> From: Paolo Bonzini [mailto:pbonz...@redhat.com] > On 07/11/2014 11:32, Pavel Dovgalyuk wrote: > > Replay uses number of executed instructions to determine corrent events > > injection moments. This patch introduces new function for querying the > > instructions counter. > > > > Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru> > > --- > > cpus.c | 26 +++++++++++++++++++++++--- > > include/qemu/timer.h | 1 + > > 2 files changed, 24 insertions(+), 3 deletions(-) > > > > diff --git a/cpus.c b/cpus.c > > index 7e8c507..2ec6d75 100644 > > --- a/cpus.c > > +++ b/cpus.c > > @@ -136,8 +136,7 @@ typedef struct TimersState { > > > > static TimersState timers_state; > > > > -/* Return the virtual CPU time, based on the instruction counter. */ > > -static int64_t cpu_get_icount_locked(void) > > +static int64_t cpu_get_instructions_counter_locked(void) > > { > > int64_t icount; > > CPUState *cpu = current_cpu; > > @@ -145,10 +144,31 @@ static int64_t cpu_get_icount_locked(void) > > icount = timers_state.qemu_icount; > > if (cpu) { > > if (!cpu_can_do_io(cpu)) { > > - fprintf(stderr, "Bad clock read\n"); > > + fprintf(stderr, "Bad icount read\n"); > > + exit(1); > > } > > icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); > > } > > + return icount; > > +} > > + > > +int64_t cpu_get_instructions_counter(void) > > +{ > > + /* This function calls are synchnonized to timer changes, > > + calling cpu_get_instructions_counter_locked without lock is safe */ > > + int64_t icount = timers_state.qemu_icount; > > + CPUState *cpu = current_cpu; > > + > > + if (cpu) { > > + icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); > > + } > > + return icount; > > +} > > This is the same as Frederic's QEMU_CLOCK_ICOUNT clock, right? Any > reason why one is better than the other?
Not really. Frederic's QEMU_CLOCK_ICOUNT is measured in nanoseconds. And this counter is measured in instructions. Pavel Dovgalyuk
