From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Date: Sun, 02 Jun 2002 05:50:46 +0000 Subject: Re: [linux-usb-devel] Re: hotplugging to deal with firmware download Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org Am Sonntag, 2. Juni 2002 13:11 schrieb Brad Hards: > On Mon, 3 Jun 2002 00:44, Oliver Neukum wrote: > > Am Sonntag, 2. Juni 2002 01:16 schrieben Sie: > > > On Sun, 2 Jun 2002 02:07, Oliver Neukum wrote: > > > > The problem is that this cannot simply work, because a filesystem > > > > may be mounted by nfs. > > > > > > How is this a problem? You simply need to bring the driver up before > > > you remount the nfs filesystem. If you assume that your firmware is > > > on that filesystem, then you couldn't have mounted it in the first > > > place. > > > > > > What am I missing here? > > > > Paging. As soon as user space is running, dirty pages may be written > > out And in order to run a user space firmware loader, user space must > > be functional, or am I overlooking something? > > The software support option requires swap to store to, right? That had > better be on a local disk, or it doesn't matter whether the firmware is > in userspace or not. Realistically, swap over a network block device > isn't a problem worth trying to solve. Not only swap, but any file opened for writing may be written to if you allocate memory. > > Thus as soon as you do something that allocates memory from user > > space, you may deadlock IMHO. > > If you are going to get the firmware from disk (per your alternative > suggestion), how is that going to help avoid the malloc? If I load the firmware in kernel I can allocate memory with GFP_NOFS. Regards Oliver _______________________________________________________________ Don't miss the 2002 Sprint PCS Application Developer's Conference August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel