On Thu, 5 Apr 2018 12:20:01 +1000
David Gibson <da...@gibson.dropbear.id.au> wrote:
> qemu_mempath_getpagesize() gets the effective (host side) page size for
> a block of memory backed by an mmap()ed file on the host. It requires
> the mem_path parameter to be non-NULL.
>
> This ends up meaning all the callers need a different case for handling
> anonymous memory (for memory-backend-ram or default memory with -mem-path
> is not specified).
>
> We can make all those callers a little simpler by
by "having" ?
> qemu_mempath_getpagesize() accept NULL, and treat that as the anonymous
> memory case.
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
Reviewed-by: Greg Kurz <gr...@kaod.org>
> exec.c | 21 ++++++---------------
> target/ppc/kvm.c | 8 ++------
> util/mmap-alloc.c | 26 ++++++++++++++------------
> 3 files changed, 22 insertions(+), 33 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 02b1efebb7..b38b004563 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1488,19 +1488,14 @@ void ram_block_dump(Monitor *mon)
> */
> static int find_max_supported_pagesize(Object *obj, void *opaque)
> {
> - char *mem_path;
> long *hpsize_min = opaque;
>
> if (object_dynamic_cast(obj, TYPE_MEMORY_BACKEND)) {
> - mem_path = object_property_get_str(obj, "mem-path", NULL);
> - if (mem_path) {
> - long hpsize = qemu_mempath_getpagesize(mem_path);
> - g_free(mem_path);
> - if (hpsize < *hpsize_min) {
> - *hpsize_min = hpsize;
> - }
> - } else {
> - *hpsize_min = getpagesize();
> + char *mem_path = object_property_get_str(obj, "mem-path", NULL);
> + long hpsize = qemu_mempath_getpagesize(mem_path);
> + g_free(mem_path);
> + if (hpsize < *hpsize_min) {
> + *hpsize_min = hpsize;
> }
> }
>
> @@ -1513,11 +1508,7 @@ long qemu_getrampagesize(void)
> long mainrampagesize;
> Object *memdev_root;
>
> - if (mem_path) {
> - mainrampagesize = qemu_mempath_getpagesize(mem_path);
> - } else {
> - mainrampagesize = getpagesize();
> - }
> + mainrampagesize = qemu_mempath_getpagesize(mem_path);
>
> /* it's possible we have memory-backend objects with
> * hugepage-backed RAM. these may get mapped into system
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 1bd38c6a90..f393eae127 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -496,12 +496,8 @@ bool kvmppc_is_mem_backend_page_size_ok(const char
> *obj_path)
> char *mempath = object_property_get_str(mem_obj, "mem-path", NULL);
> long pagesize;
>
> - if (mempath) {
> - pagesize = qemu_mempath_getpagesize(mempath);
> - g_free(mempath);
> - } else {
> - pagesize = getpagesize();
> - }
> + pagesize = qemu_mempath_getpagesize(mempath);
> + g_free(mempath);
>
> return pagesize >= max_cpu_page_size;
> }
> diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
> index 2fd8cbcc6f..fd329eccd8 100644
> --- a/util/mmap-alloc.c
> +++ b/util/mmap-alloc.c
> @@ -50,19 +50,21 @@ size_t qemu_mempath_getpagesize(const char *mem_path)
> struct statfs fs;
> int ret;
>
> - do {
> - ret = statfs(mem_path, &fs);
> - } while (ret != 0 && errno == EINTR);
> -
> - if (ret != 0) {
> - fprintf(stderr, "Couldn't statfs() memory path: %s\n",
> - strerror(errno));
> - exit(1);
> - }
> + if (mem_path) {
> + do {
> + ret = statfs(mem_path, &fs);
> + } while (ret != 0 && errno == EINTR);
>
> - if (fs.f_type == HUGETLBFS_MAGIC) {
> - /* It's hugepage, return the huge page size */
> - return fs.f_bsize;
> + if (ret != 0) {
> + fprintf(stderr, "Couldn't statfs() memory path: %s\n",
> + strerror(errno));
> + exit(1);
> + }
> +
> + if (fs.f_type == HUGETLBFS_MAGIC) {
> + /* It's hugepage, return the huge page size */
> + return fs.f_bsize;
> + }
> }
> #ifdef __sparc__
> /* SPARC Linux needs greater alignment than the pagesize */
