On Fri, 2 Mar 2007, Nick Piggin wrote: > So what do you mean by efficient? I guess you aren't talking about CPU > efficiency, because even if you make the IO subsystem submit larger > physical IOs, you still have to deal with 256 billion TLB entries, the > pagecache has to deal with 256 billion struct pages, so does the > filesystem code to build the bios.
You do not have to deal with TLB entries if you do buffered I/O. For mmapped I/O you would want to transparently use 2M TLBs if the page size is large. > So you are having problems with your IO controller's handling of sg > lists? We currently have problems with the kernel limits of 128 SG entries but the fundamental issue is that we can only do 2 Meg of I/O in one go given the default limits of the block layer. Typically the number of hardware SG entrie is also limited. We never will be able to put a - 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/
