[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] hvm: Split no_missed_tick_accounting into two modes:
# HG changeset patch # User Keir Fraser <keir.fraser@xxxxxxxxxx> # Date 1196942211 0 # Node ID 0f9b5ab59579e8b980e231bfd3fdf5ab8a74e005 # Parent d7a0a73e5dca64466843a420a3975ecf665d4762 hvm: Split no_missed_tick_accounting into two modes: * no_missed_ticks_pending ('SYNC') * one_missed_tick_pending ('MIXED') This is based on a patch by Dave Winchell <dwinchell@xxxxxxxxxxxxxxx> Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx> --- xen/arch/x86/hvm/hvm.c | 4 +--- xen/arch/x86/hvm/vpt.c | 13 ++++++++++--- xen/include/asm-x86/hvm/vpt.h | 1 + xen/include/public/hvm/params.h | 12 +++++++++--- 4 files changed, 21 insertions(+), 9 deletions(-) diff -r d7a0a73e5dca -r 0f9b5ab59579 xen/arch/x86/hvm/hvm.c --- a/xen/arch/x86/hvm/hvm.c Thu Dec 06 11:29:18 2007 +0000 +++ b/xen/arch/x86/hvm/hvm.c Thu Dec 06 11:56:51 2007 +0000 @@ -1874,9 +1874,7 @@ long do_hvm_op(unsigned long op, XEN_GUE break; case HVM_PARAM_TIMER_MODE: rc = -EINVAL; - if ( (a.value != HVMPTM_delay_for_missed_ticks) && - (a.value != HVMPTM_no_delay_for_missed_ticks) && - (a.value != HVMPTM_no_missed_tick_accounting) ) + if ( a.value > HVMPTM_one_missed_tick_pending ) goto param_fail; break; } diff -r d7a0a73e5dca -r 0f9b5ab59579 xen/arch/x86/hvm/vpt.c --- a/xen/arch/x86/hvm/vpt.c Thu Dec 06 11:29:18 2007 +0000 +++ b/xen/arch/x86/hvm/vpt.c Thu Dec 06 11:56:51 2007 +0000 @@ -57,7 +57,10 @@ static void pt_process_missed_ticks(stru return; missed_ticks = missed_ticks / (s_time_t) pt->period + 1; - pt->pending_intr_nr += missed_ticks; + if ( mode_is(pt->vcpu->domain, no_missed_ticks_pending) ) + pt->do_not_freeze = !pt->pending_intr_nr; + else + pt->pending_intr_nr += missed_ticks; pt->scheduled += missed_ticks * pt->period; } @@ -92,7 +95,8 @@ void pt_save_timer(struct vcpu *v) spin_lock(&v->arch.hvm_vcpu.tm_lock); list_for_each_entry ( pt, head, list ) - stop_timer(&pt->timer); + if ( !pt->do_not_freeze ) + stop_timer(&pt->timer); pt_freeze_time(v); @@ -217,6 +221,8 @@ void pt_intr_post(struct vcpu *v, struct return; } + pt->do_not_freeze = 0; + if ( pt->one_shot ) { pt->enabled = 0; @@ -224,7 +230,7 @@ void pt_intr_post(struct vcpu *v, struct } else { - if ( mode_is(v->domain, no_missed_tick_accounting) ) + if ( mode_is(v->domain, one_missed_tick_pending) ) { pt->last_plt_gtime = hvm_get_guest_time(v); pt->pending_intr_nr = 0; /* 'collapse' all missed ticks */ @@ -290,6 +296,7 @@ void create_periodic_time( pt->enabled = 1; pt->pending_intr_nr = 0; + pt->do_not_freeze = 0; /* Periodic timer must be at least 0.9ms. */ if ( (period < 900000) && !one_shot ) diff -r d7a0a73e5dca -r 0f9b5ab59579 xen/include/asm-x86/hvm/vpt.h --- a/xen/include/asm-x86/hvm/vpt.h Thu Dec 06 11:29:18 2007 +0000 +++ b/xen/include/asm-x86/hvm/vpt.h Thu Dec 06 11:56:51 2007 +0000 @@ -74,6 +74,7 @@ struct periodic_time { struct list_head list; char enabled; char one_shot; /* one shot time */ + char do_not_freeze; u8 irq; struct vcpu *vcpu; /* vcpu timer interrupt delivers to */ u32 pending_intr_nr; /* the couner for pending timer interrupts */ diff -r d7a0a73e5dca -r 0f9b5ab59579 xen/include/public/hvm/params.h --- a/xen/include/public/hvm/params.h Thu Dec 06 11:29:18 2007 +0000 +++ b/xen/include/public/hvm/params.h Thu Dec 06 11:56:51 2007 +0000 @@ -67,13 +67,19 @@ * As above, missed interrupts are delivered, but guest time always tracks * wallclock (i.e., real) time while doing so. * no_missed_ticks_pending: - * No more than one missed interrupt is held pending, and guest time always - * tracks wallclock (i.e., real) time. + * No missed interrupts are held pending. Instead, to ensure ticks are + * delivered at some non-zero rate, if we detect missed ticks then the + * internal tick alarm is not disabled if the VCPU is preempted during the + * next tick period. + * one_missed_tick_pending: + * Missed interrupts are collapsed together and delivered as one 'late tick'. + * Guest time always tracks wallclock (i.e., real) time. */ #define HVM_PARAM_TIMER_MODE 10 #define HVMPTM_delay_for_missed_ticks 0 #define HVMPTM_no_delay_for_missed_ticks 1 -#define HVMPTM_no_missed_tick_accounting 2 +#define HVMPTM_no_missed_ticks_pending 2 +#define HVMPTM_one_missed_tick_pending 3 #define HVM_NR_PARAMS 11 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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