Documentation/admin-guide/pstore-blk.rst

1 .. SPDX-License-Identifier: GPL-2.0
7 ------------
10 block device and non-block device before the system crashes. You can get
13     mount -t pstore pstore /sys/fs/pstore
17 ---------------------
27 Configurations for driver are all about block device and non-block device,
31 -----------------------
51 #. /dev/<disk_name><decimal> represents the device number of partition - device
53 #. /dev/<disk_name>p<decimal> - same as the above; this form is used when disk
60 #. PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF represents the unique id of
62    EFI/GPT UUID, or refer to an MSDOS partition using the format SSSSSSSS-PP,
63    where SSSSSSSS is a zero-filled hex representation of the 32-bit
64    "NT disk signature", and PP is a zero-filled hex representation of the
65    1-based partition number.
78 The chunk size in KB for oops/panic front-end. It **MUST** be a multiple of 4.
81 There are multiple chunks for oops/panic front-end depending on the remaining
82 space except other pstore front-ends.
90 The chunk size in KB for pmsg front-end. It **MUST** be a multiple of 4.
93 Unlike oops/panic front-end, there is only one chunk for pmsg front-end.
97 */sys/fs/pstore/pmsg-pstore-blk-0*.
102 The chunk size in KB for console front-end.  It **MUST** be a multiple of 4.
105 Similar to pmsg front-end, there is only one chunk for console front-end.
108 available in */sys/fs/pstore/console-pstore-blk-0*.
113 The chunk size in KB for ftrace front-end. It **MUST** be a multiple of 4.
116 Similar to oops front-end, there are multiple chunks for ftrace front-end
121 combined and available in */sys/fs/pstore/ftrace-pstore-blk-0*.
126  # mount -t pstore pstore /sys/fs/pstore
127  # mount -t debugfs debugfs /sys/kernel/debug/
129  # reboot -f
131  # mount -t pstore pstore /sys/fs/pstore
132  # tail /sys/fs/pstore/ftrace-pstore-blk-0
133  CPU:0 ts:5914676 c0063828  c0063b94  call_cpuidle <- cpu_startup_entry+0x1b8/0x1e0
134  CPU:0 ts:5914678 c039ecdc  c006385c  cpuidle_enter_state <- call_cpuidle+0x44/0x48
135  CPU:0 ts:5914680 c039e9a0  c039ecf0  cpuidle_enter_freeze <- cpuidle_enter_state+0x304/0x314
136  CPU:0 ts:5914681 c0063870  c039ea30  sched_idle_set_state <- cpuidle_enter_state+0x44/0x314
137  CPU:1 ts:5916720 c0160f59  c015ee04  kernfs_unmap_bin_file <- __kernfs_remove+0x140/0x204
138  CPU:1 ts:5916721 c05ca625  c015ee0c  __mutex_lock_slowpath <- __kernfs_remove+0x148/0x204
139  CPU:1 ts:5916723 c05c813d  c05ca630  yield_to <- __mutex_lock_slowpath+0x314/0x358
140  CPU:1 ts:5916724 c05ca2d1  c05ca638  __ww_mutex_lock <- __mutex_lock_slowpath+0x31c/0x358
155 -------------------------
160 .. kernel-doc:: fs/pstore/blk.c
164 ----------------------
183 ----------------
186 files is ``dmesg-pstore-blk-[N]`` for oops/panic front-end,
187 ``pmsg-pstore-blk-0`` for pmsg front-end and so on.  The timestamp of the
192 -----------------------------------
196 looks like a single-threaded program running on a single-core computer.
223 ----------------------
227 .. kernel-doc:: fs/pstore/zone.c
230 .. kernel-doc:: include/linux/pstore_zone.h
233 .. kernel-doc:: include/linux/pstore_blk.h