From 505ad3a8b7fd3b91ab39c829ca6636cd264198c7 Mon Sep 17 00:00:00 2001 From: George Dunlap Date: Fri, 5 Aug 2016 14:07:57 +0200 Subject: [PATCH] xen: Remove buggy initial placement algorithm The initial placement algorithm sometimes picks cpus outside of the mask it's given, does a lot of unnecessary bitmasking, does its own separate load calculation, and completely ignores vcpu hard and soft affinities. Just get rid of it and rely on the schedulers to do initial placement. Signed-off-by: George Dunlap Reviewed-by: Dario Faggioli Acked-by: Andrew Cooper master commit: d5438accceecc8172db2d37d98b695eb8bc43afc master date: 2016-07-26 10:44:06 +0100 --- xen/common/domctl.c | 50 +-------------------------------------------- 1 file changed, 1 insertion(+), 49 deletions(-) diff --git a/xen/common/domctl.c b/xen/common/domctl.c index 36412967b7..d76cd278f9 100644 --- a/xen/common/domctl.c +++ b/xen/common/domctl.c @@ -215,54 +215,6 @@ void getdomaininfo(struct domain *d, struct xen_domctl_getdomaininfo *info) memcpy(info->handle, d->handle, sizeof(xen_domain_handle_t)); } -static unsigned int default_vcpu0_location(cpumask_t *online) -{ - struct domain *d; - struct vcpu *v; - unsigned int i, cpu, nr_cpus, *cnt; - cpumask_t cpu_exclude_map; - - /* Do an initial CPU placement. Pick the least-populated CPU. */ - nr_cpus = cpumask_last(&cpu_online_map) + 1; - cnt = xzalloc_array(unsigned int, nr_cpus); - if ( cnt ) - { - rcu_read_lock(&domlist_read_lock); - for_each_domain ( d ) - for_each_vcpu ( d, v ) - if ( !test_bit(_VPF_down, &v->pause_flags) - && ((cpu = v->processor) < nr_cpus) ) - cnt[cpu]++; - rcu_read_unlock(&domlist_read_lock); - } - - /* - * If we're on a HT system, we only auto-allocate to a non-primary HT. We - * favour high numbered CPUs in the event of a tie. - */ - cpumask_copy(&cpu_exclude_map, per_cpu(cpu_sibling_mask, 0)); - cpu = cpumask_first(&cpu_exclude_map); - i = cpumask_next(cpu, &cpu_exclude_map); - if ( i < nr_cpu_ids ) - cpu = i; - for_each_cpu(i, online) - { - if ( cpumask_test_cpu(i, &cpu_exclude_map) ) - continue; - if ( (i == cpumask_first(per_cpu(cpu_sibling_mask, i))) && - (cpumask_next(i, per_cpu(cpu_sibling_mask, i)) < nr_cpu_ids) ) - continue; - cpumask_or(&cpu_exclude_map, &cpu_exclude_map, - per_cpu(cpu_sibling_mask, i)); - if ( !cnt || cnt[i] <= cnt[cpu] ) - cpu = i; - } - - xfree(cnt); - - return cpu; -} - bool_t domctl_lock_acquire(void) { /* @@ -678,7 +630,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl) continue; cpu = (i == 0) ? - default_vcpu0_location(online) : + cpumask_any(online) : cpumask_cycle(d->vcpu[i-1]->processor, online); if ( alloc_vcpu(d, i, cpu) == NULL ) -- 2.39.5