Irqbalance - Revision history

Leo: /* Interrupts overloading a single CPU */

2022-06-25T16:13:23Z

Interrupts overloading a single CPU

← Older revision		Revision as of 16:13, 25 June 2022
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	## To ignore inactive interrupts		## To ignore inactive interrupts
	$ watch -d -n 1 "cat /proc/interrupts {{!}} grep -vE '^\s[0-9]+:[ 0] [A-Za-Z]+'"		$ watch -d -n 1 "cat /proc/interrupts {{!}} grep -vE '^\s[0-9]+:[ 0] [A-Za-z]+'"
	\| lang = terminal		\| lang = terminal
	}}		}}

Leo: Added categories and navbox

2021-12-30T01:06:21Z

Added categories and navbox

← Older revision		Revision as of 01:06, 30 December 2021
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	If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.		If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.
			{{Navbox Linux}}
			[[Category:Linux]]
			[[Category:LinuxUtilities]]

Leo at 01:44, 16 November 2021

2021-11-16T01:44:11Z

@@ Line 14: / Line 14: @@
 ===Under the hood===
 What irqbalance does is it reads <code>/proc/interrupts</code> and determines the IRQ sources. It then tries to balance out the IRQs across all CPU cores by setting the appropriate CPU affinity flags under <code>/proc/irq/<irq>/smp_affinity</code>.
 If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.

Leo: /* Interrupts overloading a single CPU */

2021-11-16T01:39:17Z

Interrupts overloading a single CPU

← Older revision		Revision as of 01:39, 16 November 2021
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	irqbalance is a utility that helps balance interrupts across all available CPUs on a system. The tool does the balancing by setting the appropriate CPU affinities for each IRQ source.		irqbalance is a utility that helps balance interrupts across all available CPUs on a system. The tool does the balancing by setting the appropriate CPU affinities for each IRQ source.

	=== Interrupts overloading a single CPU ===		===Interrupts overloading a single CPU===
	Without irqbalance, you might see a single ksoftirqd process running with a high CPU utilization. On a busy system, you might see this stuck at 100% CPU. To confirm what's happening, run:		Without irqbalance, you might see a single ksoftirqd process running with a high CPU utilization. On a busy system, you might see this stuck at 100% CPU. To confirm what's happening, run:
	{{Highlight		{{Highlight
	\| code = $ watch -d -n 1 "cat /proc/interrupts"		\| code = $ watch -d -n 1 "cat /proc/interrupts"

			## To ignore inactive interrupts
			$ watch -d -n 1 "cat /proc/interrupts {{!}} grep -vE '^\s[0-9]+:[ 0] [A-Za-Z]+'"
	\| lang = terminal		\| lang = terminal
	}}		}}
	Using <code>watch</code> and the <code>--diff</code> option, you can see how fast the number of interrupts are increasing for each IRQ source. If you see large numbers within a single column, you should try running irqbalance to help balance out the IRQ sources across multiple CPU cores.		Using <code>watch</code> and the <code>--diff</code> option, you can see how fast the number of interrupts are increasing for each IRQ source. If you see large numbers within a single column, you should try running irqbalance to help balance out the IRQ sources across multiple CPU cores.

	=== Under the hood ===		===Under the hood===
	What irqbalance does is it reads <code>/proc/interrupts</code> and determines the IRQ sources. It then tries to balance out the IRQs across all CPU cores by setting the appropriate CPU affinity flags under <code>/proc/irq/<irq>/smp_affinity</code>.		What irqbalance does is it reads <code>/proc/interrupts</code> and determines the IRQ sources. It then tries to balance out the IRQs across all CPU cores by setting the appropriate CPU affinity flags under <code>/proc/irq/<irq>/smp_affinity</code>.

	If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.		If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.

Leo: Created page with "irqbalance is a utility that helps balance interrupts across all available CPUs on a system. The tool does the balancing by setting the appropriate CPU affinities for each IRQ..."

2021-11-16T01:33:18Z

Created page with "irqbalance is a utility that helps balance interrupts across all available CPUs on a system. The tool does the balancing by setting the appropriate CPU affinities for each IRQ..."

New page

irqbalance is a utility that helps balance interrupts across all available CPUs on a system. The tool does the balancing by setting the appropriate CPU affinities for each IRQ source.

=== Interrupts overloading a single CPU ===
Without irqbalance, you might see a single ksoftirqd process running with a high CPU utilization. On a busy system, you might see this stuck at 100% CPU. To confirm what's happening, run:
{{Highlight
| code = $ watch -d -n 1 "cat /proc/interrupts"
| lang = terminal
}}
Using <code>watch</code> and the <code>--diff</code> option, you can see how fast the number of interrupts are increasing for each IRQ source. If you see large numbers within a single column, you should try running irqbalance to help balance out the IRQ sources across multiple CPU cores.

=== Under the hood ===
What irqbalance does is it reads <code>/proc/interrupts</code> and determines the IRQ sources. It then tries to balance out the IRQs across all CPU cores by setting the appropriate CPU affinity flags under <code>/proc/irq/<irq>/smp_affinity</code>.

If you need to manually balance out IRQs, you can turn off irqbalance and tweak the smp affinities yourself.