cpu-exec: simplify init_delay_params

With the introduction of QEMU_CLOCK_VIRTUAL_RT, the computation of
sc->diff_clk can be simplified nicely:

        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) -
        qemu_clock_get_ns(QEMU_CLOCK_REALTIME) +
        cpu_get_clock_offset()

     =  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) -
        (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - cpu_get_clock_offset())

     =  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) -
        (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timers_state.cpu_clock_offset)

     =  qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) -
        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT)

Cc: Sebastian Tanase <sebastian.tanase@openwide.fr>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-01-28 10:16:37 +01:00
parent a498d0ef37
commit 2e91cc62f2
3 changed files with 2 additions and 22 deletions

View File

@ -100,10 +100,8 @@ static void init_delay_params(SyncClocks *sc,
if (!icount_align_option) {
return;
}
sc->realtime_clock = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
sc->diff_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) -
sc->realtime_clock +
cpu_get_clock_offset();
sc->realtime_clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT);
sc->diff_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - sc->realtime_clock;
sc->last_cpu_icount = cpu->icount_extra + cpu->icount_decr.u16.low;
if (sc->diff_clk < max_delay) {
max_delay = sc->diff_clk;

17
cpus.c
View File

@ -229,23 +229,6 @@ int64_t cpu_get_clock(void)
return ti;
}
/* return the offset between the host clock and virtual CPU clock */
int64_t cpu_get_clock_offset(void)
{
int64_t ti;
unsigned start;
do {
start = seqlock_read_begin(&timers_state.vm_clock_seqlock);
ti = timers_state.cpu_clock_offset;
if (!timers_state.cpu_ticks_enabled) {
ti -= get_clock();
}
} while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start));
return -ti;
}
/* enable cpu_get_ticks()
* Caller must hold BQL which server as mutex for vm_clock_seqlock.
*/

View File

@ -838,7 +838,6 @@ static inline int64_t get_clock(void)
int64_t cpu_get_icount_raw(void);
int64_t cpu_get_icount(void);
int64_t cpu_get_clock(void);
int64_t cpu_get_clock_offset(void);
int64_t cpu_icount_to_ns(int64_t icount);
/*******************************************/