On Wed, Aug 17, 2016 at 1:20 AM, Dave Young <dyoung at redhat.com> wrote: > On 08/17/16 at 09:50am, Xunlei Pang wrote: >> "/sys/kernel/kexec_crash_size" only handles crashk_res, it >> is fine in most cases, but sometimes we have crashk_low_res. >> For example, when "crashkernel=size[KMG],high" combined with >> "crashkernel=size[KMG],low" is used for 64-bit x86. >> >> Like crashk_res, we introduce the corresponding sysfs file >> "/sys/kernel/kexec_crash_low_size" for crashk_low_res. >> >> So, the exact total reserved memory is the sum of the two. >> >> crashk_low_res can also be shrunk via this new interface, >> and users should be aware of what they are doing. ... >> @@ -218,6 +238,7 @@ static struct attribute * kernel_attrs[] = { >> #ifdef CONFIG_KEXEC_CORE >> &kexec_loaded_attr.attr, >> &kexec_crash_loaded_attr.attr, >> + &kexec_crash_low_size_attr.attr, >> &kexec_crash_size_attr.attr, >> &vmcoreinfo_attr.attr, >> #endif would be better if you can use attribute_group .is_visible to control showing of crash_low_size only when the crash_base is above 4G. Thanks Yinghai