Almost 50% less free memory in joyride-2302 compared with Update.1 (708)

[James Cameron]

I've 703 and 2311 available to compare.  Here's a few things I found.

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A test to compare available memory by eliminating buffer cache.

Method: boot, wait for UI to be stable, switch to text console, echo 3 >
/proc/sys/vm/drop_caches, run free(1) and note the "free" column, repeat
a few times.

Result: build 703 has 123528 pages free, build 2311 has 93716 pages
free.

Conclusion: the extra functions in build 2311 over build 703 consume an
extra 30Mb of memory, before any user interaction.

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A test to consume free memory with cache to encourage page out.

Method: with UI stable, in text console use "find /usr -type f -exec cp
{} /tmp/j \;" to consume free memory, in a second text console monitor
free(1) until free memory has reached a minimum, then in the original
text console hit Ctrl/C, echo 3 > /proc/sys/vm/drop_caches, run free(1)
and note the "free" column.

Result: no significant change in free values from previous test.

Conclusion: that without swap backed process pages are probably not
removed from memory.

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I also tried using ps_mem.py to compare memory used by processes, but
the method that ps_mem.py uses has changed as a result of kernel change.

http://dev.laptop.org/~quozl/2008-08-22-ps-mem/ has the samples that I
took, showing how they are difficult to compare.

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James Cameron    mailto:quozl at us.netrek.org     http://quozl.netrek.org/