9. EAL parameters
This document contains a list of all EAL parameters. These parameters can be used by any DPDK application running on Linux.
9.1. Common EAL parameters
The following EAL parameters are common to all platforms supported by DPDK.
9.1.5. Debugging options
--no-shconf
No shared files created (implies no secondary process support).
--no-huge
Use anonymous memory instead of hugepages (implies no secondary process support).
--log-level <type:val>
Specify log level for a specific component. For example:
--log-level lib.eal:debug
Can be specified multiple times.
--trace=<regex-match>
Enable trace based on regular expression trace name. By default, the trace is disabled. User must specify this option to enable trace. For example:
Global trace configuration for EAL only:
--trace=eal
Global trace configuration for ALL the components:
--trace=.*
Can be specified multiple times up to 32 times.
--trace-dir=<directory path>
Specify trace directory for trace output. For example:
Configuring
/tmp/
as a trace output directory:--trace-dir=/tmp
By default, trace output will created at
home
directory and parameter must be specified once only.--trace-bufsz=<val>
Specify maximum size of allocated memory for trace output for each thread. Valid unit can be either
B
orK
orM
forBytes
,KBytes
andMBytes
respectively. For example:Configuring
2MB
as a maximum size for trace output file:--trace-bufsz=2M
By default, size of trace output file is
1MB
and parameter must be specified once only.--trace-mode=<o[verwrite] | d[iscard] >
Specify the mode of update of trace output file. Either update on a file can be wrapped or discarded when file size reaches its maximum limit. For example:
To
discard
update on trace output file:--trace-mode=d or --trace-mode=discard
Default mode is
overwrite
and parameter must be specified once only.
9.1.6. Other options
-h
,--help
Display help message listing all EAL parameters.
-v
Display the version information on startup.
--mbuf-pool-ops-name
:Pool ops name for mbuf to use.
--telemetry
:
Enable telemetry (enabled by default).
--no-telemetry
:
Disable telemetry.
--force-max-simd-bitwidth=<val>
:
Specify the maximum SIMD bitwidth size to handle. This limits which vector paths, if any, are taken, as any paths taken must use a bitwidth below the max bitwidth limit. For example, to allow all SIMD bitwidths up to and including AVX-512:
--force-max-simd-bitwidth=512The following example shows limiting the bitwidth to 64-bits to disable all vector code:
--force-max-simd-bitwidth=64To disable use of max SIMD bitwidth limit:
--force-max-simd-bitwidth=0
9.2. Linux-specific EAL parameters
In addition to common EAL parameters, there are also Linux-specific EAL parameters.
9.2.1. Device-related options
--create-uio-dev
Create
/dev/uioX
files for devices bound to igb_uio kernel driver (usually done by the igb_uio driver itself).--vmware-tsc-map
Use VMware TSC map instead of native RDTSC.
--no-hpet
Do not use the HPET timer.
--vfio-intr <legacy|msi|msix>
Use specified interrupt mode for devices bound to VFIO kernel driver.
--vfio-vf-token <uuid>
Use specified VF token for devices bound to VFIO kernel driver.
9.2.2. Multiprocessing-related options
--file-prefix <prefix name>
Use a different shared data file prefix for a DPDK process. This option allows running multiple independent DPDK primary/secondary processes under different prefixes.
9.2.3. Memory-related options
--legacy-mem
Use legacy DPDK memory allocation mode.
--socket-mem <amounts of memory per socket>
Preallocate specified amounts of memory per socket. The parameter is a comma-separated list of values. For example:
--socket-mem 1024,2048
This will allocate 1 gigabyte of memory on socket 0, and 2048 megabytes of memory on socket 1.
--socket-limit <amounts of memory per socket>
Place a per-socket upper limit on memory use (non-legacy memory mode only). 0 will disable the limit for a particular socket.
--single-file-segments
Create fewer files in hugetlbfs (non-legacy mode only).
--huge-dir <path to hugetlbfs directory>
Use specified hugetlbfs directory instead of autodetected ones. This can be a sub-directory within a hugetlbfs mountpoint.
--huge-unlink[=existing|always|never]
No
--huge-unlink
option or--huge-unlink=existing
is the default: existing hugepage files are removed and re-created to ensure the kernel clears the memory and prevents any data leaks.With
--huge-unlink
(no value) or--huge-unlink=always
, hugepage files are also removed before mapping them, so that the application leaves no files in hugetlbfs. This mode implies no multi-process support.When
--huge-unlink=never
is specified, existing hugepage files are never removed, but are remapped instead, allowing hugepage reuse. This makes restart faster by saving time to clear memory at initialization, but it may slow down zeroed allocations later. Reused hugepages can contain data from previous processes that used them, which may be a security concern. Hugepage files created in this mode are also not removed when all the hugepages mapped from them are freed, which allows to reuse these files after a restart.--match-allocations
Free hugepages back to system exactly as they were originally allocated.
9.2.4. Other options
--syslog <syslog facility>
Set syslog facility. Valid syslog facilities are:
auth cron daemon ftp kern lpr mail news syslog user uucp local0 local1 local2 local3 local4 local5 local6 local7