Documentation/filesystems/proc.rst: copy-editing cleanup
Clean up Documentation/filesystems/proc.rst.
This is basically fixing lots of spelling, grammar, punctuation,
typos, spacing, consistency, section numbering, and headings.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/a5f126e6-d67a-154a-1c87-d8f07542a21c@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index cc0fd26..e024a9e 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -123,10 +123,10 @@
The directory /proc contains (among other things) one subdirectory for each
process running on the system, which is named after the process ID (PID).
-The link self points to the process reading the file system. Each process
+The link 'self' points to the process reading the file system. Each process
subdirectory has the entries listed in Table 1-1.
-Note that an open a file descriptor to /proc/<pid> or to any of its
+Note that an open file descriptor to /proc/<pid> or to any of its
contained files or subdirectories does not prevent <pid> being reused
for some other process in the event that <pid> exits. Operations on
open /proc/<pid> file descriptors corresponding to dead processes
@@ -220,7 +220,7 @@
The statm file contains more detailed information about the process
memory usage. Its seven fields are explained in Table 1-3. The stat file
-contains details information about the process itself. Its fields are
+contains detailed information about the process itself. Its fields are
explained in Table 1-4.
(for SMP CONFIG users)
@@ -782,7 +782,7 @@
For this case the APIC will generate the interrupt with a IRQ vector
of 0xff. This might also be generated by chipset bugs.
-RES, CAL, TLB]
+RES, CAL, TLB
rescheduling, call and TLB flush interrupts are
sent from one CPU to another per the needs of the OS. Typically,
their statistics are used by kernel developers and interested users to
@@ -794,7 +794,7 @@
i386 and x86_64 platforms support the new IRQ vector displays.
Of some interest is the introduction of the /proc/irq directory to 2.4.
-It could be used to set IRQ to CPU affinity, this means that you can "hook" an
+It could be used to set IRQ to CPU affinity. This means that you can "hook" an
IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the
irq subdir is one subdir for each IRQ, and two files; default_smp_affinity and
prof_cpu_mask.
@@ -808,7 +808,7 @@
smp_affinity
smp_affinity is a bitmask, in which you can specify which CPUs can handle the
-IRQ, you can set it by doing::
+IRQ. You can set it by doing::
> echo 1 > /proc/irq/10/smp_affinity
@@ -821,7 +821,7 @@
ffffffff
There is an alternate interface, smp_affinity_list which allows specifying
-a cpu range instead of a bitmask::
+a CPU range instead of a bitmask::
> cat /proc/irq/0/smp_affinity_list
1024-1031
@@ -835,7 +835,7 @@
include information about any possible driver locality preference.
prof_cpu_mask specifies which CPUs are to be profiled by the system wide
-profiler. Default value is ffffffff (all cpus if there are only 32 of them).
+profiler. Default value is ffffffff (all CPUs if there are only 32 of them).
The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
between all the CPUs which are allowed to handle it. As usual the kernel has
@@ -897,7 +897,7 @@
Fragmentation avoidance in the kernel works by grouping pages of different
migrate types into the same contiguous regions of memory called page blocks.
-A page block is typically the size of the default hugepage size e.g. 2MB on
+A page block is typically the size of the default hugepage size, e.g. 2MB on
X86-64. By keeping pages grouped based on their ability to move, the kernel
can reclaim pages within a page block to satisfy a high-order allocation.
@@ -965,7 +965,7 @@
ShmemPmdMapped: 0 kB
MemTotal
- Total usable ram (i.e. physical ram minus a few reserved
+ Total usable RAM (i.e. physical RAM minus a few reserved
bits and the kernel binary code)
MemFree
The sum of LowFree+HighFree
@@ -996,7 +996,7 @@
Memory which has been less recently used. It is more
eligible to be reclaimed for other purposes
HighTotal, HighFree
- Highmem is all memory above ~860MB of physical memory
+ Highmem is all memory above ~860MB of physical memory.
Highmem areas are for use by userspace programs, or
for the pagecache. The kernel must use tricks to access
this memory, making it slower to access than lowmem.
@@ -1078,7 +1078,7 @@
using 1G. This 1G is memory which has been "committed" to
by the VM and can be used at any time by the allocating
application. With strict overcommit enabled on the system
- (mode 2 in 'vm.overcommit_memory'),allocations which would
+ (mode 2 in 'vm.overcommit_memory'), allocations which would
exceed the CommitLimit (detailed above) will not be permitted.
This is useful if one needs to guarantee that processes will
not fail due to lack of memory once that memory has been
@@ -1099,7 +1099,7 @@
Provides information about vmalloced/vmaped areas. One line per area,
containing the virtual address range of the area, size in bytes,
caller information of the creator, and optional information depending
-on the kind of area :
+on the kind of area:
========== ===================================================
pages=nr number of pages
@@ -1144,21 +1144,21 @@
softirqs
~~~~~~~~
-Provides counts of softirq handlers serviced since boot time, for each cpu.
+Provides counts of softirq handlers serviced since boot time, for each CPU.
::
> cat /proc/softirqs
- CPU0 CPU1 CPU2 CPU3
+ CPU0 CPU1 CPU2 CPU3
HI: 0 0 0 0
- TIMER: 27166 27120 27097 27034
+ TIMER: 27166 27120 27097 27034
NET_TX: 0 0 0 17
NET_RX: 42 0 0 39
- BLOCK: 0 0 107 1121
- TASKLET: 0 0 0 290
- SCHED: 27035 26983 26971 26746
- HRTIMER: 0 0 0 0
- RCU: 1678 1769 2178 2250
+ BLOCK: 0 0 107 1121
+ TASKLET: 0 0 0 290
+ SCHED: 27035 26983 26971 26746
+ HRTIMER: 0 0 0 0
+ RCU: 1678 1769 2178 2250
1.3 IDE devices in /proc/ide
@@ -1169,7 +1169,7 @@
file drivers and a link for each IDE device, pointing to the device directory
in the controller specific subtree.
-The file drivers contains general information about the drivers used for the
+The file 'drivers' contains general information about the drivers used for the
IDE devices::
> cat /proc/ide/drivers
@@ -1409,7 +1409,7 @@
-------------------------
Information about the available and actually used tty's can be found in the
-directory /proc/tty.You'll find entries for drivers and line disciplines in
+directory /proc/tty. You'll find entries for drivers and line disciplines in
this directory, as shown in Table 1-11.
@@ -1471,9 +1471,9 @@
- iowait: In a word, iowait stands for waiting for I/O to complete. But there
are several problems:
- 1. Cpu will not wait for I/O to complete, iowait is the time that a task is
- waiting for I/O to complete. When cpu goes into idle state for
- outstanding task io, another task will be scheduled on this CPU.
+ 1. CPU will not wait for I/O to complete, iowait is the time that a task is
+ waiting for I/O to complete. When CPU goes into idle state for
+ outstanding task I/O, another task will be scheduled on this CPU.
2. In a multi-core CPU, the task waiting for I/O to complete is not running
on any CPU, so the iowait of each CPU is difficult to calculate.
3. The value of iowait field in /proc/stat will decrease in certain
@@ -1529,8 +1529,8 @@
mb_groups details of multiblock allocator buddy cache of free blocks
============== ==========================================================
-2.0 /proc/consoles
-------------------
+1.10 /proc/consoles
+-------------------
Shows registered system console lines.
To see which character device lines are currently used for the system console
@@ -1590,10 +1590,9 @@
everything works the way you want it to. You may have no alternative but to
reboot the machine once an error has been made.
-To change a value, simply echo the new value into the file. An example is
-given below in the section on the file system data. You need to be root to do
-this. You can create your own boot script to perform this every time your
-system boots.
+To change a value, simply echo the new value into the file.
+You need to be root to do this. You can create your own boot script
+to perform this every time your system boots.
The files in /proc/sys can be used to fine tune and monitor miscellaneous and
general things in the operation of the Linux kernel. Since some of the files
@@ -1624,8 +1623,8 @@
3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score
--------------------------------------------------------------------------------
-These file can be used to adjust the badness heuristic used to select which
-process gets killed in out of memory conditions.
+These files can be used to adjust the badness heuristic used to select which
+process gets killed in out of memory (oom) conditions.
The badness heuristic assigns a value to each candidate task ranging from 0
(never kill) to 1000 (always kill) to determine which process is targeted. The
@@ -1681,7 +1680,7 @@
3.2 /proc/<pid>/oom_score - Display current oom-killer score
-------------------------------------------------------------
-This file can be used to check the current score used by the oom-killer is for
+This file can be used to check the current score used by the oom-killer for
any given <pid>. Use it together with /proc/<pid>/oom_score_adj to tune which
process should be killed in an out-of-memory situation.
@@ -1689,7 +1688,7 @@
3.3 /proc/<pid>/io - Display the IO accounting fields
-------------------------------------------------------
-This file contains IO statistics for each running process
+This file contains IO statistics for each running process.
Example
~~~~~~~
@@ -1720,7 +1719,7 @@
is simply the sum of bytes which this process passed to read() and pread().
It includes things like tty IO and it is unaffected by whether or not actual
physical disk IO was required (the read might have been satisfied from
-pagecache)
+pagecache).
wchar
@@ -1878,7 +1877,7 @@
3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
--------------------------------------------------------
-These files provide a method to access a tasks comm value. It also allows for
+These files provide a method to access a task's comm value. It also allows for
a task to set its own or one of its thread siblings comm value. The comm value
is limited in size compared to the cmdline value, so writing anything longer
then the kernel's TASK_COMM_LEN (currently 16 chars) will result in a truncated
@@ -1891,21 +1890,21 @@
of a task pointed by <pid>/<tid> pair. The format is a space separated
stream of pids.
-Note the "first level" here -- if a child has own children they will
-not be listed here, one needs to read /proc/<children-pid>/task/<tid>/children
+Note the "first level" here -- if a child has its own children they will
+not be listed here; one needs to read /proc/<children-pid>/task/<tid>/children
to obtain the descendants.
Since this interface is intended to be fast and cheap it doesn't
guarantee to provide precise results and some children might be
skipped, especially if they've exited right after we printed their
-pids, so one need to either stop or freeze processes being inspected
+pids, so one needs to either stop or freeze processes being inspected
if precise results are needed.
3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
---------------------------------------------------------------
This file provides information associated with an opened file. The regular
-files have at least three fields -- 'pos', 'flags' and mnt_id. The 'pos'
+files have at least three fields -- 'pos', 'flags' and 'mnt_id'. The 'pos'
represents the current offset of the opened file in decimal form [see lseek(2)
for details], 'flags' denotes the octal O_xxx mask the file has been
created with [see open(2) for details] and 'mnt_id' represents mount ID of
@@ -1976,7 +1975,7 @@
flags: 02000000
inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
-where 'wd' is a watch descriptor in decimal form, ie a target file
+where 'wd' is a watch descriptor in decimal form, i.e. a target file
descriptor number, 'ino' and 'sdev' are inode and device where the
target file resides and the 'mask' is the mask of events, all in hex
form [see inotify(7) for more details].
@@ -2003,10 +2002,10 @@
where fanotify 'flags' and 'event-flags' are values used in fanotify_init
call, 'mnt_id' is the mount point identifier, 'mflags' is the value of
flags associated with mark which are tracked separately from events
-mask. 'ino', 'sdev' are target inode and device, 'mask' is the events
+mask. 'ino' and 'sdev' are target inode and device, 'mask' is the events
mask and 'ignored_mask' is the mask of events which are to be ignored.
-All in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask'
-does provide information about flags and mask used in fanotify_mark
+All are in hex format. Incorporation of 'mflags', 'mask' and 'ignored_mask'
+provide information about flags and mask used in fanotify_mark
call [see fsnotify manpage for details].
While the first three lines are mandatory and always printed, the rest is
@@ -2029,7 +2028,7 @@
where 'clockid' is the clock type and 'ticks' is the number of the timer expirations
that have occurred [see timerfd_create(2) for details]. 'settime flags' are
flags in octal form been used to setup the timer [see timerfd_settime(2) for
-details]. 'it_value' is remaining time until the timer exiration.
+details]. 'it_value' is remaining time until the timer expiration.
'it_interval' is the interval for the timer. Note the timer might be set up
with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value'
still exhibits timer's remaining time.
@@ -2059,13 +2058,13 @@
3.10 /proc/<pid>/timerslack_ns - Task timerslack value
---------------------------------------------------------
This file provides the value of the task's timerslack value in nanoseconds.
-This value specifies a amount of time that normal timers may be deferred
+This value specifies an amount of time that normal timers may be deferred
in order to coalesce timers and avoid unnecessary wakeups.
-This allows a task's interactivity vs power consumption trade off to be
+This allows a task's interactivity vs power consumption tradeoff to be
adjusted.
-Writing 0 to the file will set the tasks timerslack to the default value.
+Writing 0 to the file will set the task's timerslack to the default value.
Valid values are from 0 - ULLONG_MAX
@@ -2105,10 +2104,10 @@
Description
~~~~~~~~~~~
-x86 specific entries:
+x86 specific entries
~~~~~~~~~~~~~~~~~~~~~
-AVX512_elapsed_ms:
+AVX512_elapsed_ms
^^^^^^^^^^^^^^^^^^
If AVX512 is supported on the machine, this entry shows the milliseconds
@@ -2134,8 +2133,8 @@
the task is unlikely an AVX512 user, but depends on the workload and the
scheduling scenario, it also could be a false negative mentioned above.
-Configuring procfs
-------------------
+Chapter 4: Configuring procfs
+=============================
4.1 Mount options
---------------------
@@ -2178,8 +2177,8 @@
subset=pid hides all top level files and directories in the procfs that
are not related to tasks.
-5 Filesystem behavior
----------------------------
+Chapter 5: Filesystem behavior
+==============================
Originally, before the advent of pid namepsace, procfs was a global file
system. It means that there was only one procfs instance in the system.