From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xen.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [PATCH RFC v2 0/2] Fix RTC noack issues
Date: Thu, 5 Dec 2013 11:09:06 +0000 [thread overview]
Message-ID: <1386241748-9617-1-git-send-email-andrew.cooper3@citrix.com> (raw)
This series allows the toolstack to choose (by way of XenStore platform flags)
whether the domain is expecting to make use of RTC mode noack performance
optimisations.
It also switches the implict default back to rtc_mode_strict, which is the
safe default for Xen to have.
This fixes a longstanding regression in Win2k3SP2 only where its access
pattern causes it to fall into an infinite loop reading RTC RegC.
Questions for thought:
* Does it make sense to allow customisation of ACPI_WAET_TIMER_ONE_READ ?
There is no sitation where an admin should turn it off.
* I believe this is safe wrt migrations, but am not certain enough to say for
sure. This is a critical point, as the bad default (and regression) has
been in Xen since late in the Xen-4.3 development cycle.
---
Changes in v2:
* Remove the hypervisor enum and replace with a formal ABI in params.h
* Leave PM timer reads alone and accept fewer options for "true"
--
1.7.10.4
next reply other threads:[~2013-12-05 11:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-05 11:09 Andrew Cooper [this message]
2013-12-05 11:09 ` [Patch v2 1/2] x86/vRTC: Make rtc_mode_{strict, no_ack} a per-domain option Andrew Cooper
2013-12-05 11:09 ` [Patch v2 2/2] hvmloader: Allow the toolstack to choose WAET optimisations Andrew Cooper
2013-12-05 15:38 ` Keir Fraser
2013-12-06 9:43 ` Jan Beulich
2013-12-06 9:37 ` [PATCH RFC v2 0/2] Fix RTC noack issues Jan Beulich
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=1386241748-9617-1-git-send-email-andrew.cooper3@citrix.com \
--to=andrew.cooper3@citrix.com \
--cc=xen-devel@lists.xen.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).