Messages in this thread | | | Date | Thu, 17 Jun 2010 13:46:22 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH 12/12] Unplug emulated disks and nics |
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On Thu, Jun 17, 2010 at 04:42:14PM +0100, Stefano Stabellini wrote: > On Mon, 14 Jun 2010, Konrad Rzeszutek Wilk wrote: > > > +#if (defined(CONFIG_XEN_NETDEV_FRONTEND) || \ > > > + defined(CONFIG_XEN_NETDEV_FRONTEND_MODULE)) && \ > > > + (defined(CONFIG_XEN_PLATFORM_PCI) || \ > > > + defined(CONFIG_XEN_PLATFORM_PCI_MODULE)) > > > + printk(KERN_INFO "Netfront and the Xen platform PCI driver have " > > > + "been compiled for this kernel: unplug emulated NICs.\n"); > > > + xen_emul_unplug |= XEN_UNPLUG_ALL_NICS; > > > +#endif > > > +#if (defined(CONFIG_XEN_BLKDEV_FRONTEND) || \ > > > + defined(CONFIG_XEN_BLKDEV_FRONTEND_MODULE)) && \ > > > + (defined(CONFIG_XEN_PLATFORM_PCI) || \ > > > + defined(CONFIG_XEN_PLATFORM_PCI_MODULE)) > > > + printk(KERN_INFO "Blkfront and the Xen platform PCI driver have " > > > + "been compiled for this kernel: unplug emulated disks.\n" > > > + "You might have to change the root device\n" > > > + "from /dev/hd[a-d] to /dev/xvd[a-d]\n" > > > + "in your root= kernel command line option\n"); > > > + xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS; > > > +#endif > > > > Wow. Can you move those checks to the header file and make it deal with > > the #ifdef and setting of xen_emul_unplug? > > > > I tried, but it didn't improve the elegance of the code, mainly because I > want to keep the printk in place, so the code would look very much like > this, but instead of being in platform-pci-unplug.c would be in > platform_pci.h.
If was thinking of something like this in the header file:
int xen_must_unplug_nics() { #if (defined(CONFIG_XEN_NETDEV_FRONTEND) || \ defined(CONFIG_XEN_NETDEV_FRONTEND_MODULE)) && \ (defined(CONFIG_XEN_PLATFORM_PCI) || \ defined(CONFIG_XEN_PLATFORM_PCI_MODULE)) return 1; #else return 0; }
and then your code would be:
if (xen_must_unplug_nics()) { printk(".. blah blah "); xen_emul_unplug |- XEN_unPLIG_ALL_NICS; }
and similar for the IDE disks.
> > > > > + } > > > + /* Now unplug the emulated devices */ > > > + if (xen_platform_pci_enabled && !(xen_emul_unplug & XEN_UNPLUG_IGNORE)) > > > + outw(xen_emul_unplug, XEN_IOPORT_UNPLUG); > > > +} > > > + > > > +static int __init parse_xen_emul_unplug(char *arg) > > > +{ > > > + char *p, *q; > > > + > > > + for (p = arg; p; p = q) { > > > + q = strchr(arg, ','); > > > + if (q) > > > + *q++ = '\0'; > > > + if (!strcmp(p, "all")) > > > + xen_emul_unplug |= XEN_UNPLUG_ALL; > > > > strncmp.. > > > > is it really needed considering that we know that both strings are NULL > terminated and one of them is a constant?
Please do.
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