a Alex Bennée <alex.ben...@linaro.org> writes: > Basing the cpu_index on the number of currently allocated vCPUs fails > when vCPUs aren't removed in a LIFO manner. This is especially true > when we are allocating a cpu_index for each guest thread in > linux-user where there is no ordering constraint on their allocation > and de-allocation. > > [I've dropped the assert which is there to guard against out-of-order > removal as this should probably be caught higher up the stack. Maybe > we could just ifdef CONFIG_SOFTTMU it?] > > Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > Cc: Nikolay Igotti <igo...@gmail.com> > Cc: Paolo Bonzini <pbonz...@redhat.com> > Cc: Igor Mammedov <imamm...@redhat.com> > Cc: Eduardo Habkost <ehabk...@redhat.com> > --- > cpus-common.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/cpus-common.c b/cpus-common.c > index 55d5df89237..5a7d2f6132b 100644 > --- a/cpus-common.c > +++ b/cpus-common.c > @@ -61,13 +61,14 @@ static bool cpu_index_auto_assigned; > static int cpu_get_free_index(void) > { > CPUState *some_cpu; > - int cpu_index = 0; > + int max_cpu_index = 0; > > cpu_index_auto_assigned = true; > CPU_FOREACH(some_cpu) { > - cpu_index++; > + max_cpu_index = MAX(some_cpu->cpu_index, max_cpu_index); > } > - return cpu_index; > + max_cpu_index++; > + return max_cpu_index; > }
OK some ending up with cpu_index = 1 threw off devices that would do qemu_get_cpu(0) so I've tweaked the algorithm to: static int cpu_get_free_index(void) { CPUState *some_cpu; int max_cpu_index = 0; cpu_index_auto_assigned = true; CPU_FOREACH(some_cpu) { if (some_cpu->cpu_index >= max_cpu_index) { max_cpu_index = some_cpu->cpu_index + 1; } } return max_cpu_index; } > > void cpu_list_add(CPUState *cpu) > @@ -90,8 +91,6 @@ void cpu_list_remove(CPUState *cpu) > return; > } > > - assert(!(cpu_index_auto_assigned && cpu != QTAILQ_LAST(&cpus))); > - > QTAILQ_REMOVE_RCU(&cpus, cpu, node); > cpu->cpu_index = UNASSIGNED_CPU_INDEX; > } -- Alex Bennée