On 08/16/2012 06:08 PM, Greg KH wrote: > On a larger note, I _really_ don't want a set of 'delete and then add it > back' set of patches. That destroys all of the work that people had > done up until now on the code base. > > I understand your need, and want, to start fresh, but you still need to > abide with the "evolve over time" model here. Surely there is some path > from the old to the new codebase that you can find? I very much agree that this is the wrong way to do this. I can't possibly inspect the code changes in this format, so I'll just comment on some high level changes and mention some performance results. I like frontswap reclaiming memory from cleancache. I think that would work better than having the pages go back to the kernel-wide page pool using the shrinker interface. That being said, I can't test the impact of this alone because all these changes are being submitted together. I also like the sysfs->debugfs cleanup and zbud being moved into its own file. I do _not_ support replacing zsmalloc with zbud: https://lkml.org/lkml/2012/8/14/347 I do not support the integration of ramster mixed in with all the rest of these changes. I have no way to see or measure the impact of the ramster code. I ran my kernel building benchmark twice on an unmodified v3.5 kernel with zcache and then with these changes. On none-low memory pressure, <16 threads, they worked roughly the same with low swap volume. However, in mid-high pressure, >20 threads, these changes degraded zcache runtime and I/O savings by 30-80%. I would suspect the low-density storage of zbud as the culprit; however I can't confirm this because, again, it all one huge change. Some smaller issues: 1. This patchset breaks the build when CONFIG_SWAP in not set. FRONTSWAP depends on SWAP, but ZCACHE _selects_ FRONTSWAP. If ZCACHE is selected and FRONTSWAP can't be selected because SWAP isn't selected, then there is a break. 2. I get about 8 unsued/uninit'ed variable warnings at compile time. So I can't support this patchset, citing the performance degradation and the fact that this submission is unreviewable due to it being one huge monolithic patchset on top of an existing codebase. Seth -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>