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Subject[PATCH 1/1] kernel/pid.c: Improve flow of a loop inside alloc_pidmap.
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From: Raphael S.Carvalho <raphael.scarv@gmail.com>

Notes: find_next_offset searches for an available "cleaned bit"
in the respective pid bitmap (page), so returns the offset if found,
otherwise it returns a value equals to BITS_PER_PAGE.

For example, suppose find_next_offset didn't find any available
bit, so there's no purpose to call mk_pid (Wasteful Cpu Cycles).

Therefore, I found it could be better to call mk_pid after
the checking (offset < BITS_PER_PAGE) returned sucessfully!
Another point: If (offset < BITS_PER_PAGE) results in a "failure",
then mk_pid would be called again afterwards.

Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com>
---
kernel/pid.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/pid.c b/kernel/pid.c
index 047dc62..7ecb09a 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -190,8 +190,8 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
return pid;
}
offset = find_next_offset(map, offset);
- pid = mk_pid(pid_ns, map, offset);
- } while (offset < BITS_PER_PAGE && pid < pid_max);
+ } while (offset < BITS_PER_PAGE &&
+ (pid = mk_pid(pid_ns, map, offset)) < pid_max);
}
if (map < &pid_ns->pidmap[(pid_max-1)/BITS_PER_PAGE]) {
++map;
--
1.7.2.5


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