MinimalMorphic based web images

>> One thing that I've noticed in these images is that they use the CPU
>> every second or two for something. As I watch the system monitor I can
>> see the CPU use jump very slightly, very regularly. I don't remember if
>> there is a way to stop this or not. Any help with this is greatly
>> appreciated.
>
> IIRC what Seaside Hosting does is suspend them at the operating system
> process level using daemontools [1] to make sure they're idle and the
> operating system can swap them out.
>
> [1] http://cr.yp.to/daemontools.html

> Philippe Marschall wrote:
> > 2007/10/15, Jimmie Houchin <[hidden email]>:
> [snip
> >> One thing that I've noticed in these images is that they use the CPU
> >> every second or two for something. As I watch the system monitor I can
> >> see the CPU use jump very slightly, very regularly. I don't remember if
> >> there is a way to stop this or not. Any help with this is greatly
> >> appreciated.
> >
> > IIRC what Seaside Hosting does is suspend them at the operating system
> > process level using daemontools [1] to make sure they're idle and the
> > operating system can swap them out.
> >
> > [1] http://cr.yp.to/daemontools.html
>
>
> Hello Philippe,
>
> Thanks for the reply. Unfortunately, I wasn't very clear, my apologies.
>
> The image seems to be doing some kind of polling which is using CPU even
> when the image should seem to be using none as it is doing nothing.

> I haven't researched the squeak-dev archives yet. But I thought
> something had been done to change the polling behavior in Squeak. I'll
> have to see if I can research that.
>
> Thanks.
>
> Jimmie
>
> _______________________________________________
> seaside mailing list
> [hidden email]
> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
>

> 2007/10/15, Jimmie Houchin <[hidden email]>:
>> Philippe Marschall wrote:
>>> 2007/10/15, Jimmie Houchin <[hidden email]>:
>> [snip
>>>> One thing that I've noticed in these images is that they use the  
>>>> CPU
>>>> every second or two for something. As I watch the system monitor  
>>>> I can
>>>> see the CPU use jump very slightly, very regularly. I don't  
>>>> remember if
>>>> there is a way to stop this or not. Any help with this is greatly
>>>> appreciated.
>>>
>>> IIRC what Seaside Hosting does is suspend them at the operating  
>>> system
>>> process level using daemontools [1] to make sure they're idle and  
>>> the
>>> operating system can swap them out.
>>>
>>> [1] http://cr.yp.to/daemontools.html
>>
>>
>> Hello Philippe,
>>
>> Thanks for the reply. Unfortunately, I wasn't very clear, my  
>> apologies.
>>
>> The image seems to be doing some kind of polling which is using  
>> CPU even
>> when the image should seem to be using none as it is doing nothing.
>
> Could be anything. At lest the gc will have to do same work from time
> to time. But it is also very likely the UI is not completely idle as
> well. That's my Seaside Hosting suspends the whole process to make
> everything is really idle and nothing happens.

>
> Cheers
> Philippe
>
>> I haven't researched the squeak-dev archives yet. But I thought
>> something had been done to change the polling behavior in Squeak.  
>> I'll
>> have to see if I can research that.
>>
>> Thanks.
>>
>> Jimmie
>>
>> _______________________________________________
>> seaside mailing list
>> [hidden email]
>> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside
>>
> _______________________________________________
> seaside mailing list
> [hidden email]
> http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/seaside

>>> Hello Philippe,
>>>
>>> Thanks for the reply. Unfortunately, I wasn't very clear, my apologies.
>>>
>>> The image seems to be doing some kind of polling which is using CPU even
>>> when the image should seem to be using none as it is doing nothing.
>>
>> Could be anything. At lest the gc will have to do same work from time
>> to time. But it is also very likely the UI is not completely idle as
>> well. That's my Seaside Hosting suspends the whole process to make
>> everything is really idle and nothing happens.
>
> Very likely it's the UI loop (GC activity depends on number of
> instantiated objects, not on time elapsed). You can suspend/resume the
> UI process, for example with the Seaside snapshot application, if you
> want to spare some cycles (which can be significant as soon as you have
> many images).
>
> Oh, and make sure that the preference named betterPerformance is turned
> _off_.

> Adrian Lienhard wrote:
>> On Oct 17, 2007, at 07:02 , Philippe Marschall wrote:
>>> 2007/10/15, Jimmie Houchin <[hidden email]>:
>>>> Philippe Marschall wrote:
>>>>> 2007/10/15, Jimmie Houchin <[hidden email]>:
> [snip]
>>>> Hello Philippe,
>>>>
>>>> Thanks for the reply. Unfortunately, I wasn't very clear, my  
>>>> apologies.
>>>>
>>>> The image seems to be doing some kind of polling which is using  
>>>> CPU even
>>>> when the image should seem to be using none as it is doing nothing.
>>>
>>> Could be anything. At lest the gc will have to do same work from  
>>> time
>>> to time. But it is also very likely the UI is not completely idle as
>>> well. That's my Seaside Hosting suspends the whole process to make
>>> everything is really idle and nothing happens.
>> Very likely it's the UI loop (GC activity depends on number of  
>> instantiated objects, not on time elapsed). You can suspend/resume  
>> the UI process, for example with the Seaside snapshot application,  
>> if you want to spare some cycles (which can be significant as soon  
>> as you have many images).
>> Oh, and make sure that the preference named betterPerformance is  
>> turned _off_.
>
> Hello Adrian,
>
> Thanks for the reply. From my playing around with suspending the UI  
> it does seem to be the UI loop causing the regular (once a second  
> or so) 2-5% spike in CPU. Suspending UI makes the Squeak process  
> flat until serving something.
>
> As I am hoping to get Squeak/Seaside hosting on my web host  
> provider, this is a very important issue.
>
> I am glad you made me aware of that setting. Is that the setting  
> where Squeak decides to be more aggressive on its CPU use? I am  
> sure a hosting provider would definitely want that turned off.

>>> Very likely it's the UI loop (GC activity depends on number of
>>> instantiated objects, not on time elapsed). You can suspend/resume
>>> the UI process, for example with the Seaside snapshot application, if
>>> you want to spare some cycles (which can be significant as soon as
>>> you have many images).
>>> Oh, and make sure that the preference named betterPerformance is
>>> turned _off_.
>>
>> Hello Adrian,
>>
>> Thanks for the reply. From my playing around with suspending the UI it
>> does seem to be the UI loop causing the regular (once a second or so)
>> 2-5% spike in CPU. Suspending UI makes the Squeak process flat until
>> serving something.
>>
>> As I am hoping to get Squeak/Seaside hosting on my web host provider,
>> this is a very important issue.
>>
>> I am glad you made me aware of that setting. Is that the setting where
>> Squeak decides to be more aggressive on its CPU use? I am sure a
>> hosting provider would definitely want that turned off.
>
> Actually, the preference is named #higherPerformance (not
> betterPerformance). The UI loops with a default delay of 20ms. If this
> preference is enabled, it loops with 1ms (which makes absolutely no
> sense on a server). By default it should be turned off (in the 3.9
> process it once was accidentally turned on, which caused me some
> headache until I found the cause for the sudden much higher CPU use).
>
> Cheers,
> Adrian
>
> PS: This is also related to a problem I recently had on a production
> application where sometimes Seaside suddenly stopped serving (see
> http://bugs.squeak.org/view.php?id=6581). While the problem was quite
> complex to debug, the fix I use is trivial: just increase the cycle
> pause to 50ms...