Viewing: ldlm.namespaces.contention_events.4
.TH LDLM.NAMESPACES.CONTENTION_EVENTS 4 2026-04-28 Lustre "Lustre Kernel Interfaces"
.SH NAME
ldlm.namespaces.contention_events \- LDLM lock contention detection counter
.SH SYNOPSIS
.SY "lctl get_param"
.BI ldlm.namespaces.filter- FSNAME-* .contention_events
.SY "lctl set_param"
.BI ldlm.namespaces.filter- FSNAME-* .contention_events= 0
.YS
.SS PROPERTIES
.TP
.B Perms
.BR 644 " | " -rw-r--r--
.br
Writing to this parameter resets the counter
.TP
.B Scope
Per OST filter (OSS) namespace only
.TP
.B Config
present on OSS nodes
.TP
.B Default
.RB ldlm.namespaces.filter-*.contention_events= 0
.SH DESCRIPTION
.B ldlm.namespaces.filter-*.contention_events
counts conflicting lock requests observed in the specified namespace while
a resource is in the contended state.
.PP
The detector tracks conflicting lock activity for each resource over the
.B ldlm.namespaces.filter-*.contention_seconds
time window. When the amount of conflicting activity is more than the
.B ldlm.namespaces.filter-*.contended_locks
threshold, the resource is treated as contended for
.B ldlm.namespaces.filter-*.contention_hold_seconds
seconds. During that contended state, each new conflicting lock request
increments this counter.
.PP
The value is a diagnostic counter for observing lock contention behavior.
It is not a count of all conflicting lock requests, and it does not count
compatible requests. Writing any value to the parameter clears the counter
back to zero.
.PP
Run the command on the server that owns the namespace to be inspected. Only
namespaces that exist on the local node are shown.
.SH MODULES
This parameter applies to OST filter namespaces:
.EX
.BI ldlm.namespaces.filter- FSNAME-* .contention_events
.EE
.SH EXAMPLES
Show the contention event counters for OST filter namespaces on an OSS:
.EX
.RB "oss# " lctl " get_param " ldlm.namespaces.filter-*.contention_events
ldlm.namespaces.filter-lustre-OST0000_UUID.contention_events=0
.EE
.PP
Clear the contention event counters for OST filter namespaces on an OSS:
.EX
.RB "oss# " lctl " set_param " ldlm.namespaces.filter-*.contention_events=0
ldlm.namespaces.filter-lustre-OST0000_UUID.contention_events=0
.EE
.SH AVAILABILITY
.B ldlm.namespaces.filter-*.contention_events
is part of the
.BR lustre (7)
filesystem package since release 2.18.0.
.\" commit #
.SH SEE ALSO
.BR lustre (7),
.BR lctl-get_param (8),
.BR lctl-set_param (8)
