On Thu, Jun 02, 2016 at 11:48:18AM +0530, HRISHIKESH GOYAL wrote: > > another generic problem that will help me considerably is I want to > disable/clear cache memory. I want corresponding to each command in > userland, there is lower level disk read. Which will help me in tracing fs > routines.
This will never happen. You won't even see requests of the same size, because the VM system translates them into ranges of pages and reads ahead/writes behind. About the best you can do is write a test program that uses mmap and madvise(MADV_RANDOM), then touches one page at a time. But then you will never see anything but page-sized I/O requests, which may also not be what you want. Thor
