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authorLaszlo Ersek <lersek@redhat.com>2011-10-18 22:42:59 +0200
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-06-28 12:11:39 -0400
commit0b0c002c340e78173789f8afaa508070d838cf3d (patch)
treeb1c81cd6ed7a3da85075ace0f525e3010825d2c6
parent283c0972d53769ee44750cad4c27e3f5fa26ec1f (diff)
downloadlinux-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.c17
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 */