Introduce a function to get reserved memory size
Resolves: bz2232499
Upstream: Fedora Rawhide
Conflict: None
commit 4b7b7736eef8c682a8af07081d7f06eeb774172f
Author: Sourabh Jain <sourabhjain@linux.ibm.com>
Date: Wed Aug 2 20:36:48 2023 +0530
Introduce a function to get reserved memory size
The size of the reserved memory in the functions show_reserved_mem,
check_crash_mem_reserved, and do_estimate are fetched from the sysfs
node `/sys/kernel/kexec_crash_size`. However, in the case of fadump,
the reserved area size is instead present in
/sys/kernel/fadump/mem_reserved.
For example:
$ kdumpctl showmem
kdump: Dump mode is fadump
kdump: Reserved 0MB memory for crash kernel
The above command showed 0MB for Reserved memory which is incorrect, the
actual reservation was 2048MB.
To resolve this issue a new helper function is introduced to fetch
reserved memory size based on the dump mode. For "fadump" mode,
it looks in `/sys/kernel/fadump/mem_reserved`, otherwise, it uses
`/sys/kernel/kexec_crash_size`. And all functions that previously
fetching reserved memory directly from `/sys/kernel/kexec_crash_size`
sysfs node are now updated to use this new function to get the reserved
memory size.
With the fix in place, the `kdumpctl showmem` command will now display
correct reserved memory size.
$ kdumpctl showmem
kdump: Dump mode is fadump
kdump: Reserved 2048MB memory for crash kernel
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reported-by: Sachin P Bappalige <sachinpb@linux.vnet.ibm.com>
Reviewed-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Lichen Liu <lichliu@redhat.com>