* Prasad Joshi <prasadjoshi124@xxxxxxxxx> wrote: > I am not sure how to induce the delay you mentioned. [...] In the simplest version just add: if (debug__io_delay) udelay(1000); to the code that does a read() from the disk image. This will introduce a 1 msec delay - that should be plenty enough to simulate most effects of IO delays. Later on you could complicate it with some disk geometry approximation: delay = read_size_in_kb; /* 1 usec per KB read */ delay += seek_distance_in_kb; /* 1 usec per KB disk-head movement */ udelay(delay); Where 'read_size_in_kb' is the number of bytes read in KB, while seek_distance_in_kb measures the position of the the last byte read by the previous read() call to the first byte of the current read(). ( Also, instead of copying the disk image to /dev/shm you could add a debug switch to mmap() and mlock() it directly. Assuming there's enough RAM in the box. ) But i'd strongly suggest to keep the initial version simple. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
