Date: Fri, 17 Dec 2010 18:22:50 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r216505 - head/sys/cddl/dev/cyclic/i386 Message-ID: <201012171822.oBHIMouX098401@svn.freebsd.org>
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Author: avg Date: Fri Dec 17 18:22:50 2010 New Revision: 216505 URL: http://svn.freebsd.org/changeset/base/216505 Log: cyclic xcall: use smp_no_rendevous_barrier as setup function parameter In this case we call target function only on a single CPU and do not need any synchronization at the setup stage. It's a bit non-obvious but setup function of NULL means that smp_rendezvous_cpus waits for all CPUs to arrive at the rendezvous point, but without doing any actual setup. While using smp_no_rendevous_barrier means that each CPU proceeds on its own schedule without any synchronization whatsoever. MFC after: 3 weeks Modified: head/sys/cddl/dev/cyclic/i386/cyclic_machdep.c Modified: head/sys/cddl/dev/cyclic/i386/cyclic_machdep.c ============================================================================== --- head/sys/cddl/dev/cyclic/i386/cyclic_machdep.c Fri Dec 17 16:29:06 2010 (r216504) +++ head/sys/cddl/dev/cyclic/i386/cyclic_machdep.c Fri Dec 17 18:22:50 2010 (r216505) @@ -122,6 +122,6 @@ static void reprogram(cyb_arg_t arg, hrt static void xcall(cyb_arg_t arg, cpu_t *c, cyc_func_t func, void *param) { - smp_rendezvous_cpus((cpumask_t) (1 << c->cpuid), NULL, - func, smp_no_rendevous_barrier, param); + smp_rendezvous_cpus((cpumask_t) (1 << c->cpuid), + smp_no_rendevous_barrier, func, smp_no_rendevous_barrier, param); }
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