答复: [PATCH] XArray tests: allocation has to be GFP_ATOMIC under rcu_read_lock

[Li,Rongqing]

> -----邮件原件-----
> 发件人: Matthew Wilcox [mailto:wi...@infradead.org]
> 发送时间: 2019年2月3日 7:20
> 收件人: Li,Rongqing <lirongq...@baidu.com>
> 抄送: linux-kernel@vger.kernel.org
> 主题: Re: [PATCH] XArray tests: allocation has to be GFP_ATOMIC under
> rcu_read_lock
> 
> On Tue, Jan 29, 2019 at 07:08:42PM +0800, Li RongQing wrote:
> > -   XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL);
> > +   XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_ATOMIC) != NULL);
> 
> Did you try running this change in userspace too?  I don't think it'll work.
> 
> I think the right change would be:
> 

Could you send this patch?

Thanks

-Li RongQing 


> +++ b/lib/test_xarray.c
> @@ -107,8 +107,11 @@ static noinline void check_xas_retry(struct xarray
> *xa)
>         XA_BUG_ON(xa, xas.xa_node != XAS_RESTART);
>         XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) !=
> xa_mk_value(0));
>         XA_BUG_ON(xa, xas.xa_node != NULL);
> +       rcu_read_unlock();
> 
>         XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL);
> +
> +       rcu_read_lock();
>         XA_BUG_ON(xa, !xa_is_internal(xas_reload(&xas)));
>         xas.xa_node = XAS_RESTART;
>         XA_BUG_ON(xa, xas_next_entry(&xas, ULONG_MAX) !=
> xa_mk_value(0));