diff options
| author | Laszlo Ersek <lersek@redhat.com> | 2011-10-18 22:42:59 +0200 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-06-28 12:11:39 -0400 |
| commit | 0b0c002c340e78173789f8afaa508070d838cf3d (patch) | |
| tree | b1c81cd6ed7a3da85075ace0f525e3010825d2c6 | |
| parent | 283c0972d53769ee44750cad4c27e3f5fa26ec1f (diff) | |
| download | linux-0b0c002c340e78173789f8afaa508070d838cf3d.tar.bz2 | |
xen/time: remove blocked time accounting from xen "clockchip"
... because the "clock_event_device framework" already accounts for idle
time through the "event_handler" function pointer in
xen_timer_interrupt().
The patch is intended as the completion of [1]. It should fix the double
idle times seen in PV guests' /proc/stat [2]. It should be orthogonal to
stolen time accounting (the removed code seems to be isolated).
The approach may be completely misguided.
[1] https://lkml.org/lkml/2011/10/6/10
[2] http://lists.xensource.com/archives/html/xen-devel/2010-08/msg01068.html
John took the time to retest this patch on top of v3.10 and reported:
"idle time is correctly incremented for pv and hvm for the normal
case, nohz=off and nohz=idle." so lets put this patch in.
CC: stable@vger.kernel.org
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| -rw-r--r-- | arch/x86/xen/time.c | 17 |
1 files changed, 2 insertions, 15 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index aec0b14b6d76..a690868be837 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -37,9 +37,8 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); /* snapshots of runstate info */ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot); -/* unused ns of stolen and blocked time */ +/* unused ns of stolen time */ static DEFINE_PER_CPU(u64, xen_residual_stolen); -static DEFINE_PER_CPU(u64, xen_residual_blocked); /* return an consistent snapshot of 64-bit time/counter value */ static u64 get64(const u64 *p) @@ -116,7 +115,7 @@ static void do_stolen_accounting(void) { struct vcpu_runstate_info state; struct vcpu_runstate_info *snap; - s64 blocked, runnable, offline, stolen; + s64 runnable, offline, stolen; cputime_t ticks; get_runstate_snapshot(&state); @@ -126,7 +125,6 @@ static void do_stolen_accounting(void) snap = &__get_cpu_var(xen_runstate_snapshot); /* work out how much time the VCPU has not been runn*ing* */ - blocked = state.time[RUNSTATE_blocked] - snap->time[RUNSTATE_blocked]; runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable]; offline = state.time[RUNSTATE_offline] - snap->time[RUNSTATE_offline]; @@ -142,17 +140,6 @@ static void do_stolen_accounting(void) ticks = iter_div_u64_rem(stolen, NS_PER_TICK, &stolen); __this_cpu_write(xen_residual_stolen, stolen); account_steal_ticks(ticks); - - /* Add the appropriate number of ticks of blocked time, - including any left-overs from last time. */ - blocked += __this_cpu_read(xen_residual_blocked); - - if (blocked < 0) - blocked = 0; - - ticks = iter_div_u64_rem(blocked, NS_PER_TICK, &blocked); - __this_cpu_write(xen_residual_blocked, blocked); - account_idle_ticks(ticks); } /* Get the TSC speed from Xen */ |