Hello Jan,
On 08/24/2018 02:27 PM, Jan Stancek wrote:
> Since the rework done in a49bd4d71637 ("mm, numa: rework do_pages_move"),
> move_pages() can return also positive value.
>
> Signed-off-by: Jan Stancek <jstancek@xxxxxxxxxx>
> ---
> man2/move_pages.2 | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> https://github.com/linux-test-project/ltp/issues/388
>
> diff --git a/man2/move_pages.2 b/man2/move_pages.2
> index f2c4f7f7a269..35cf6de1ba78 100644
> --- a/man2/move_pages.2
> +++ b/man2/move_pages.2
> @@ -157,9 +157,11 @@ The page is not present.
> .B -ENOMEM
> Unable to allocate memory on target node.
> .SH RETURN VALUE
> -On success
> +On success (since 4.17)
> .BR move_pages ()
> -returns zero.
> +returns the number of pages that could not be moved
> +(i.e., a return of zero means that all pages were successfully moved,
> +older kernels return 0).
> .\" FIXME . Is the following quite true: does the wrapper in numactl
> .\" do the right thing?
> On error, it returns \-1, and sets
The wording here seems a bit confusing, because the detail about
older kernel behavior is hidden in a parenthetical aside. Can you
confirm what I understand:
[[
Before Linux 4.17, move_pages() always returned 0 on success.
[But, what is the return value if not all of the pages could
be moved? Is it 0 or -1?]
Since Linux, a successful call to move_pages() returns the number
of pages that could not be moved (i.e., a return of zero means that
all pages were successfully moved, older kernels return 0).
]]
If that's correct, then I think the new text should read more
like that, withe open question answered.
How does that sound?
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
