[PATCH v2 0/2] Replace PID bitmap allocation with IDR API

Gargi Sharma
2017-09-27T05:06:20Z

This patch series replaces kernel bitmap implementation of PID allocation
with IDR API. These patches are written to simplify the kernel by replacing custom code with calls to generic code.

The following are the stats for pid and pid_namespace object files
before and after the replacement. There is a noteworthy change between
the IDR and bitmap implementation.

Before
text data bss dec hex filename
8447 3894 64 12405 3075 kernel/pid.o
After
text data bss dec hex filename
3301 304 0 3605 e15 kernel/pid.o

Before
text data bss dec hex filename
5692 1842 192 7726 1e2e kernel/pid_namespace.o
After
text data bss dec hex filename
2870 216 16 3102 c1e kernel/pid_namespace.o

There wasn't a considerable difference between the time required for
allocation of PIDs to the processes.

---
Changes in v2:
- Removed redundant IDR function that was introduced
in the previous patchset.
- Renamed PIDNS_HASH_ADDING
- Used idr_for_each_entry_continue()
- Used idr_find() to lookup pids

Gargi Sharma (2):
pid: Replace pid bitmap implementation with IDR API
pid: Remove pidhash

arch/powerpc/platforms/cell/spufs/sched.c | 2 +-
fs/proc/loadavg.c | 2 +-
include/linux/init_task.h | 1 -
include/linux/pid.h | 2 -
include/linux/pid_namespace.h | 18 +--
init/main.c | 3 +-
kernel/fork.c | 2 +-
kernel/pid.c | 239 +++++-------------------------
kernel/pid_namespace.c | 54 +++----
9 files changed, 68 insertions(+), 255 deletions(-)

--
2.7.4