/sys/kernel/kexec_crash_cma_ranges to export all CMA regions reserved for the crashkernel to user-space. This enables user-space tools configuring kdump to determine the amount of memory reserved for the crashkernel. When CMA is used for crashkernel allocation, tools can use this information to warn users that attempting to capture user pages while CMA reservation is active may lead to unreliable or incomplete dump capture.
While adding documentation for the new sysfs interface, I realized that there was no ABI document for the existing kexec and kdump sysfs interfaces, so I added one. The first patch adds the ABI documentation for the existing kexec and kdump sysfs interfaces, and the second patch adds the /sys/kernel/kexec_crash_cma_ranges sysfs interface along with its corresponding ABI documentation. *Seeking opinions* There are already four kexec/kdump sysfs entries under /sys/kernel/, and this patch series adds one more. Should we consider moving them to a separate directory, such as /sys/kernel/kexec, to avoid polluting /sys/kernel/? For backward compatibility, we can create symlinks at the old locations for sometime and remove them in the future. Cc: Andrew Morton <[email protected]> Cc: Baoquan he <[email protected]> Cc: Jiri Bohac <[email protected]> Cc: Shivang Upadhyay <[email protected]> Cc: [email protected] Cc: [email protected] Sourabh Jain (2): Documentation/ABI: add kexec and kdump sysfs interface crash: export crashkernel CMA reservation to userspace .../ABI/testing/sysfs-kernel-kexec-kdump | 53 +++++++++++++++++++ kernel/ksysfs.c | 17 ++++++ 2 files changed, 70 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-kexec-kdump -- 2.51.0
