Hi! I've recently started working with compcache, and have a few questions in addition to a little data to contribute.<br><br>- what's the "sweet spot" for which compcache is most appropriate?<br><br>I've read about using this for netbooks, where CPU is relatively free, it has limited memory, and disk is at a premium.<br>
<br>- for this sweet spot, what's the best test load, to measure performance? How can this be made repeatable?<br><br>The wiki mentions "load Firefox, OpenOffice, and 3 evince windows", but that doesn't sound very repeatable. The "scan" benchmark is very easy to use and is repeatable, but how comparable is it to real-world information?<br>
<br><br>For my tests, I ran three configurations of swap: traditional swap to disk, compcache only, and compcache with disk as backing store. The plot is linked below, and I'm happy to publish data & scripts if that is useful. I found that using compcache completed the workload quite a bit faster than just with disk-based swap, and compcache+backing store was faster. <br>
<br>However, I realized that the numbers can be *very* specific to differing sizes of RAM, compcache, swap disk, and workload. Nor do I trust that "swapping is faster" is a concrete metric to optimize.<br><br><br>
** How can I tune my system and load to best get results from compcache? For a VM, how much 1) RAM, 2) swap disk, and 3) how much compcache allocation? What's the test load?<br><br><br>Thanks so much!<br>- john<br><br>
<br><br>Testing done under Linux VM (KVM), compcache-0.5.3<br><br>- VM details:<br> . 128 MiB RAM, swap: ~152 MiB<br> . 1 CPU, QEMU 0.9.1<br> . Ubuntu 9.04 (kernel 2.6.28-11-generic)<br> . disk ~20 MB.sec buffered disk reads ("hdparm -Tt")<br>
<br>- Host details:<br> . Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz<br> . Ubuntu 9.04 (kernel 2.6.28-11-generic)<br><br>Testing details<br><br>- full boot, runlevel 5<br>- run "scan 152 2" (ie allocate 152MiB and scan twice)<br>
- run above test once for: disk based swap, ramzswap, and ramzswap with backing store<br><br><br><a href="http://www.flickr.com/photos/shavenwarthog/3618101530/">http://www.flickr.com/photos/shavenwarthog/3618101530/</a><br>
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