From: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>,
Julien Grall <julien@xen.org>, Wei Liu <wl@xen.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ian Jackson <ian.jackson@eu.citrix.com>,
George Dunlap <george.dunlap@citrix.com>,
Dario Faggioli <dfaggioli@suse.com>,
Jan Beulich <jbeulich@suse.com>,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
Subject: [RFC PATCH v1 4/6] xentop: collect IRQ and HYP time statistics.
Date: Fri, 12 Jun 2020 00:22:37 +0000 [thread overview]
Message-ID: <20200612002205.174295-5-volodymyr_babchuk@epam.com> (raw)
In-Reply-To: <20200612002205.174295-1-volodymyr_babchuk@epam.com>
As scheduler code now collects time spent in IRQ handlers and in
do_softirq(), we can present those values to userspace tools like
xentop, so system administrator can see how system behaves.
We are updating counters only in sched_get_time_correction() function
to minimize number of taken spinlocks. As atomic_t is 32 bit wide, it
is not enough to store time with nanosecond precision. So we need to
use 64 bit variables and protect them with spinlock.
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
---
xen/common/sched/core.c | 17 +++++++++++++++++
xen/common/sysctl.c | 1 +
xen/include/public/sysctl.h | 4 +++-
xen/include/xen/sched.h | 2 ++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/xen/common/sched/core.c b/xen/common/sched/core.c
index a7294ff5c3..ee6b1d9161 100644
--- a/xen/common/sched/core.c
+++ b/xen/common/sched/core.c
@@ -95,6 +95,10 @@ static struct scheduler __read_mostly ops;
static bool scheduler_active;
+static DEFINE_SPINLOCK(sched_stat_lock);
+s_time_t sched_stat_irq_time;
+s_time_t sched_stat_hyp_time;
+
static void sched_set_affinity(
struct sched_unit *unit, const cpumask_t *hard, const cpumask_t *soft);
@@ -994,9 +998,22 @@ s_time_t sched_get_time_correction(struct sched_unit *u)
break;
}
+ spin_lock_irqsave(&sched_stat_lock, flags);
+ sched_stat_irq_time += irq;
+ sched_stat_hyp_time += hyp;
+ spin_unlock_irqrestore(&sched_stat_lock, flags);
+
return irq + hyp;
}
+void sched_get_time_stats(uint64_t *irq_time, uint64_t *hyp_time)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sched_stat_lock, flags);
+ *irq_time = sched_stat_irq_time;
+ *hyp_time = sched_stat_hyp_time;
+ spin_unlock_irqrestore(&sched_stat_lock, flags);
}
/*
diff --git a/xen/common/sysctl.c b/xen/common/sysctl.c
index 1c6a817476..00683bc93f 100644
--- a/xen/common/sysctl.c
+++ b/xen/common/sysctl.c
@@ -270,6 +270,7 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl)
pi->scrub_pages = 0;
pi->cpu_khz = cpu_khz;
pi->max_mfn = get_upper_mfn_bound();
+ sched_get_time_stats(&pi->irq_time, &pi->hyp_time);
arch_do_physinfo(pi);
if ( iommu_enabled )
{
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 3a08c512e8..f320144d40 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -35,7 +35,7 @@
#include "domctl.h"
#include "physdev.h"
-#define XEN_SYSCTL_INTERFACE_VERSION 0x00000013
+#define XEN_SYSCTL_INTERFACE_VERSION 0x00000014
/*
* Read console content from Xen buffer ring.
@@ -118,6 +118,8 @@ struct xen_sysctl_physinfo {
uint64_aligned_t scrub_pages;
uint64_aligned_t outstanding_pages;
uint64_aligned_t max_mfn; /* Largest possible MFN on this host */
+ uint64_aligned_t irq_time;
+ uint64_aligned_t hyp_time;
uint32_t hw_cap[8];
};
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 51dc7c4551..869d4efbd6 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -717,6 +717,8 @@ void vcpu_end_irq_handler(void);
void vcpu_begin_hyp_task(struct vcpu *v);
void vcpu_end_hyp_task(struct vcpu *v);
+void sched_get_time_stats(uint64_t *irq_time, uint64_t *hyp_time);
+
/*
* Force synchronisation of given VCPU's state. If it is currently descheduled,
* this call will ensure that all its state is committed to memory and that
--
2.27.0
next prev parent reply other threads:[~2020-06-12 0:23 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-12 0:22 [RFC PATCH v1 0/6] Fair scheduling Volodymyr Babchuk
2020-06-12 0:22 ` [RFC PATCH v1 2/6] sched: track time spent in hypervisor tasks Volodymyr Babchuk
2020-06-12 4:43 ` Jürgen Groß
2020-06-12 11:30 ` Volodymyr Babchuk
2020-06-12 11:40 ` Jürgen Groß
2020-09-24 18:08 ` Volodymyr Babchuk
2020-09-25 17:22 ` Dario Faggioli
2020-09-25 20:21 ` Volodymyr Babchuk
2020-09-25 21:42 ` Dario Faggioli
2020-06-16 10:10 ` Jan Beulich
2020-06-18 2:50 ` Volodymyr Babchuk
2020-06-18 6:34 ` Jan Beulich
2020-06-12 0:22 ` [RFC PATCH v1 1/6] sched: track time spent in IRQ handler Volodymyr Babchuk
2020-06-12 4:36 ` Jürgen Groß
2020-06-12 11:26 ` Volodymyr Babchuk
2020-06-12 11:29 ` Julien Grall
2020-06-12 11:33 ` Volodymyr Babchuk
2020-06-12 12:21 ` Julien Grall
2020-06-12 20:08 ` Dario Faggioli
2020-06-12 22:25 ` Volodymyr Babchuk
2020-06-12 22:54 ` Julien Grall
2020-06-16 10:06 ` Jan Beulich
2020-06-12 0:22 ` [RFC PATCH v1 3/6] sched, credit2: improve scheduler fairness Volodymyr Babchuk
2020-06-12 4:51 ` Jürgen Groß
2020-06-12 11:38 ` Volodymyr Babchuk
2020-06-12 0:22 ` [RFC PATCH v1 5/6] tools: xentop: show time spent in IRQ and HYP states Volodymyr Babchuk
2020-06-12 0:22 ` [RFC PATCH v1 6/6] trace: add fair scheduling trace events Volodymyr Babchuk
2020-06-12 0:22 ` Volodymyr Babchuk [this message]
2020-06-12 4:57 ` [RFC PATCH v1 4/6] xentop: collect IRQ and HYP time statistics Jürgen Groß
2020-06-12 11:44 ` Volodymyr Babchuk
2020-06-12 12:45 ` Julien Grall
2020-06-12 22:16 ` Volodymyr Babchuk
2020-06-18 20:24 ` Volodymyr Babchuk
2020-06-18 20:34 ` Julien Grall
2020-06-18 23:35 ` Volodymyr Babchuk
2020-06-12 12:29 ` Julien Grall
2020-06-12 12:41 ` Jürgen Groß
2020-06-12 15:29 ` Dario Faggioli
2020-06-12 22:27 ` Volodymyr Babchuk
2020-06-13 6:22 ` Jürgen Groß
2020-06-18 2:58 ` Volodymyr Babchuk
2020-06-18 15:17 ` Julien Grall
2020-06-18 15:23 ` Jan Beulich
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