Author: hiren Date: Sat Apr 25 16:12:06 2015 New Revision: 281984 URL: https://svnweb.freebsd.org/changeset/base/281984
Log: Currently there is no easy way to specify net.isr.maxthreads = all cpus. We need 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 Modified: head/sys/net/netisr.c Modified: head/sys/net/netisr.c ============================================================================== --- head/sys/net/netisr.c Sat Apr 25 15:43:12 2015 (r281983) +++ head/sys/net/netisr.c Sat Apr 25 16:12:06 2015 (r281984) @@ -156,10 +156,13 @@ SYSCTL_PROC(_net_isr, OID_AUTO, dispatch /* * 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); _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
