linux/tools
Guilherme G. Piccoli 0709682cdb memblock: Add reserve_mem debugfs info
When using the "reserve_mem" parameter, users aim at having an
area that (hopefully) persists across boots, so pstore infrastructure
(like ramoops module) can make use of that to save oops/ftrace logs,
for example.

There is no easy way to determine if this kernel parameter is properly
set though; the kernel doesn't show information about this memory in
memblock debugfs, neither in /proc/iomem nor dmesg. This is a relevant
information for tools like kdumpst[0], to determine if it's reliable
to use the reserved area as ramoops persistent storage; checking only
/proc/cmdline is not sufficient as it doesn't tell if the reservation
effectively succeeded or not.

Add here a new file under memblock debugfs showing properly set memory
reservations, with name and size as passed to "reserve_mem". Notice that
if no "reserve_mem=" is passed on command-line or if the reservation
attempts fail, the file is not created.

[0] https://aur.archlinux.org/packages/kdumpst

Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://patch.msgid.link/20260324012839.1991765-2-gpiccoli@igalia.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-04-01 11:19:43 +03:00
..
accounting delayacct: fix build regression on accounting tool 2026-02-12 15:45:56 -08:00
arch tools headers UAPI: Update tools' copy of linux/coresight-pmu.h 2026-03-05 17:28:44 -03:00
bootconfig bootconfig: Add bootconfig tests about braces 2026-03-13 17:49:30 +09:00
bpf resolve_btfids: Fix linker flags detection 2026-03-07 08:51:51 -08:00
build tools build: Fix rust cross compilation 2026-03-04 11:37:30 -03:00
certs
cgroup
counter
crypto
debugging kernel-chktaint: add reporting for tainted modules 2026-01-26 19:07:15 -08:00
dma
docs tools: sphinx-build-wrapper: improve its help message 2026-02-02 09:57:46 -07:00
firewire
firmware
gpio
hv
iio
include perf tools fixes for v7.0: 2026-03-13 14:24:15 -07:00
kvm/kvm_stat
laptop
leds
lib perf tools changes for v7.0: 2026-02-21 10:51:08 -08:00
memory-model
mm
net NFSD 7.0 Release Notes 2026-02-12 08:23:53 -08:00
objtool Miscellaneous objtool fixes: 2026-03-15 10:36:01 -07:00
pcmcia
perf perf synthetic-events: Fix stale build ID in module MMAP2 records 2026-03-11 17:47:42 -03:00
power cpupower: Add intel_pstate turbo boost support for Intel platforms 2026-03-03 11:18:53 -07:00
rcu
sched
sched_ext tools/sched_ext: Add -fms-extensions to bpf build flags 2026-03-02 22:00:23 -10:00
scripts tools headers: Update the syscall tables and unistd.h, to support the new 'rseq_slice_yield' syscall 2026-03-05 17:20:23 -03:00
sound
spi spi: tools: Add include folder to .gitignore 2026-02-09 12:27:31 +00:00
testing memblock: Add reserve_mem debugfs info 2026-04-01 11:19:43 +03:00
thermal
time
tracing
usb
verification
virtio
wmi
workqueue
writeback
Makefile