lkml.org 
[lkml]   [2020]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/5] x86/vmware: Enable steal time accounting
Date
Set paravirt_steal_rq_enabled if steal clock present.
paravirt_steal_rq_enabled is used in sched/core.c to
adjust task progress by offsetting stolen time.
Use 'no-steal-acc' off switch (share same name with KVM)
to disable steal time accounting.

Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
---
Documentation/admin-guide/kernel-parameters.txt | 2 +-
arch/x86/kernel/cpu/vmware.c | 13 ++++++++++++-
2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 87176a90e61a..07fbdccdd77c 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3152,7 +3152,7 @@
[X86,PV_OPS] Disable paravirtualized VMware scheduler
clock and use the default one.

- no-steal-acc [X86,KVM,ARM64] Disable paravirtualized steal time
+ no-steal-acc [X86,PV_OPS,ARM64] Disable paravirtualized steal time
accounting. steal time is computed, but won't
influence scheduler behaviour

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 59459992ad47..0c65d661d88b 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -125,6 +125,7 @@ static struct cyc2ns_data vmware_cyc2ns __ro_after_init;
static int vmw_sched_clock __initdata = 1;
static DEFINE_PER_CPU_DECRYPTED(struct vmware_steal_time, steal_time) __aligned(64);
static bool has_steal_clock;
+static bool steal_acc __initdata = true; /* steal time accounting */

static __init int setup_vmw_sched_clock(char *s)
{
@@ -133,6 +134,13 @@ static __init int setup_vmw_sched_clock(char *s)
}
early_param("no-vmw-sched-clock", setup_vmw_sched_clock);

+static __init int parse_no_stealacc(char *arg)
+{
+ steal_acc = false;
+ return 0;
+}
+early_param("no-steal-acc", parse_no_stealacc);
+
static unsigned long long notrace vmware_sched_clock(void)
{
unsigned long long ns;
@@ -306,8 +314,11 @@ static int vmware_cpu_down_prepare(unsigned int cpu)

static __init int activate_jump_labels(void)
{
- if (has_steal_clock)
+ if (has_steal_clock) {
static_key_slow_inc(&paravirt_steal_enabled);
+ if (steal_acc)
+ static_key_slow_inc(&paravirt_steal_rq_enabled);
+ }

return 0;
}
--
2.14.2
\
 
 \ /
  Last update: 2020-03-20 21:51    [W:0.068 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site