On Sat, Dec 10, 2011 at 12:39 PM, Pandu Poluan <pa...@poluan.info> wrote: > On Dec 11, 2011 12:02 AM, "Grant Edwards" <grant.b.edwa...@gmail.com> wrote: >> On 2011-12-10, Pandu Poluan <pa...@poluan.info> wrote: >> >> > And even you can't guarantee that the kernels are the same. Many distros >> > introduce their own distro-specific patches to the vanilla kernel. >> >> RedHat is particularly bad about this. I maintain a couple Linux >> drivers that have to work with a wide range of kernel versions. There >> are lot's of #ifdef's that depend on not only the kernel and some of >> them also have to check whether it's a _RedHat_ kernel or not, since >> RedHat is fond of shipping a kernel with version X.Y.Z that isn't even >> close to compatible with the driver API for vanilla kernel X.Y.Z. >> >> > With Gentoo, it's even more complicated, as most experienced >> > Gentooroids will configure and compile their own kernels. >> >> I've never had to add special code to a driver to handle the Gentoo >> version of a kernel. >> > > Ah, I see that I might have misconstrued myself. My bad. > > Regarding drivers: usually they're no big deal, since the 'infrastructure' > portions of the kernel (e.g., SCSI disk support) are most likely have been > enabled. > > For most applications, usually they don't really care what's in the kernel > since they operate at a quite high-level. > > Problems might arise though if you're doing exotic things. For example: If I > built the IPset portion as 'built-in' into the kernel, I won't be able to > install xtables-addons. This is due to the package wanting to install its > own set of IPset modules. > > Fortunately, such cases are few and far between in the Gentooverse. People > doing exotic things are naturally expected to Know What They Are Doing™ :-)
Speaking from experience, the real difficulty is knowing that you're doing something exotic. Once you find out, you generally have two options: Follow the route most people go (such as is happening with udev), or help fix the system so that your desired approach still works (such as the fellow who's been working with mdev). If you're constantly exploring, you'll very likely hit the exotic edge cases, but then that's going to be part of learning the thing you're exploring. Gentoo can be really great for that. Even better, in that it's often not that hard (after a while) to help smooth those edges, making it easier to go on exploring. -- :wq
