FS#11791 - [kernel26] Please disable CONFIG_IRQBALANCE

Attached to Project: Arch Linux
Opened by Swift Geek (swiftgeek) - Friday, 17 October 2008, 23:08 GMT
Last edited by Tobias Powalowski (tpowa) - Sunday, 26 October 2008, 20:40 GMT
Task Type Feature Request
Category Kernel
Status Closed
Assigned To Tobias Powalowski (tpowa)
Thomas Bächler (brain0)
Architecture All
Severity Low
Priority Normal
Reported Version None
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 3
Private No

Details

Please disable CONFIG_IRQBALANCE in kernel config
PowerTOP:
"Suggestion: Disable the CONFIG_IRQBALANCE kernel configuration option.
The in-kernel irq balancer is obsolete and wakes the CPU up far more than needed."
This task depends upon

Closed by  Tobias Powalowski (tpowa)
Sunday, 26 October 2008, 20:40 GMT
Reason for closing:  Fixed
Comment by Lothar Gesslein (ulmen) - Monday, 20 October 2008, 07:45 GMT
And this is not just recommended by the PowerTOP author, but by the Kernel Maintainers. Here is the corresponding Commit Message:



Mark CONFIG_IRQBALANCE as not recommended any more. It eats too much
power, and better solutions are available in userspace.

Signed-off-by: Pavel Machek <pavel@suse.cz>

---
commit 2665f7971b5b97830b028308553a78a95c131988
tree e1782cceebfb5900373469c0043d113de88f861f
parent f5085f6ea1c5771708c44a4a42ee217e760ff4a0
author Pavel <pavel@amd.ucw.cz> Tue, 23 Oct 2007 13:56:15 +0200
committer Pavel <pavel@amd.ucw.cz> Tue, 23 Oct 2007 13:56:15 +0200

arch/i386/Kconfig | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index eba2d88..10f3c38 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -779,10 +779,13 @@ config EFI
config IRQBALANCE
bool "Enable kernel irq balancing"
depends on SMP && X86_IO_APIC
- default y
+ default n
help
- The default yes will allow the kernel to do irq load balancing.
- Saying no will keep the kernel from doing irq load balancing.
+ Saying yes will allow the kernel to do irq load balancing;
+ but it generates too many CPU wakeups, eating power, and
+ is better done in userspace.
+
+ Say N.

# turning this on wastes a bunch of space.
# Summit needs it only when NUMA is on
Comment by Alberto Gonzalez (Luis) - Thursday, 23 October 2008, 19:22 GMT
I support this request. The userspace daemon is the recommended utility for this task. It is now in AUR (unsupported), so maybe promoting it to at least the community repo if possible would be a good way to solve this issue.
Comment by Dan McGee (toofishes) - Friday, 24 October 2008, 06:49 GMT
This code isn't even in the kernel anymore- it has been removed. We should definitely disable this.
Comment by Dan McGee (toofishes) - Friday, 24 October 2008, 22:41 GMT
Note that I added the "irqbalance" package to extra yesterday for both architectures.

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