core: Global timer-wheel

Instantiate a process wide global instance of the timer wheel
data structure. Spawning glusterfs* process with option arg
"--global-timer-wheel" instantiates a global instance of
timer-wheel under global context (->ctx).

Translators can make use of this process wide instance [via a
call to glusterfs_global_timer_wheel()] instead of maintaining
an instance of their own and possibly consuming more memory.
Linux kernel too has a single instance of timer wheel where
subsystems such as IO, networking, etc.. make use of.

Bitrot daemon would be early consumers of this: bitrot translator
instances for multiple volumes would track objects belonging to
their respective bricks in this global expiry tracking data
structure. This is also a first step to move GlusterFS timer
mechanism to use timer-wheel.

> Change-Id: Ie882df607e07acaced846ea269ebf1ece306d6ae
> BUG: 1170075
> Signed-off-by: Venky Shankar <vshankar@redhat.com>
> Reviewed-on: http://review.gluster.org/10380
> Tested-by: NetBSD Build System
> Reviewed-by: Vijay Bellur <vbellur@redhat.com>
> Tested-by: Gluster Build System <jenkins@build.gluster.com>

Change-Id: I35c840daa9996a059699f8ea5af54c76ede7e09c
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Gaurav Kumar Garg <ggarg@redhat.com>
BUG: 1220041
Reviewed-on: http://review.gluster.org/10716
Tested-by: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/glusterfsd/src/glusterfsd.h b/glusterfsd/src/glusterfsd.h
index a16e0a65254..d183b0507fa 100644
--- a/glusterfsd/src/glusterfsd.h
+++ b/glusterfsd/src/glusterfsd.h
@@ -94,6 +94,7 @@ enum argp_option_keys {
         ARGP_LOG_BUF_SIZE                 = 170,
         ARGP_LOG_FLUSH_TIMEOUT            = 171,
         ARGP_SECURE_MGMT_KEY              = 172,
+        ARGP_GLOBAL_TIMER_WHEEL           = 173,
 };
 
 struct _gfd_vol_top_priv_t {