icount: document (future) locking rules for icount

Reviewed-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-10-07 17:18:15 +02:00
parent ce78d18ced
commit a3270e19cc

15
cpus.c
View File

@ -98,17 +98,22 @@ static bool all_cpu_threads_idle(void)
/***********************************************************/
/* guest cycle counter */
/* Protected by TimersState seqlock */
/* Compensate for varying guest execution speed. */
static int64_t qemu_icount_bias;
static int64_t vm_clock_warp_start;
/* Conversion factor from emulated instructions to virtual clock ticks. */
static int icount_time_shift;
/* Arbitrarily pick 1MIPS as the minimum allowable speed. */
#define MAX_ICOUNT_SHIFT 10
/* Compensate for varying guest execution speed. */
static int64_t qemu_icount_bias;
/* Only written by TCG thread */
static int64_t qemu_icount;
static QEMUTimer *icount_rt_timer;
static QEMUTimer *icount_vm_timer;
static QEMUTimer *icount_warp_timer;
static int64_t vm_clock_warp_start;
static int64_t qemu_icount;
typedef struct TimersState {
/* Protected by BQL. */
@ -235,6 +240,8 @@ static void icount_adjust(void)
int64_t cur_time;
int64_t cur_icount;
int64_t delta;
/* Protected by TimersState mutex. */
static int64_t last_delta;
/* If the VM is not running, then do nothing. */