diff options
| -rw-r--r-- | util/mmap-alloc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c index 54793a5dcf..5cd7f71ac3 100644 --- a/util/mmap-alloc.c +++ b/util/mmap-alloc.c @@ -50,10 +50,11 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared) #if defined(__powerpc64__) && defined(__linux__) /* On ppc64 mappings in the same segment (aka slice) must share the same * page size. Since we will be re-allocating part of this segment - * from the supplied fd, we should make sure to use the same page size, - * unless we are using the system page size, in which case anonymous memory - * is OK. Use align as a hint for the page size. - * In this case, set MAP_NORESERVE to avoid allocating backing store memory. + * from the supplied fd, we should make sure to use the same page size, to + * this end we mmap the supplied fd. In this case, set MAP_NORESERVE to + * avoid allocating backing store memory. + * We do this unless we are using the system page size, in which case + * anonymous memory is OK. */ int anonfd = fd == -1 || qemu_fd_getpagesize(fd) == getpagesize() ? -1 : fd; int flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE; |