Copyright (c) 2025 The NetBSD Foundation
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
.Dd December 31, 2025 .Dt CURLWP_BIND 9 .Os .Sh NAME .Nm curlwp_bind , .Nm curlwp_bindx .Nd temporarily bind the current thread to the running CPU .Sh SYNOPSIS n sys/lwp.h .Ft int .Fn curlwp_bind "void" .Ft void .Fn curlwp_bindx "int bound" .Sh DESCRIPTION .Fn curlwp_bind temporarily binds the current thread to the running CPU and returns a cookie .Fa bound which must be passed to .Fn curlwp_bindx when done.
p During this time, the thread may sleep and may be preempted, but it will never migrate to another CPU until .Fn curlwp_bindx . If the CPU is offlined, the thread will not run again until the CPU is onlined again.
p Calls to .Fn curlwp_bind and .Fn curlwp_bindx may be nested as long as the matching cookie is passed. .Sh EXAMPLES For temporary access to resources protected by .Xr psref 9 from an arbitrary thread: d -literal -offset indent struct psref psref; int bound, s; bound = curlwp_bind(); s = pserialize_read_enter(); IFADDR_READER_FOREACH(ifa, ifp) { ifa_acquire(ifa, &psref); pserialize_read_exit(s); /* * ifa is now stable, even if caller is preempted * or sleeps */ s = pserialize_read_enter(); ifa_release(ifa, &psref); } pserialize_read_exit(s); curlwp_bindx(bound); .Ed .Sh CODE REFERENCES
a sys/sys/lwp.h .Sh SEE ALSO .Xr localcount 9 , .Xr pserialize 9 , .Xr psref 9 , .Xr spl 9 .Sh HISTORY The .Nm function first appeared in .Nx 8.0 to support .Xr psref 9 .
Indexes created Sun Feb 22 16:20:20 UTC 2026