d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Currently there is no easy way to specify net.isr.maxthreads = all cpus. We need

Browse Source 
to specify exact number of cpus in loader.conf which get annoying when you have
mix of machines which don't have equal number of total cpus. I propose "-1" as
that value. When loader.conf has net.isr.maxthreads = -1, netisr will use all
available cpus.

In collaboration with:	davide
Reviewed by:	gnn
Differential Revision:	https://reviews.freebsd.org/D2318
MFC after:	2 weeks
Sponsored by:	Limelight Networks
This commit is contained in:
Hiren Panchasara 2015-04-25 16:12:06 +00:00
parent a12df97ed2
commit a9467c3c45
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=281984
1 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
sys/net/netisr.c
View File

@ -156,10 +156,13 @@ SYSCTL_PROC(_net_isr, OID_AUTO, dispatch, CTLTYPE_STRING | CTLFLAG_RWTUN,
/*
* Allow the administrator to limit the number of threads (CPUs) to use for
* netisr. We don't check netisr_maxthreads before creating the thread for
* CPU 0, so in practice we ignore values <= 1. This must be set at boot.
* We will create at most one thread per CPU.
* CPU 0. This must be set at boot. We will create at most one thread per CPU.
* By default we initialize this to 1 which would assign just 1 cpu (cpu0) and
* therefore only 1 workstream. If set to -1, netisr would use all cpus
* (mp_ncpus) and therefore would have those many workstreams. One workstream
* per thread (CPU).
*/
static int netisr_maxthreads = -1; /* Max number of threads. */
static int netisr_maxthreads = 1; /* Max number of threads. */
SYSCTL_INT(_net_isr, OID_AUTO, maxthreads, CTLFLAG_RDTUN,
&netisr_maxthreads, 0,
"Use at most this many CPUs for netisr processing");
@ -1120,8 +1123,10 @@ netisr_init(void *arg)
KASSERT(curcpu == 0, ("%s: not on CPU 0", __func__));
NETISR_LOCK_INIT();
if (netisr_maxthreads < 1)
netisr_maxthreads = 1;
if (netisr_maxthreads == 0 || netisr_maxthreads < -1 )
netisr_maxthreads = 1; /* default behavior */
else if (netisr_maxthreads == -1)
netisr_maxthreads = mp_ncpus; /* use max cpus */
if (netisr_maxthreads > mp_ncpus) {
printf("netisr_init: forcing maxthreads from %d to %d\n",
netisr_maxthreads, mp_ncpus);