Re: [PATCH v1 05/13] util/mmap-alloc: Factor out calculation of pagesize to mmap_pagesize()

["Murilo Opsfelder Araújo" <muriloo@linux.ibm.com>]

Hello, David.

On 2/3/20 3:31 PM, David Hildenbrand wrote:
> Factor it out and add a comment.
> 
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
> Cc: Greg Kurz <groug@kaod.org>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Acked-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>

> ---
>   util/mmap-alloc.c | 21 ++++++++++++---------
>   1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
> index 27dcccd8ec..82f02a2cec 100644
> --- a/util/mmap-alloc.c
> +++ b/util/mmap-alloc.c
> @@ -82,17 +82,27 @@ size_t qemu_mempath_getpagesize(const char *mem_path)
>       return qemu_real_host_page_size;
>   }
>   
> +static inline size_t mmap_pagesize(int fd)
> +{
> +#if defined(__powerpc64__) && defined(__linux__)
> +    /* Mappings in the same segment must share the same page size */
> +    return qemu_fd_getpagesize(fd);
> +#else
> +    return qemu_real_host_page_size;
> +#endif
> +}
> +
>   void *qemu_ram_mmap(int fd,
>                       size_t size,
>                       size_t align,
>                       bool shared,
>                       bool is_pmem)
>   {
> +    const size_t pagesize = mmap_pagesize(fd);
>       int flags;
>       int map_sync_flags = 0;
>       int guardfd;
>       size_t offset;
> -    size_t pagesize;
>       size_t total;
>       void *guardptr;
>       void *ptr;
> @@ -113,7 +123,6 @@ void *qemu_ram_mmap(int fd,
>        * anonymous memory is OK.
>        */
>       flags = MAP_PRIVATE;
> -    pagesize = qemu_fd_getpagesize(fd);
>       if (fd == -1 || pagesize == qemu_real_host_page_size) {
>           guardfd = -1;
>           flags |= MAP_ANONYMOUS;
> @@ -123,7 +132,6 @@ void *qemu_ram_mmap(int fd,
>       }
>   #else
>       guardfd = -1;
> -    pagesize = qemu_real_host_page_size;
>       flags = MAP_PRIVATE | MAP_ANONYMOUS;
>   #endif
>   
> @@ -198,15 +206,10 @@ void *qemu_ram_mmap(int fd,
>   
>   void qemu_ram_munmap(int fd, void *ptr, size_t size)
>   {
> -    size_t pagesize;
> +    const size_t pagesize = mmap_pagesize(fd);
>   
>       if (ptr) {
>           /* Unmap both the RAM block and the guard page */
> -#if defined(__powerpc64__) && defined(__linux__)
> -        pagesize = qemu_fd_getpagesize(fd);
> -#else
> -        pagesize = qemu_real_host_page_size;
> -#endif
>           munmap(ptr, size + pagesize);
>       }
>   }
> 

-- 
Murilo