On 07/17, Austin S Hemmelgarn wrote: > > On 2015-07-17 14:19, Oleg Nesterov wrote: >> On 07/17, Austin S Hemmelgarn wrote: >>> >>> On 2015-07-17 13:55, Oleg Nesterov wrote: >>>> On 07/17, Benjamin LaHaise wrote: >>>>> >>>>> Don't add BUG(). It's the equivalent approach of saying "I think this code >>>>> isn't needed, but I'm lazy and not going to remove it properly." >>>> >>>> There is another interpretation: I think this code must be never called, >>>> if it is actually called we have a serious problem which should be loudly >>>> reported. >>>> >>> And not compiling it at all _will_ loudly report it, it'll just report >>> it during linking instead of at run-time, which is a much better time to >>> shout about it. >> >> And how can we do this? >> > If a function that isn't defined (for example, you use a #if block to > comment it out under certain circumstances), then the link will fail > rather noisily something references it. This is what we are trying to fix. > We already know during the > compile that it's a NOMMU kernel, so anything that calls it on a MMU > enabled kernel can have a compile time check added It already has. memory.c is not compiled if NOMMU. The problem is aio_ring_vm_ops which references this function. And btw filemap_fault() too. And just in case, I won't mind to add ifdef(CONFIG_MMU) there, I am waiting for reply from Benjamin. > instead of doing the > check at runtime (or even just calling it without checking), thus even > further reducing code size. So what exactly do you suggest to fix the problem? I agree with any solution which satisfies the maintainers. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
