(2013/11/15 23:26), Vivek Goyal wrote: > On Fri, Nov 15, 2013 at 06:41:52PM +0900, HATAYAMA Daisuke wrote: > > [..] >>> Given the fact that hpa does not like fixing it in kernel. We are left >>> with option of fixing it in following places. >>> >>> - Drop partial pages in kexec-tools >>> - Drop partial pages in makeudmpfile. >>> - Read partial pages using read() interface in makedumpfile >>> - Modify /proc/vmcore to copy partial pages in second kernel's memory. >>> >>> It is not clear to me that partial pages are really useful. So I want >>> to avoid modifying /proc/vmcore to deal with partial pages and increase >>> complexity. >>> >>> So fixing makedumpfile (either option2 or option 3) seems least risky >>> to me. In fact I would say let us keep it simple and truncate partial >>> pages in makedumpfile to keep it simple. And look at option 3 once we >>> have a strong use case for partial pages. >>> >>> What do you think? >>> >> >> As you say, it's not clear that partial pages are really useful, but on >> the other hand, it seems to me not clear that they are really useless. >> I think we should get them as long as we have access to them. >> >> It seems best to me the option 3). Switching between read and mmap would >> be not so complex and also it's by far flexible in makedumpfile than in >> kernel. > > Ok, I am fine with option 3. It is more complicated option but safe > option. It sounds reasonable also to me. > Is there any chance that you could look into fixing this. I have no > experience writing code for makedumpfile. I'll send a patch to fix this soon. Thanks Atsushi Kumagai
