On Mon, Feb 25, 2019 at 5:45 PM Borislav Petkov <b...@alien8.de> wrote: > > On Mon, Feb 25, 2019 at 03:59:56PM +0800, Pingfan Liu wrote: > > crashkernel=x@y option may fail to reserve the required memory region if > > KASLR puts kernel into the region. To avoid this uncertainty, making KASLR > > skip the required region. > > Lemme see if I understand this correctly: supplying crashkernel=X@Y > influences where KASLR would put the randomized kernel. And it should be
Yes, you get it. > the other way around, IMHO. crashkernel= will have to "work" with KASLR > to find a suitable range and if the reservation at Y fails, then we tell > the user to try the more relaxed variant crashkernel=M. > I follow Baoquan's opinion. Due to the randomness caused by KASLR, a user may be surprised to find crashkernel=x@y not working sometime. If kernel can help them out of this corner automatically, then no need to bother them with the message to use alternative method crashkernel=M. Anyway it is a cheap method already used by other options like hugepages and memmap in handle_mem_options(). If commitment, then do it without failure. Or just removing crashkernel=x@y option on x86. Thanks and regards, Pingfan > -- > Regards/Gruss, > Boris. > > Good mailing practices for 400: avoid top-posting and trim the reply.
