On 02/10/2014 05:32 PM, Alexey Kardashevskiy wrote:
> At the moment if the user asked for huge pages and there is no more huge
> pages, QEMU prints warning and falls back to the anonymous memory
> allocator which is quite easy not to notice. QEMU also does so even
> if the user specified -mem-prealloc and it seems wrong as the user
> specifically requested huge pages for the entire RAM but QEMU failed to do
> so and continued. On PPC64 this will produce a fragile guest as QEMU
> tells the guest via device-tree that it can use huge pages when it
> actually cannot.
>
> This adds message+exit if RAM cannot be preallocated from huge pages.
Too bad? Should I increase my personal pinging timeout from 1 to 2 weeks to
avoid annoying the community? :) Thanks!
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> ---
> exec.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/exec.c b/exec.c
> index 9ad0a4b..deb8279 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1041,6 +1041,10 @@ static void *file_ram_alloc(RAMBlock *block,
>
> area = mmap(0, memory, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
> if (area == MAP_FAILED) {
> + if (mem_prealloc) {
> + perror("file_ram_alloc: failed to preallocate RAM");
> + exit(1);
> + }
> perror("file_ram_alloc: can't mmap RAM pages");
> close(fd);
> return (NULL);
>
--
Alexey
