1 # SPDX-License-Identifier: GPL-2.0-only 1 # SPDX-License-Identifier: GPL-2.0-only
2 config PROC_FS 2 config PROC_FS
3 bool "/proc file system support" if EX 3 bool "/proc file system support" if EXPERT
4 default y 4 default y
5 help 5 help
6 This is a virtual file system provid 6 This is a virtual file system providing information about the status
7 of the system. "Virtual" means that 7 of the system. "Virtual" means that it doesn't take up any space on
8 your hard disk: the files are create 8 your hard disk: the files are created on the fly by the kernel when
9 you try to access them. Also, you ca 9 you try to access them. Also, you cannot read the files with older
10 version of the program less: you nee 10 version of the program less: you need to use more or cat.
11 11
12 It's totally cool; for example, "cat 12 It's totally cool; for example, "cat /proc/interrupts" gives
13 information about what the different 13 information about what the different IRQs are used for at the moment
14 (there is a small number of Interrup 14 (there is a small number of Interrupt ReQuest lines in your computer
15 that are used by the attached device 15 that are used by the attached devices to gain the CPU's attention --
16 often a source of trouble if two dev 16 often a source of trouble if two devices are mistakenly configured
17 to use the same IRQ). The program pr 17 to use the same IRQ). The program procinfo to display some
18 information about your system gather 18 information about your system gathered from the /proc file system.
19 19
20 Before you can use the /proc file sy 20 Before you can use the /proc file system, it has to be mounted,
21 meaning it has to be given a locatio 21 meaning it has to be given a location in the directory hierarchy.
22 That location should be /proc. A com 22 That location should be /proc. A command such as "mount -t proc proc
23 /proc" or the equivalent line in /et 23 /proc" or the equivalent line in /etc/fstab does the job.
24 24
25 The /proc file system is explained i 25 The /proc file system is explained in the file
26 <file:Documentation/filesystems/proc 26 <file:Documentation/filesystems/proc.rst> and on the proc(5) manpage
27 ("man 5 proc"). 27 ("man 5 proc").
28 28
29 This option will enlarge your kernel 29 This option will enlarge your kernel by about 67 KB. Several
30 programs depend on this, so everyone 30 programs depend on this, so everyone should say Y here.
31 31
32 config PROC_KCORE 32 config PROC_KCORE
33 bool "/proc/kcore support" if !ARM 33 bool "/proc/kcore support" if !ARM
34 depends on PROC_FS && MMU 34 depends on PROC_FS && MMU
35 select VMCORE_INFO !! 35 select CRASH_CORE
36 help 36 help
37 Provides a virtual ELF core file of 37 Provides a virtual ELF core file of the live kernel. This can
38 be read with gdb and other ELF tools 38 be read with gdb and other ELF tools. No modifications can be
39 made using this mechanism. 39 made using this mechanism.
40 40
41 config PROC_VMCORE 41 config PROC_VMCORE
42 bool "/proc/vmcore support" 42 bool "/proc/vmcore support"
43 depends on PROC_FS && CRASH_DUMP 43 depends on PROC_FS && CRASH_DUMP
44 default y 44 default y
45 help 45 help
46 Exports the dump image of crashed ke 46 Exports the dump image of crashed kernel in ELF format.
47 47
48 config PROC_VMCORE_DEVICE_DUMP 48 config PROC_VMCORE_DEVICE_DUMP
49 bool "Device Hardware/Firmware Log Col 49 bool "Device Hardware/Firmware Log Collection"
50 depends on PROC_VMCORE 50 depends on PROC_VMCORE
51 default n 51 default n
52 help 52 help
53 After kernel panic, device drivers c 53 After kernel panic, device drivers can collect the device
54 specific snapshot of their hardware 54 specific snapshot of their hardware or firmware before the
55 underlying devices are initialized i 55 underlying devices are initialized in crash recovery kernel.
56 Note that the device driver must be 56 Note that the device driver must be present in the crash
57 recovery kernel's initramfs to colle 57 recovery kernel's initramfs to collect its underlying device
58 snapshot. 58 snapshot.
59 59
60 If you say Y here, the collected dev 60 If you say Y here, the collected device dumps will be added
61 as ELF notes to /proc/vmcore. You ca 61 as ELF notes to /proc/vmcore. You can still disable device
62 dump using the kernel command line o 62 dump using the kernel command line option 'novmcoredd'.
63 63
64 config PROC_SYSCTL 64 config PROC_SYSCTL
65 bool "Sysctl support (/proc/sys)" if E 65 bool "Sysctl support (/proc/sys)" if EXPERT
66 depends on PROC_FS 66 depends on PROC_FS
67 select SYSCTL 67 select SYSCTL
68 default y 68 default y
69 help 69 help
70 The sysctl interface provides a mean 70 The sysctl interface provides a means of dynamically changing
71 certain kernel parameters and variab 71 certain kernel parameters and variables on the fly without requiring
72 a recompile of the kernel or reboot 72 a recompile of the kernel or reboot of the system. The primary
73 interface is through /proc/sys. If 73 interface is through /proc/sys. If you say Y here a tree of
74 modifiable sysctl entries will be ge 74 modifiable sysctl entries will be generated beneath the
75 /proc/sys directory. They are explai 75 /proc/sys directory. They are explained in the files
76 in <file:Documentation/admin-guide/s 76 in <file:Documentation/admin-guide/sysctl/>. Note that enabling this
77 option will enlarge the kernel by at 77 option will enlarge the kernel by at least 8 KB.
78 78
79 As it is generally a good thing, you 79 As it is generally a good thing, you should say Y here unless
80 building a kernel for install/rescue 80 building a kernel for install/rescue disks or your system is very
81 limited in memory. 81 limited in memory.
82 82
83 config PROC_PAGE_MONITOR 83 config PROC_PAGE_MONITOR
84 default y 84 default y
85 depends on PROC_FS && MMU 85 depends on PROC_FS && MMU
86 bool "Enable /proc page monitoring" if 86 bool "Enable /proc page monitoring" if EXPERT
87 help 87 help
88 Various /proc files exist to monitor 88 Various /proc files exist to monitor process memory utilization:
89 /proc/pid/smaps, /proc/pid/clear_ref 89 /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
90 /proc/kpagecount, and /proc/kpagefla 90 /proc/kpagecount, and /proc/kpageflags. Disabling these
91 interfaces will reduce the size of t 91 interfaces will reduce the size of the kernel by approximately 4kb.
92 92
93 config PROC_CHILDREN 93 config PROC_CHILDREN
94 bool "Include /proc/<pid>/task/<tid>/c 94 bool "Include /proc/<pid>/task/<tid>/children file"
95 depends on PROC_FS <<
96 default n 95 default n
97 help 96 help
98 Provides a fast way to retrieve firs 97 Provides a fast way to retrieve first level children pids of a task. See
99 <file:Documentation/filesystems/proc 98 <file:Documentation/filesystems/proc.rst> for more information.
100 99
101 Say Y if you are running any user-sp 100 Say Y if you are running any user-space software which takes benefit from
102 this interface. For example, rkt is 101 this interface. For example, rkt is such a piece of software.
103 102
104 config PROC_PID_ARCH_STATUS 103 config PROC_PID_ARCH_STATUS
105 def_bool n 104 def_bool n
106 depends on PROC_FS 105 depends on PROC_FS
107 106
108 config PROC_CPU_RESCTRL 107 config PROC_CPU_RESCTRL
109 def_bool n 108 def_bool n
110 depends on PROC_FS 109 depends on PROC_FS
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