Chapter 2. Optimizing system performance with TuneD

assertion

Compare two arguments. If they do not match, the function logs text from the first argument and cancels profile loading.

assertion_non_equal

Compare two arguments. If they match, the function logs text from the first argument and cancels profile loading.

calc_isolated_cores

Calculates and returns isolated cores. The argument specifies how many cores per socket to reserve for housekeeping. If not specified, one core per socket is reserved for housekeeping and the rest are isolated.

check_net_queue_count

Checks whether the user has specified a queue count for net devices. If not, it returns the number of housekeeping CPUs.

cpuinfo_check

Checks regular expressions against /proc/cpuinfo. Accepts arguments in the form: REGEX1, STR1, REGEX2, STR2, …​[, STR_FALLBACK]. If REGEX1 matches something in /proc/cpuinfo, it expands to STR1; if REGEX2 matches, it expands to STR2. It stops on the first match. If no regular expression matches, it expands to STR_FALLBACK or an empty string if no fallback is provided.

cpulist2devs

Converts a CPU list to device strings.

cpulist2hex

Converts a CPU list to a hexadecimal CPU mask.

cpulist2hex_invert

Converts a CPU list to a hexadecimal CPU mask and inverts it.

cpulist_invert

Inverts a list of CPUs to make its complement. For example, on a system with 4 CPUs (0-3), the inversion of the list 0,2,3 is 1.

cpulist_online

Checks whether the CPUs from the list are online. Returns the list containing only online CPUs.

cpulist_pack

Packs a CPU list in the form of 1,2,3,5 to 1-3,5.

cpulist_present

Checks whether the CPUs from the list are present. Returns the list containing only present CPUs.

cpulist_unpack

Unpacks a CPU list in the form of 1-3,4 to 1,2,3,4.

exec

Executes a process and returns its output.

hex2cpulist

Converts a hexadecimal CPU mask to a CPU list.

intel_recommended_pstate

Checks the processor code name and returns the recommended intel_pstate CPUFreq driver mode. "Active" is returned for newer generation processors not in the PROCESSOR_NAME list.

iscpu_check

Checks regular expressions against the output of iscpu. Accepts arguments in the form: REGEX1, STR1, REGEX2, STR2, …​[, STR_FALLBACK]. If REGEX1 matches something in the output, it expands to STR1; if REGEX2 matches, it expands to STR2. It stops on the first match. If no regular expression matches, it expands to STR_FALLBACK or an empty string if no fallback is provided.

package2cpus

Provides a CPU device list for a package (socket).

package2uncores

Provides an uncore device list for a package (socket).

regex_search_ternary

Ternary regular expression operator. Takes arguments in the form: STR1, REGEX, STR2, STR3. If REGEX matches STR1 (re.search is used), STR2 is returned; otherwise, STR3 is returned.

log

Expands to the concatenation of arguments and logs the result, useful for debugging.

kb2s

Converts KB to disk sectors.

s2kb

Converts disk sectors to KB.

strip

Creates a string from all passed arguments and deletes both leading and trailing white spaces.

virt_check

Checks whether TuneD is running inside a virtual machine (VM) or on bare metal. Inside a VM, the function returns the first argument. On bare metal, the function returns the second argument, even in case of an error.