From: Anchal Agarwal <anchalag@amazon.com>
To: <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
<hpa@zytor.com>, <x86@kernel.org>, <boris.ostrovsky@oracle.com>,
<jgross@suse.com>, <linux-pm@vger.kernel.org>,
<linux-mm@kvack.org>, <kamatam@amazon.com>,
<sstabellini@kernel.org>, <konrad.wilk@oracle.com>,
<roger.pau@citrix.com>, <axboe@kernel.dk>, <davem@davemloft.net>,
<rjw@rjwysocki.net>, <len.brown@intel.com>, <pavel@ucw.cz>,
<peterz@infradead.org>, <eduval@amazon.com>, <sblbir@amazon.com>,
<anchalag@amazon.com>, <xen-devel@lists.xenproject.org>,
<vkuznets@redhat.com>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <dwmw@amazon.co.uk>,
<fllinden@amaozn.com>, <benh@kernel.crashing.org>
Subject: [Xen-devel] [RFC PATCH v3 10/12] xen: Introduce wrapper for save/restore sched clock offset
Date: Wed, 12 Feb 2020 22:34:39 +0000 [thread overview]
Message-ID: <20200212223439.GA4444@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> (raw)
Introduce wrappers for save/restore xen_sched_clock_offset to be
used by PM hibernation code to avoid system instability during resume.
Signed-off-by: Anchal Agarwal <anchalag@amazon.com>
---
Changes since V2:
* Dropped marking tsc unstable during hibernation patch
* Fixed issue with xen_sched_clock_offset during suspend/resume
* On further interrogation and testing, the issue wasn't with tsc
being stable/unstable
---
arch/x86/xen/time.c | 15 +++++++++++++--
arch/x86/xen/xen-ops.h | 2 ++
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 8cf632dda605..eeb6d3d2eaab 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -379,12 +379,23 @@ static const struct pv_time_ops xen_time_ops __initconst = {
static struct pvclock_vsyscall_time_info *xen_clock __read_mostly;
static u64 xen_clock_value_saved;
+/*This is needed to maintain a monotonic clock value during PM hibernation */
+void xen_save_sched_clock_offset(void)
+{
+ xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset;
+}
+
+void xen_restore_sched_clock_offset(void)
+{
+ xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved;
+}
+
void xen_save_time_memory_area(void)
{
struct vcpu_register_time_memory_area t;
int ret;
- xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset;
+ xen_save_sched_clock_offset();
if (!xen_clock)
return;
@@ -426,7 +437,7 @@ void xen_restore_time_memory_area(void)
out:
/* Need pvclock_resume() before using xen_clocksource_read(). */
pvclock_resume();
- xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved;
+ xen_restore_sched_clock_offset();
}
static void xen_setup_vsyscall_time_info(void)
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index d84c357994bd..9f49124df033 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -72,6 +72,8 @@ void xen_save_time_memory_area(void);
void xen_restore_time_memory_area(void);
void xen_init_time_ops(void);
void xen_hvm_init_time_ops(void);
+void xen_save_sched_clock_offset(void);
+void xen_restore_sched_clock_offset(void);
irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
--
2.24.1.AMZN
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next reply other threads:[~2020-02-12 22:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 22:34 Anchal Agarwal [this message]
2020-02-14 23:21 [Xen-devel] [RFC RESEND PATCH v3 00/12] Enable PM hibernation on guest VMs Anchal Agarwal
2020-02-14 23:27 ` [Xen-devel] [RFC PATCH v3 10/12] xen: Introduce wrapper for save/restore sched clock offset Anchal Agarwal
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=20200212223439.GA4444@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com \
--to=anchalag@amazon.com \
--cc=axboe@kernel.dk \
--cc=benh@kernel.crashing.org \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@alien8.de \
--cc=davem@davemloft.net \
--cc=dwmw@amazon.co.uk \
--cc=eduval@amazon.com \
--cc=fllinden@amaozn.com \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=kamatam@amazon.com \
--cc=konrad.wilk@oracle.com \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=peterz@infradead.org \
--cc=rjw@rjwysocki.net \
--cc=roger.pau@citrix.com \
--cc=sblbir@amazon.com \
--cc=sstabellini@kernel.org \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=x86@kernel.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).