Re: [PATCH REPOST v3 74/80] exec: cleanup qemu_minrampagesize()/qemu_maxrampagesize()

[Igor Mammedov]

On Thu, 23 Jan 2020 12:38:39 +0100
Igor Mammedov <address@hidden> wrote:

> Since all RAM is backed by hostmem backends, drop
> global -mem-path invariant and simplify code.

Looks like origin of removed here code is PPC,
could PPC folk review this please?

> Signed-off-by: Igor Mammedov <address@hidden>
> ---
> CC: address@hidden
> CC: address@hidden
> ---
>  exec.c | 51 +++++----------------------------------------------
>  1 file changed, 5 insertions(+), 46 deletions(-)
> 
> diff --git a/exec.c b/exec.c
> index 67e520d..809987c 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1667,60 +1667,19 @@ static int find_max_backend_pagesize(Object *obj, 
> void *opaque)
>   */
>  long qemu_minrampagesize(void)
>  {
> -    long hpsize = LONG_MAX;
> -    long mainrampagesize;
> -    Object *memdev_root;
> -    MachineState *ms = MACHINE(qdev_get_machine());
> -
> -    mainrampagesize = qemu_mempath_getpagesize(mem_path);
> -
> -    /* it's possible we have memory-backend objects with
> -     * hugepage-backed RAM. these may get mapped into system
> -     * address space via -numa parameters or memory hotplug
> -     * hooks. we want to take these into account, but we
> -     * also want to make sure these supported hugepage
> -     * sizes are applicable across the entire range of memory
> -     * we may boot from, so we take the min across all
> -     * backends, and assume normal pages in cases where a
> -     * backend isn't backed by hugepages.
> -     */
> -    memdev_root = object_resolve_path("/objects", NULL);
> -    if (memdev_root) {
> -        object_child_foreach(memdev_root, find_min_backend_pagesize, 
> &hpsize);
> -    }
> -    if (hpsize == LONG_MAX) {
> -        /* No additional memory regions found ==> Report main RAM page size 
> */
> -        return mainrampagesize;
> -    }
> -
> -    /* If NUMA is disabled or the NUMA nodes are not backed with a
> -     * memory-backend, then there is at least one node using "normal" RAM,
> -     * so if its page size is smaller we have got to report that size 
> instead.
> -     */
> -    if (hpsize > mainrampagesize &&
> -        (ms->numa_state == NULL ||
> -         ms->numa_state->num_nodes == 0 ||
> -         ms->numa_state->nodes[0].node_memdev == NULL)) {
> -        static bool warned;
> -        if (!warned) {
> -            error_report("Huge page support disabled (n/a for main 
> memory).");
> -            warned = true;
> -        }
> -        return mainrampagesize;
> -    }
> +    long hpsize;
> +    Object *memdev_root = object_resolve_path("/objects", NULL);
>  
> +    object_child_foreach(memdev_root, find_min_backend_pagesize, &hpsize);
>      return hpsize;
>  }
>  
>  long qemu_maxrampagesize(void)
>  {
> -    long pagesize = qemu_mempath_getpagesize(mem_path);
> +    long pagesize;
>      Object *memdev_root = object_resolve_path("/objects", NULL);
>  
> -    if (memdev_root) {
> -        object_child_foreach(memdev_root, find_max_backend_pagesize,
> -                             &pagesize);
> -    }
> +    object_child_foreach(memdev_root, find_max_backend_pagesize, &pagesize);
>      return pagesize;
>  }
>  #else