On 08/19/2016 11:57 PM, Jonathan Corbet wrote: > On Fri, 19 Aug 2016 08:33:21 +0800 > "Zhou, Wenjian/???" <zhouwj-fnst at cn.fujitsu.com> wrote: > >> I was also confused by maxcpus and nr_cpus before writing this patch. >> I think it is a good choice to describe it in kernel-parameters.txt. >> >> Then, only two things need to be done I think. >> One is move the above description to maxcpus= in kernel-parameters.txt. >> And the other is replace maxcpus with maxcpus/nr_cpus in kdump.txt. >> >> How do you think? > > That is not quite what I had in mind, sorry. What I would really like to > see in kernel-parameters.txt is an explanation of how those two parameters > differ - what do they do differently and how should a user choose one over > the other? What we have now offers no guidance in that matter. > I thought about it. I think user may not need this. What user really want to know is how to choose. And it is also not a hard work. If nr_cpus is not supported by the ARCH, use maxcpus. Otherwise, nr_cpus. The reason why maxcpus still exists is nr_cpus can't be supported by some ARCHes. I think it may be why the author didn't write too much description of it. > I suspect that may be a bit more than you had signed up to do. As an > intermediate step, how about this: rather than tacking on those lines in > kdump.txt, rewrite that paragraph to simply say what the reader should > use. If nr_cpus is good for everybody, just say that, but your previous > patch suggests that the situation isn't quite that simple? > Actually, if nr_cpus always usable, there won't be these discussions. -- Thanks Zhou
