On Tue, Jul 17, 2007 at 10:47:37AM -0700, William Lee Irwin III wrote: > You may rest assured that it's technically feasible. It's been done. > The larger obstacles to all this are nontechnical.
Back then there was no variable order page size proposal, no slub, generally nothing of that kind. I think these days it worth to get it working again and solve the technical obstacles once more time. Then we should plug into it a pagecache logic to handle small files. That means if the soft page size is 64k, we should kmalloc 32k of pagecache if the file is < 64k but >= 32k, or kmalloc 16k if the file is < 32k but >= 16k, etc... Down to 32bytes if we memcpy the 32bytes away to a 64k page, and we disable the logic the moment somebody attempts to mmap the "kmalloced" pagecache (which I think it's a lot simpler than trying to mmap a kmalloced 4k naturally aligned object into userland). I wouldn't call it tail packing, it's more a fine-granular pagecache with the already available kmalloc granularities. That will maximize pagecache utilization with read syscall for hg/git compared to current 2.6.22 plus memory will be allocated faster in 64k chunks etc... Ideally it should be possible to disable the finer-granular-kmalloc-pagecache on the big irons with lots of memory and only working with big files. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/