[PATCH 1/5] include: linux: pid: Update documentation.

* [PATCH 1/5] include: linux: pid: Update documentation.
       [not found] <cover.1490516333.git.rvarsha016@gmail.com>
@ 2017-03-26 10:04 ` Varsha Rao
  2017-03-26 10:49   ` [Outreachy kernel] " Julia Lawall
  2017-03-26 10:05 ` [PATCH 2/5] include: linux: pid: Move open brace to previous line Varsha Rao
                   ` (3 subsequent siblings)
  4 siblings, 1 reply; 8+ messages in thread
From: Varsha Rao @ 2017-03-26 10:04 UTC (permalink / raw)
  To: mawilcox; +Cc: outreachy-kernel

This patch adds comments to update documentation. Also remove extra
space between full stop and and new sentence, of existing comments.

Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
---
 include/linux/pid.h | 43 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 11 deletions(-)

diff --git a/include/linux/pid.h b/include/linux/pid.h
index 4d17931..c2bea47 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -5,32 +5,32 @@
 
 enum pid_type
 {
-	PIDTYPE_PID,
-	PIDTYPE_PGID,
-	PIDTYPE_SID,
-	PIDTYPE_MAX
+	PIDTYPE_PID, /* Process ID */
+	PIDTYPE_PGID, /* Process group ID */
+	PIDTYPE_SID, /* Process session ID */
+	PIDTYPE_MAX /* Number of ID types */
 };
 
 /*
  * What is struct pid?
  *
  * A struct pid is the kernel's internal notion of a process identifier.
- * It refers to individual tasks, process groups, and sessions.  While
+ * It refers to individual tasks, process groups, and sessions. While
  * there are processes attached to it the struct pid lives in a hash
  * table, so it and then the processes that it refers to can be found
- * quickly from the numeric pid value.  The attached processes may be
+ * quickly from the numeric pid value. The attached processes may be
  * quickly accessed by following pointers from struct pid.
  *
  * Storing pid_t values in the kernel and referring to them later has a
- * problem.  The process originally with that pid may have exited and the
+ * problem. The process originally with that pid may have exited and the
  * pid allocator wrapped, and another process could have come along
  * and been assigned that pid.
  *
  * Referring to user space processes by holding a reference to struct
- * task_struct has a problem.  When the user space process exits
- * the now useless task_struct is still kept.  A task_struct plus a
- * stack consumes around 10K of low kernel memory.  More precisely
- * this is THREAD_SIZE + sizeof(struct task_struct).  By comparison
+ * task_struct has a problem. When the user space process exits
+ * the now useless task_struct is still kept. A task_struct plus a
+ * stack consumes around 10K of low kernel memory. More precisely
+ * this is THREAD_SIZE + sizeof(struct task_struct). By comparison
  * a struct pid is about 64 bytes.
  *
  * Holding a reference to struct pid solves both of these problems.
@@ -45,6 +45,10 @@ enum pid_type
  * struct upid is used to get the id of the struct pid, as it is
  * seen in particular namespace. Later the struct pid is found with
  * find_pid_ns() using the int nr and struct pid_namespace *ns.
+ *
+ * @nr: Pid value.
+ * @ns: Represents the namespace to which pid value belongs.
+ * @pid_chain: Hash chain.
  */
 
 struct upid {
@@ -54,6 +58,15 @@ struct upid {
 	struct hlist_node pid_chain;
 };
 
+/*
+ * struct pid
+ * @count: Reference counter.
+ * @level: Number of namespaces in which the process is visible.
+ * @tasks: Lists of tasks.
+ * @rcu: RCU helper.
+ * @numbers: Instance of upid for each level.
+ */
+
 struct pid
 {
 	atomic_t count;
@@ -66,12 +79,20 @@ struct pid
 
 extern struct pid init_struct_pid;
 
+/*
+ * struct pid_link is used for per process linkage into hash tables.
+ * @node: List element.
+ * @pid: Pointer to the struct pid of the process.
+ */
 struct pid_link
 {
 	struct hlist_node node;
 	struct pid *pid;
 };
 
+/* get_pid() checks availability of process id and if available assigns
+ * process ID.
+ */
 static inline struct pid *get_pid(struct pid *pid)
 {
 	if (pid)
-- 
2.9.3



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