using notify_check() to determine when to invalidate a cache.

There's also the section on Shared Memory in apple's VM documentation. I believe that notifyd is the process that's used for governing shared memory...

 

[cmaier]

Cache is different than VM. I don't know what apple means by "shared memory" though it sounds like it would be the equivalent of shared code pages (something like windows dlls?)

Unfortunately both cache and VM use some of the same terminology (at least in academic circles, which is where my knowledge of memory hierarchies is rooted), so it gets confusing.

 

[oalvarez]

think about how much we have learned in this thread's existance. we started with the 10 things that absolutely sucked about the iPhone and are ending with 10 things that many of us know nothing about.

god love TreoCentral

 

[mikec#IM]

over?

Over?

Who said it was over?

Was it over when the Germans bombed Pearl Harbor?

No!

It's not over until we say it's over!

 

[AnteL0pe]

Just curious what are you guys trying to prove?

That pretty much sums up the entire thread.

 

[surur]

Just curious what are you guys trying to prove?

That pretty much sums up the entire thread.

In this particular instance its whether the iPhone is memory constrained or not, which would limit the size for example of the web pages it could load.

In general, its about how the iPhone is not as great as it pretends to be.

Surur

 

[cmaier]

The iPhone doesn't "pretend to be" anything. It's a phone. A mere tool. It doesn't hate you. It didn't beat you up in third grade. Now, Archie and Jobs might pretend it's greater than it is, but that's a different story entirely.

As for me, I'm just happy I can write code for the thing to make it do what *I* want. The rest of the fools that bought them hoping that Apple will someday make it do what *they* want are... fools. Those who bought it because it already did what *they* want are not fools (but probably are a tad wealthy).

To follow up on mikec's comment: I give this thread a zero point zero.

 

[surur]

The iPhone doesn't "pretend to be" anything.

Steve Jobs said to expect three things: "an incredibly great cell phone," "the best iPod we've ever made" and "the Internet in your pocket."

Surur

 

[cmaier]

Yes. You know the iPhone isn't Steve Jobs, right? I mean, I've seen them both in the same place at the same time.

 

[oalvarez]

Quote:
Steve Jobs said to expect three things: "an incredibly great cell phone," "the best iPod we've ever made" and "the Internet in your pocket."

Surur

i'm not sure it's an incredibly great phone (definitely a good one), it might be the best iPod they've ever made, and it does offer an incredibly great internet experience while being very pocketable.

so what was the point you were trying to make?

 

[whmurray]

Over?

Who said it was over?

Was it over when the Germans bombed Pearl Harbor?

No!

It's not over until we say it's over!

Germans? Pearl Harbor?

 

[surur]

142 pages says all 3 claims can be disputed.

Surur