intctl.1m (2010 09)

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intctl(1M) intctl(1M)

NAME

intctl - manage the interrupt conﬁguration of the system

SYNOPSIS

/usr/sbin/intctl

[-h | -F | -p | -c cpu_id ]

/usr/sbin/intctl

[-C class ][-H hw_path ]

/usr/sbin/intctl

[-M -H hw_path -I intr_id -c

cpu_id [-w]]

/usr/sbin/intctl

[-M -H hw_path -f ﬁle [

-w]]

/usr/sbin/intctl

[-r ﬁle | -s ﬁle]

/usr/sbin/intctl

[-l [cell_id ]]

/usr/sbin/intctl

[-b [-w][-a algorithm ]

[

-i io:hw_path:intr_id]...

[-i cpu:hw_path]...

[-i drv:driver_name]...

[-o drv:driver_name:weight]...

[-o trig:balance_on_cpu:distribute_to_cpu

]...]

DESCRIPTION

A processor receives an interrupt in one or more of these occurrences:

• When the processor’s interrupt pin is asserted (for line based interrupts).

• If a processor detects an interrupt message bus transaction on the system bus (for transaction based

interrupts).

Interrupts from the interface cards can be line or transaction based. Interrupts are routed to different

processors during boot time.

The

intctl command is a tool that allows a performance expert to display and modify these interrupt

assignments. The tool only supports migration of external device interrupts. The performance analyst

can also save and restore the interrupt conﬁguration. If interrupt migration process completes success-

fully, a message is logged to the console and/or to the /var/adm/syslog/syslog.log

ﬁle.

intctl resides in /usr/sbin/bin

(a symbolic link exists in /usr/contrib/bin), and the com-

mand can be executed only by the superuser. The

intctl command is not a general system administra-

tion command. It should be used only by performance tuning experts with a high level of system

knowledge. The performance specialist can use the intctl command to view the interrupt

conﬁguration of the system and modify the interrupt assignments of the CPUs to re-distribute the system

load across the CPUs.

intctl is synchronized with other High Availability (HA) events happening simultaneously on the sys-

tem. An HA event can be a PCI OLA/R or Processor allocation/de-allocation. If any of these events are

happening when intctl is trying to display interrupt information or is trying to migrate an interrupt to

a CPU, intctl exits with the error message below, and the user should retry the intctl command:

"Another HA event is in progress, try again!"

Non-MP safe drivers do not support interrupt migration. The intctl command displays an error mes-

sage if the user tries to move the interrupts of a non-MP safe driver to a different CPU.

On a system with virtual partitions (vPars),

intctl displays only CPUs in the current partition.

Using the

-b option, the intctl command balances the interrupt distribution on a system. Interrupt

assignments to CPUs on a given system are not always distributed in a balanced manner. Most of the

time, imbalance in distribution is caused by CPU migrations. These migrations may cause the interrupts

to get assigned to CPUs available in the system in a non-optimal fashion and the interrupts are not redis-

tributed when more CPUs become available. In such a scenario, the -b option of the intctl command

can be used to balance the interrupt distribution on the system.

By default, HP-UX distributes interrupts at boot time using a "round robin" allocation method. In this

method, the ﬁrst interrupt is assigned to the ﬁrst available CPU. Then the next interrupt is assigned to

the next available CPU and these assignments continue. After all the CPUs have been assigned, the

interrupt assignment starts from the ﬁrst CPU again.

CPU migrations can occur because of Work Load Manager (WLM) conﬁguration, vPars administration

activity, and/or Instant Capacity (iCAP/TiCAP) administration activity. These migrations can cause the

HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1

Summary of content (10 pages)

PAGE 1
intctl(1M) intctl(1M) NAME intctl - manage the interrupt configuration of the system SYNOPSIS /usr/sbin/intctl [-h | -F | -p | -c cpu_id ] /usr/sbin/intctl [-C class ] [-H hw_path ] /usr/sbin/intctl [-M -H hw_path -I intr_id -c cpu_id [-w]] /usr/sbin/intctl [-M -H hw_path -f file [-w]] /usr/sbin/intctl [-r file | -s file ] /usr/sbin/intctl [-l [cell_id ]] /usr/sbin/intctl [-b [-w] [-a algorithm ] [-i io:hw_path:intr_id]... [-i cpu:hw_path]... [-i drv:driver_name ]... [-o drv:driver_name:weight]...
PAGE 2
intctl(1M) intctl(1M) interrupts to be assigned to a smaller set of CPUs causing an imbalance and thus a non-optimally configured system. Using the -b option allows the user to manually balance the interrupt distribution of the system. Users can choose one of these two balancing algorithms to balance interrupts: • driver_weight The default balancing algorithm used by intctl is driver_weight. This balancing algorithm associates weights to each driver based on its interrupt frequency.
PAGE 3
intctl(1M) intctl(1M) If the -w option is not specified, the user then has the choice to confirm or skip all migrations or selectively pick only a few migrations. If the -w option is also specified, no confirmation message is displayed. -c cpu_id By itself (without any other options), the -c option displays interrupt information about the specified CPU cpu_id . When used with the -M option, -c cpu_id specifies the CPU ID of the CPU to which the interrupt is to be moved.
PAGE 4
intctl(1M) intctl(1M) configuration file. NOTE: Refer to the INTCTL_DRV_IGNORE section of the /etc/intctl.conf configuration file for other drivers that are currently not supported while balancing interrupts. Refer also to the Interrupt Configuration Display and Interrupt Configuration File sections of this manpage for more interrupt configuration information. A -I intr_id Specify the interrupt ID of the interrupt to be moved or migrated (to be used with the -M option).
PAGE 5
intctl(1M) -r file intctl(1M) Restore the system interrupt configuration from the specified file, file . The interrupt configuration is restored only if all the interface cards and CPUs referenced in the saved configuration file are still present on the system and the CPUs are in the same state as in the saved configuration. If new cards and new CPUs are added to the system, intctl will continue to restore the interrupt configuration as long as the old configuration has not changed.
PAGE 6
intctl(1M) intctl(1M) cpu cell The cell number of the cell to which the CPU is connected. intr type A character representing the interrupt type: L T M X line based interrupt transaction based interrupt MSI based interrupt MSI-X based interrupt The identity of the interrupt to be moved. intr ID card description A brief description of the interface card. A cpu path The hardware path of the CPU (relevant with the -s and -r options).
PAGE 7
intctl(1M) intctl(1M) The following descriptions explain each column in the table: Sl. Num. Serial number (starting from 1) of all the migrations that will be performed for balancing of interrupts. These serial numbers can be used in selecting migrations that have to be skipped. Card H/W Path The hardware path of I/O cards whose interrupt is getting migrated. Driver name The driver associated with the card. Intr ID The identity of the interrupt to be moved.
PAGE 8
intctl(1M) intctl(1M) Example: INTCTL_DRIVER_WEIGHTS graf 300 2. INTCTL_HW_IGNORE Each line after the above string is expected to be of the form hw_path intr_id . hw_path is a string corresponding to the hardware path of the I/O card and intr_id is an integer corresponding to the interrupt ID. The specified I/O card and the interrupt ID combination is ignored (that is, will not be migrated) while balancing interrupts.
PAGE 9
intctl(1M) intctl(1M) NOTE: Refer to this section of the configuration file for drivers that are currently not supported while balancing interrupts. 5. INTCTL_DEFAULT_ALGO The line that follows INTCTL_DEFAULT_ALGO specifies the default algorithm to be used while balancing interrupts (when -a is not used). The supported algorithms are driver_weight and round_robin. The -a algorithm option can be used to change the algorithm temporarily. Example: INTCTL_DEFAULT_ALGO driver_weight 6.
PAGE 10
intctl(1M) intctl(1M) Migrate the interrupt with ID 1, coming from the card whose hardware path is 0/4/0/0/5/0 to CPU 3: intctl -M -H 0/4/0/0/5/0 -I 1 -c 3 Migrate interrupts of the card whose hardware path is 0/4/0/1 as specified by the entries in the file intr_assign.