Bug 714053 - couple nice-to-have xen hypervisor patches
Summary: couple nice-to-have xen hypervisor patches
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel-xen
Version: 5.8
Hardware: x86_64
OS: Linux
unspecified
low
Target Milestone: rc
: ---
Assignee: Laszlo Ersek
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks: 514490
TreeView+ depends on / blocked
 
Reported: 2011-06-17 09:23 UTC by Andrew Jones
Modified: 2012-02-21 03:38 UTC (History)
7 users (show)

Fixed In Version: kernel-2.6.18-284.el5
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2012-02-21 03:38:19 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)
[PATCH] xen: double debug ring buffer size (533 bytes, patch)
2011-06-17 09:33 UTC, Andrew Jones
no flags Details | Diff
[PATCH] xen: always set nr_cpus to 256 for x86_64 builds (354 bytes, patch)
2011-06-17 09:34 UTC, Andrew Jones
no flags Details | Diff
[PATCH] xen: get rid of debug log spam (738 bytes, patch)
2011-06-17 09:34 UTC, Andrew Jones
no flags Details | Diff
bump default NR_CPUS to 256 on x86_64; get rid of debug log spam (1.41 KB, patch)
2011-08-29 10:55 UTC, Laszlo Ersek
no flags Details | Diff


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2012:0150 0 normal SHIPPED_LIVE Moderate: Red Hat Enterprise Linux 5.8 kernel update 2012-02-21 07:35:24 UTC

Description Andrew Jones 2011-06-17 09:23:48 UTC
Attached are a couple patches that would be nice to drop into xen. I wouldn't be overly heart broken if we just close this bug as wont-fix, but I think these are at least worth discussing, so I'm writing the bug in case we decide to post them.

Feel free to add more...

Comment 1 Andrew Jones 2011-06-17 09:33:58 UTC
Created attachment 505218 [details]
[PATCH] xen: double debug ring buffer size


16k is too small to be useful. xend python code already supports 32k.
Unfortunately xenconsoled is also set at 16k and needs to be updated
to support this change.
---
 drivers/char/console.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Comment 2 Andrew Jones 2011-06-17 09:34:08 UTC
Created attachment 505219 [details]
[PATCH] xen: always set nr_cpus to 256 for x86_64 builds


Developers generally just type 'make' to build test hypervisors. This
patch makes sure they always get NR_CPUS set to 256 for x86_64 builds,
otherwise the test hypervisor would only have 32 and may not test things
correctly.
---
 include/asm-x86/config.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

Comment 3 Andrew Jones 2011-06-17 09:34:17 UTC
Created attachment 505220 [details]
[PATCH] xen: get rid of debug log spam


This message is useless and spams the logs when debug messages are
turned on. Just get rid of it.
---
 common/sysctl.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

Comment 4 Andrew Jones 2011-06-17 09:46:07 UTC
(In reply to comment #1)
> Unfortunately xenconsoled is also set at 16k and needs to be updated
> to support this change.

The xenconsoled change would be here in console/daemon/io.c

782 static void handle_hv_logs(void)
783 {
784         char buffer[1024*16];

Comment 5 Paolo Bonzini 2011-07-14 12:33:47 UTC
I agree about the last two patches.  For the first, it is risky (what about updates to kernel-xen before xen?) and anyway any fixed value is useless.  To work properly with debug output you need a serial console. :(

Comment 6 Laszlo Ersek 2011-08-29 10:55:45 UTC
Created attachment 520346 [details]
bump default NR_CPUS to 256 on x86_64; get rid of debug log spam

not doubling xm dmesg ringbuf size as per comment 5

I built an x86_64 binary locally, without explicitly passing max_phys_cpus=256 as usual.

Tested on my workstation with virt-manager, the debug log spam disappeared when compared to -281.

Tested on "dell-per815-02.lab.bos.redhat.com" with "xm info", "nr_cpus" is "48".

Brew in progress: https://brewweb.devel.redhat.com/taskinfo?taskID=3588923

Comment 7 Laszlo Ersek 2011-08-29 10:59:38 UTC
(In reply to comment #6)
> Created attachment 520346 [details]
> bump default NR_CPUS to 256 on x86_64; get rid of debug log spam

NR_CPUS change mailed to upstream:

http://lists.xensource.com/archives/html/xen-devel/2011-08/msg01208.html

Comment 9 RHEL Program Management 2011-08-29 11:10:11 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 11 Jarod Wilson 2011-09-02 15:39:40 UTC
Patch(es) available in kernel-2.6.18-284.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5
Detailed testing feedback is always welcomed.

Comment 12 Jarod Wilson 2011-09-02 17:41:30 UTC
Patch(es) available in kernel-2.6.18-284.el5
You can download this test kernel (or newer) from http://people.redhat.com/jwilson/el5
Detailed testing feedback is always welcomed.

Comment 14 Qixiang Wan 2011-12-27 03:10:32 UTC
https://bugzilla.redhat.com/show_bug.cgi?id=714053

Verified with kernel-xen-2.6.18-300.el5.

Before the fix, I built a x86_64 hypervisor (no max_phys_cpus specified), then boot up the hypervisor on a host with 64 cpus, xm info show nr_cpus = 32. After the fix, the xm info show correct number of cpus.

And before the fix, there are messages of "(XEN) sysctl.c:51: Allowing physinfo call with newer ABI version" printed in xm dmesg when virt-manager start. After the fix, there is no such message anymore.

Comment 15 errata-xmlrpc 2012-02-21 03:38:19 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2012-0150.html


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