Re: [PATCH v1] softmmu/vl: make default prealloc-threads work w/o -mem-prealloc

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/03/21 09:59, Denis Plotnikov wrote:
> Preallocation in memory backends can be specified with either global
> QEMU option "-mem-prealloc", or with per-backend property
> "prealloc=true".  In the latter case, however, the default for the
> number of preallocation threads is not set to the number of vcpus, but
> remains at 1 instead.
> 
> Fix it by setting the "prealloc-threads" sugar property of
> "memory-backend" to the number of vcpus unconditionally.
> 
> Fixes: ffac16fab3 ("hostmem: introduce "prealloc-threads" property")
> 
> Signed-off-by: Denis Plotnikov <den-plotnikov@yandex-team.ru>
> ---
>   softmmu/vl.c | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index ff488ea3e7db..e392e226a2d3 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -2300,14 +2300,17 @@ static void qemu_validate_options(void)
>   
>   static void qemu_process_sugar_options(void)
>   {
> -    if (mem_prealloc) {
> -        char *val;
> +    char *val;
>   
> -        val = g_strdup_printf("%d",
> -                 (uint32_t) qemu_opt_get_number(qemu_find_opts_singleton("smp-opts"), "cpus", 1));
> -        object_register_sugar_prop("memory-backend", "prealloc-threads", val,
> -                                   false);
> -        g_free(val);
> +    val = g_strdup_printf("%d",
> +              (uint32_t) qemu_opt_get_number(
> +                             qemu_find_opts_singleton("smp-opts"), "cpus", 1));
> +
> +    object_register_sugar_prop("memory-backend", "prealloc-threads", val,
> +                                false);
> +    g_free(val);
> +
> +    if (mem_prealloc) {
>           object_register_sugar_prop("memory-backend", "prealloc", "on", false);
>       }
>   
> 

Queued, thanks.

Paolo