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[Qemu-devel] [PATCH v3 0/6] prevent Qemu from waking up needlessly
From: |
Stefano Stabellini |
Subject: |
[Qemu-devel] [PATCH v3 0/6] prevent Qemu from waking up needlessly |
Date: |
Fri, 27 Jan 2012 18:20:16 +0000 |
User-agent: |
Alpine 2.00 (DEB 1167 2008-08-23) |
Hi all,
this small patch series prevents Qemu from waking up needlessly on Xen
several times a second in order to check some timers.
The first patch stops Qemu from emulating the PIT on Xen, the second
patch disables the rtc_clock entirely.
The third patch makes use of a new mechanism to receive buffered io
event notifications from Xen, so that Qemu doesn't need to check the
buffered io page for data 10 times a sec for the entire life of the VM.
The fourth patch fixes win32_rearm_timer and mm_rearm_timer that
risk an overflow if INT64_MAX is passed as delta.
The fifth patch changes qemu_next_alarm_deadline only to check the
expire time of a clock if it is enabled.
Finally the last patch increases the default select timeout to 1h:
nothing should rely on the select timeout to be 1sec, so we might as
well increase it to 1h.
Changes in v3:
- added a new patch to fix win32_rearm_timer and mm_rearm_timer, that
risk an overflow if INT64_MAX is passed as delta.
Shortlog and diffstat follow:
Stefano Stabellini (6):
xen: do not initialize the interval timer emulator
xen: disable rtc_clock
xen: introduce an event channel for buffered io event notifications
timers: the rearm function should be able to handle delta = INT64_MAX
qemu_next_alarm_deadline: check the expire time of a clock only if it is
enabled
qemu_calculate_timeout: increase minimum timeout to 1h
hw/pc.c | 7 +++++--
qemu-timer.c | 30 ++++++++++++++++++------------
xen-all.c | 43 +++++++++++++++++++++++++++++++++++++------
3 files changed, 60 insertions(+), 20 deletions(-)
A git tree available here:
git://xenbits.xen.org/people/sstabellini/qemu-dm.git timers-3
Cheers,
Stefano