On Fri, 31 August 2007 18:41:07 -0700, Christoph Lameter wrote: > > The trouble with this patchset is that it is difficult to validate. > Activities are only performed when special load situations are encountered. > Are there any tests that could give meaningful information about > the effectiveness of these measures? I have run various tests here > creating and deleting files and building kernels under low memory situations > to trigger these reclaim mechanisms but how does one measure their > effectiveness? One could play with updatedb followed by a memhog. How much time passes and how many slab objects have to be freed before the memhog has allocated N% of physical memory? Both numbers are relevant. The first indicates how quickly pages are reclaimed from slab caches, while the second show how many objects remain cached for future lookups. Updatedb aside, caching objects is done for solid performance reasons. Creating a qemu image with little memory and a huge directory hierarchy filled with 0-byte files may be a nice test system. Unless you beat me to it I'll try to set it up once logfs is in merge-worthy shape. Jörn -- A quarrel is quickly settled when deserted by one party; there is no battle unless there be two. -- Seneca - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
