From: Andrii Anisov <andrii.anisov@gmail.com>
To: xen-devel@lists.xenproject.org
Cc: Stefano Stabellini <sstabellini@kernel.org>,
Andrii Anisov <andrii_anisov@epam.com>, Wei Liu <wl@xen.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
George Dunlap <George.Dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ian Jackson <ian.jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>,
Julien Grall <julien.grall@arm.com>,
Jan Beulich <jbeulich@suse.com>,
Dario Faggioli <dfaggioli@suse.com>
Subject: [Xen-devel] [RFC 7/9] tacc: Introduce a locked interface for guest time
Date: Wed, 11 Sep 2019 13:32:20 +0300 [thread overview]
Message-ID: <1568197942-15374-8-git-send-email-andrii.anisov@gmail.com> (raw)
In-Reply-To: <1568197942-15374-1-git-send-email-andrii.anisov@gmail.com>
From: Andrii Anisov <andrii_anisov@epam.com>
The locked interface to acquire guest time by scheduling code
is introduced. It can be used by schedulers what do require
guest time from a different pcpu to take scheduling decission.
Signed-off-by: Andrii Anisov <andrii_anisov@epam.com>
---
xen/common/Kconfig | 3 +++
xen/common/schedule.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
xen/include/xen/sched.h | 11 +++++++++++
3 files changed, 58 insertions(+)
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 16829f6..c1748dd 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -221,6 +221,9 @@ config ARGO
menu "Schedulers"
visible if EXPERT = "y"
+config TACC_NEEDS_LOCK
+ bool
+
config SCHED_CREDIT
bool "Credit scheduler support"
default y
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index 62df77e..98b739f 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -1562,6 +1562,14 @@ static void schedule(void)
context_switch(prev, next);
}
+#ifdef CONFIG_TACC_NEEDS_LOCK
+#define tacc_lock(tacc) spin_lock(&tacc->tacc_lock)
+#define tacc_unlock(tacc) spin_unlock(&tacc->tacc_lock)
+#else
+#define tacc_lock(tacc)
+#define tacc_unlock(tacc)
+#endif
+
DEFINE_PER_CPU(struct tacc, tacc);
static void tacc_state_change(enum TACC_STATES new_state)
@@ -1571,6 +1579,7 @@ static void tacc_state_change(enum TACC_STATES new_state)
unsigned long flags;
local_irq_save(flags);
+ tacc_lock(tacc);
now = NOW();
delta = now - tacc->state_entry_time;
@@ -1584,6 +1593,7 @@ static void tacc_state_change(enum TACC_STATES new_state)
tacc->state = new_state;
tacc->state_entry_time = now;
+ tacc_unlock(tacc);
local_irq_restore(flags);
}
@@ -1621,7 +1631,9 @@ void tacc_irq_enter(int place)
if ( tacc->irq_cnt == 0 )
{
+ tacc_lock(tacc);
tacc->irq_enter_time = NOW();
+ tacc_unlock(tacc);
}
tacc->irq_cnt++;
@@ -1636,8 +1648,10 @@ void tacc_irq_exit(int place)
ASSERT(tacc->irq_cnt > 0);
if ( tacc->irq_cnt == 1 )
{
+ tacc_lock(tacc);
tacc->irq_time = NOW() - tacc->irq_enter_time;
tacc->irq_enter_time = 0;
+ tacc_unlock(tacc);
}
tacc->irq_cnt--;
@@ -1653,6 +1667,36 @@ s_time_t tacc_get_guest_time(struct tacc *tacc)
return guest_time;
}
+#ifdef CONFIG_TACC_NEEDS_LOCK
+s_time_t tacc_get_guest_time_cpu(int cpu)
+{
+ struct tacc* tacc = &per_cpu(tacc, cpu);
+ s_time_t guest_time;
+ s_time_t now;
+
+ tacc_lock(tacc);
+
+ now = NOW();
+ guest_time = tacc_get_guest_time(tacc);
+ if (tacc->state == TACC_GUEST || tacc->state == TACC_GSYNC)
+ {
+ guest_time += NOW() - tacc->state_entry_time;
+ }
+
+ if (tacc->irq_enter_time)
+ {
+ guest_time -= NOW() - tacc->irq_enter_time;
+ }
+
+ guest_time -= tacc->irq_time;
+
+ tacc_unlock(tacc);
+
+ return guest_time;
+}
+#endif
+
+
void context_saved(struct vcpu *prev)
{
/* Clear running flag /after/ writing context to memory. */
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 5b41805..a649d1f 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -1028,6 +1028,9 @@ struct tacc
s_time_t irq_enter_time;
s_time_t irq_time;
int irq_cnt;
+#ifdef CONFIG_TACC_NEEDS_LOCK
+ spinlock_t tacc_lock;
+#endif
};
DECLARE_PER_CPU(struct tacc, tacc);
@@ -1041,6 +1044,14 @@ inline s_time_t tacc_get_guest_time_delta(void)
return tacc_get_guest_time(&this_cpu(tacc)) - current->pcpu_guest_time;
}
+#ifdef CONFIG_TACC_NEEDS_LOCK
+s_time_t tacc_get_guest_time_cpu(int cpu);
+inline s_time_t tacc_get_guest_time_delta_vcpu(struct vcpu* vcpu)
+{
+ return tacc_get_guest_time_cpu(vcpu->processor) - vcpu->pcpu_guest_time;
+}
+#endif
+
#endif /* __SCHED_H__ */
/*
--
2.7.4
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-09-11 10:33 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-11 10:32 [Xen-devel] [RFC 0/9] Changes to time accounting Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 1/9] schedule: Introduce per-pcpu " Andrii Anisov
2019-09-11 18:01 ` Volodymyr Babchuk
2019-09-12 10:26 ` Andrii Anisov
2019-10-28 14:28 ` Julien Grall
2019-11-06 11:24 ` Andrii Anisov
2020-05-26 2:27 ` Volodymyr Babchuk
2020-05-29 8:48 ` Dario Faggioli
2020-06-02 1:12 ` Volodymyr Babchuk
2020-06-03 15:22 ` Dario Faggioli
2019-09-11 10:32 ` [Xen-devel] [RFC 2/9] sysctl: extend XEN_SYSCTL_getcpuinfo interface Andrii Anisov
2019-10-28 14:52 ` Julien Grall
2019-11-06 11:25 ` Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 3/9] xentop: show CPU load information Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 4/9] arm64: utilize time accounting Andrii Anisov
2019-09-11 17:48 ` Volodymyr Babchuk
2019-09-12 12:09 ` Andrii Anisov
2019-09-12 12:17 ` Julien Grall
2019-09-12 12:29 ` Andrii Anisov
2019-10-28 14:47 ` Julien Grall
2019-11-06 11:31 ` Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 5/9] tacc: Introduce a lockless interface for guest time Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 6/9] sched:rtds: get guest time from time accounting code Andrii Anisov
2019-09-11 10:32 ` Andrii Anisov [this message]
2019-09-11 10:32 ` [Xen-devel] [RFC 8/9] sched:credit: " Andrii Anisov
2019-09-11 10:32 ` [Xen-devel] [RFC 9/9] sched:credit2: " Andrii Anisov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1568197942-15374-8-git-send-email-andrii.anisov@gmail.com \
--to=andrii.anisov@gmail.com \
--cc=George.Dunlap@eu.citrix.com \
--cc=andrew.cooper3@citrix.com \
--cc=andrii_anisov@epam.com \
--cc=dfaggioli@suse.com \
--cc=ian.jackson@eu.citrix.com \
--cc=jbeulich@suse.com \
--cc=julien.grall@arm.com \
--cc=konrad.wilk@oracle.com \
--cc=sstabellini@kernel.org \
--cc=tim@xen.org \
--cc=wl@xen.org \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).