Re: [Qemu-devel] [PATCH v6 07/33] util: introduce qemu_file_get_page_size()

[Vladimir Sementsov-Ogievskiy]

logic is changed:
    in old version gethugepagesize on statfs error generates exit(1)
    in new it returns getpagesize() in this case (through fd_getpagesize)
(I think, fd_getpagesize should be fixed to handle error)

also, in new version for windows we have getpagesize(), when in old 
version there was no difference (how did it work?). May be it's ok, but 
should be mentioned in commit message


On 30.10.2015 08:56, Xiao Guangrong wrote:
> There are three places use the some logic to get the page size on
> the file path or file fd
>
> This patch introduces qemu_file_get_page_size() to unify the code
>
> Signed-off-by: Xiao Guangrong <address@hidden>
> ---
>   include/qemu/osdep.h |  1 +
>   target-ppc/kvm.c     | 21 +++------------------
>   util/oslib-posix.c   | 16 ++++++++++++++++
>   util/oslib-win32.c   |  5 +++++
>   4 files changed, 25 insertions(+), 18 deletions(-)
>
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index b568424..d4dde02 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -302,4 +302,5 @@ int qemu_read_password(char *buf, int buf_size);
>    */
>   pid_t qemu_fork(Error **errp);
>   
> +size_t qemu_file_get_page_size(const char *mem_path);
>   #endif
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index ac70f08..c661f1c 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -308,28 +308,13 @@ static void kvm_get_smmu_info(PowerPCCPU *cpu, struct 
> kvm_ppc_smmu_info *info)
>   
>   static long gethugepagesize(const char *mem_path)
>   {
> -    struct statfs fs;
> -    int ret;
> -
> -    do {
> -        ret = statfs(mem_path, &fs);
> -    } while (ret != 0 && errno == EINTR);
> +    long size = qemu_file_get_page_size(mem_path);
>   
> -    if (ret != 0) {
> -        fprintf(stderr, "Couldn't statfs() memory path: %s\n",
> -                strerror(errno));
> +    if (!size) {
>           exit(1);
>       }
>   
> -#define HUGETLBFS_MAGIC       0x958458f6
> -
> -    if (fs.f_type != HUGETLBFS_MAGIC) {
> -        /* Explicit mempath, but it's ordinary pages */
> -        return getpagesize();
> -    }
> -
> -    /* It's hugepage, return the huge page size */
> -    return fs.f_bsize;
> +    return size;
>   }
>   
>   static int find_max_supported_pagesize(Object *obj, void *opaque)
> diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> index 914cef5..ad94c5a 100644
> --- a/util/oslib-posix.c
> +++ b/util/oslib-posix.c
> @@ -360,6 +360,22 @@ static size_t fd_getpagesize(int fd)
>       return getpagesize();
>   }
>   
> +size_t qemu_file_get_page_size(const char *path)
> +{
> +    size_t size = 0;
> +    int fd = qemu_open(path, O_RDONLY);
> +
> +    if (fd < 0) {
> +        fprintf(stderr, "Could not open %s.\n", path);
> +        goto exit;
> +    }
> +
> +    size = fd_getpagesize(fd);
> +    qemu_close(fd);
> +exit:
> +    return size;
> +}
> +
>   void os_mem_prealloc(int fd, char *area, size_t memory)
>   {
>       int ret;
> diff --git a/util/oslib-win32.c b/util/oslib-win32.c
> index 09f9e98..a18aa87 100644
> --- a/util/oslib-win32.c
> +++ b/util/oslib-win32.c
> @@ -462,6 +462,11 @@ size_t getpagesize(void)
>       return system_info.dwPageSize;
>   }
>   
> +size_t qemu_file_get_page_size(const char *path)
> +{
> +    return getpagesize();
> +}
> +
>   void os_mem_prealloc(int fd, char *area, size_t memory)
>   {
>       int i;


--
Best regards,
Vladimir
* now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.