From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: do_domctl and EAGAIN Date: Tue, 07 Apr 2009 10:19:20 +0200 Message-ID: <49DB0C88.50403@ts.fujitsu.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > On 07/04/2009 08:41, "Juergen Gross" wrote: > >> Keir Fraser wrote: >>> Only DOMCTL_destroydomain returns EAGAIN. No domctl returns EINTR. >> do_domctl uses ioctl. >> ioctl can return EINTR if a signal is caught. > > Our privcmd hypercall ioctl() is non-blocking and hence I don't think can > return EINTR. In fact ioctl() is used in loads of places throughout our > toolstack and in qemu, and I don't think EINTR is checked by any caller, nor > is EINTR mentioned in the ioctl man page. On my system the ioctl man page does mention it: ERRORS Under the following general conditions, ioctl() shall fail if: EBADF The fildes argument is not a valid open file descriptor. EINTR A signal was caught during the ioctl() operation. In the non-blocking case this might be irrelevant. Are you sure this is no issue in any case? Juergen -- Juergen Gross Principal Developer Operating Systems TSP ES&S SWE OS6 Telephone: +49 (0) 89 636 47950 Fujitsu Technolgy Solutions e-mail: juergen.gross@ts.fujitsu.com Otto-Hahn-Ring 6 Internet: ts.fujitsu.com D-81739 Muenchen Company details: ts.fujitsu.com/imprint.html