Mike Lambert wote: > Run languages/basic/basic.pl. > Type "LOAD WUMPUS, and hit return. > Type "RUN", and hit return. > Type "N" and hit return.
The thot plickens! My results for the above are: Interpreter version Time Data size CVS 8s 1320kB CVS + ML COW 20s 19172kB CVS + Grey1 5s 1884kB CVS + ML COW - reclaimable check ?? 5952kB Time is approximate time from entering N to reaching user input stage. Data size is measured when sleeping at the same point. So I saw only a small increase in memory size with grey cows, whereas you saw a much larger increase doing the same. One culprit is the check in mem_allocate that does not bother to compact the pool if the saving is insufficient. Because you are under-estimating the reclaimable amount, this check actually prevents the pool from being compacted at all after a certain point during the above test. The last line above reflects the results from removing the two checks on reclaimable (threshold and size) This problem does not exist in my version because I have not bothered to adjust the reclaimable memory calculation, as it changes again as part of the paged memory allocation code that is next on my list to migrate from my old version to my new version. I simply changed the code in compact_pool to ignore reclaimable for calculating the size to allocate, as the simplest interim solution. This means I always overestimate reclaimable, and therefore compact more often than I need to. However, even with that problem bypassed, there is still a major increase in memory usage. I put a few debugging statements in resources.c to track block allocs and frees; the value of interpreter->memory_allocated when wumpus reaches its idle state waiting for user input are as follows: CVS = 121,780 CVS + ML COW = 18,556,096 CVS + ML COW - reclaimable check = 2,197,359 (peak was about 6.2MB) So the memory is definitely being allocated to the buffer pool, not some other weird memory allocations somewhere. I am still trying to track it down further - there is definitely something very strange happening here somewhere. I suspect a combination of slower and fatter may make it hard to persuade Dan that we need cows? -- Peter Gibbs EmKel Systems
