Comments on: Hotspot vs. virtual memory http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/ Roman Kennke's ramblings Tue, 06 Jan 2009 21:05:31 +0000 http://wordpress.org/?v=2.5 By: roman http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/#comment-64837 roman Fri, 12 Sep 2008 19:29:11 +0000 http://kennke.org/blog/?p=191#comment-64837 Check out this blog entry, it was interesting: http://blogs.sun.com/jonthecollector/entry/our_collectors I (Stølsvik) made some comments that got replied to, you might find some of that interesting. Check out this blog entry, it was interesting:
http://blogs.sun.com/jonthecollector/entry/our_collectors

I (Stølsvik) made some comments that got replied to, you might find
some of that interesting.

]]> By: Jess Sightler http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/#comment-64761 Jess Sightler Fri, 08 Aug 2008 19:26:44 +0000 http://kennke.org/blog/?p=191#comment-64761 Eclipse does that intentionally. The alternative tends to be much worse. Because in the Java VM (and all GC'ed managed languages that I've seen) the GC will tend to crawl a large area of the used memory every time it runs. If this memory happens to be RAM that is swapped to disk, then you get mad swapping, and likely a complete app freeze while it works. Eclipse used to be famous for this, as you'd switch to Firefox for a minute or two, then when you switched back to Eclipse you'd get the "white menu bar of doom" while it swapped everything back into memory for a GC sweep. There are some workarounds, but they all basically involve the symptom that you describe, as they just heavily discourage the OS from swapping out your block of RAM. I believe that Eclipse started using these workarounds on windows a couple of releases ago. In general, VMs and Swap interact very badly, and this is just a sympton of that. Eclipse does that intentionally. The alternative tends to be much worse. Because in the Java VM (and all GC’ed managed languages that I’ve seen) the GC will tend to crawl a large area of the used memory every time it runs. If this memory happens to be RAM that is swapped to disk, then you get mad swapping, and likely a complete app freeze while it works.

Eclipse used to be famous for this, as you’d switch to Firefox for a minute or two, then when you switched back to Eclipse you’d get the “white menu bar of doom” while it swapped everything back into memory for a GC sweep.

There are some workarounds, but they all basically involve the symptom that you describe, as they just heavily discourage the OS from swapping out your block of RAM. I believe that Eclipse started using these workarounds on windows a couple of releases ago.

In general, VMs and Swap interact very badly, and this is just a sympton of that.

]]> By: Hotspot vs. virtual memory http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/#comment-64759 Hotspot vs. virtual memory Fri, 08 Aug 2008 10:45:19 +0000 http://kennke.org/blog/?p=191#comment-64759 [...] http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/ asks Hoosgot, [...] […] http://kennke.org/blog/2008/08/08/hotspot-vs-virtual-memory/ asks Hoosgot, […]

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