glusterfs.git/libglusterfs/src/tw.h, branch v5.13 core: make the per glusterfs_ctx_t timer-wheel refcounted 2017-05-01T09:30:14+00:00 Niels de Vos ndevos@redhat.com 2017-04-17T10:20:07+00:00 73fcf3a874b2049da31d01b8363d1ac85c9488c2 xlators can use a 'global' timer-wheel for scheduling events. This timer-wheel is managed per glusterfs_ctx_t, but does not need to be allocated for every graph. When an xlator wants to use the timer-wheel, it will be instanciated on demand, and provided to xlators that request it later on. By adding a reference counter to the glusterfs_ctx_t for the timer-wheel, the threads and structures can be cleaned up when the last xlator does not have a need for it anymore. In general, the xlators request the timer-wheel in init(), and they should return it in fini(). Because the timer-wheel is managed per glusterfs_ctx_t, the functions can be added to ctx.c and do not need to live in their very minimal tw.[ch] files. Change-Id: I19d225b39aaa272d9005ba7adc3104c3764f1572 BUG: 1442788 Reported-by: Poornima G <pgurusid@redhat.com> Signed-off-by: Niels de Vos <ndevos@redhat.com> Reviewed-on: https://review.gluster.org/17068 NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org> CentOS-regression: Gluster Build System <jenkins@build.gluster.org> Smoke: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Amar Tumballi <amarts@redhat.com> Reviewed-by: Zhou Zhengping <johnzzpcrystal@gmail.com> Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com> 
xlators can use a 'global' timer-wheel for scheduling events. This
timer-wheel is managed per glusterfs_ctx_t, but does not need to be
allocated for every graph. When an xlator wants to use the timer-wheel,
it will be instanciated on demand, and provided to xlators that request
it later on.

By adding a reference counter to the glusterfs_ctx_t for the
timer-wheel, the threads and structures can be cleaned up when the last
xlator does not have a need for it anymore. In general, the xlators
request the timer-wheel in init(), and they should return it in fini().

Because the timer-wheel is managed per glusterfs_ctx_t, the functions
can be added to ctx.c and do not need to live in their very minimal
tw.[ch] files.

Change-Id: I19d225b39aaa272d9005ba7adc3104c3764f1572
BUG: 1442788
Reported-by: Poornima G <pgurusid@redhat.com>
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: https://review.gluster.org/17068
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Reviewed-by: Zhou Zhengping <johnzzpcrystal@gmail.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
core: Global timer-wheel 2015-04-26T18:04:11+00:00 Venky Shankar vshankar@redhat.com 2015-04-24T04:40:35+00:00 004f64e93d23f44144483d21422f47e81d358045 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> 
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>