On 06/02/2017 18:32, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> Unfortunately madvise DONTNEED doesn't work on hugepagetlb
> so use fallocate(FALLOC_FL_PUNCH_HOLE)
> qemu_fd_getpagesize only sets the page based off a file
> if the file is from hugetlbfs.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> exec.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/exec.c b/exec.c
> index e040cdf..c25f6b3 100644
> --- a/exec.c
> +++ b/exec.c
You should move here the "#include" from PATCH 04/16
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+#include <fcntl.h>
+#include <linux/falloc.h>
+#endif
> @@ -3324,9 +3324,20 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t
> start, size_t length)
>
> errno = ENOTSUP; /* If we are missing MADVISE etc */
>
> + if (rb->page_size == qemu_host_page_size) {
> #if defined(CONFIG_MADVISE)
> - ret = qemu_madvise(host_startaddr, length, QEMU_MADV_DONTNEED);
> + ret = qemu_madvise(host_startaddr, length, QEMU_MADV_DONTNEED);
> #endif
> + } else {
> + /* Huge page case - unfortunately it can't do DONTNEED, but
> + * it can do the equivalent by FALLOC_FL_PUNCH_HOLE in the
> + * huge page file.
> + */
> +#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
> + ret = fallocate(rb->fd, FALLOC_FL_PUNCH_HOLE |
> FALLOC_FL_KEEP_SIZE,
> + start, length);
> +#endif
> + }
> if (ret) {
> ret = -errno;
> error_report("ram_block_discard_range: Failed to discard range "
>
Reviewed-by: Laurent Vivier <lviv...@redhat.com>
