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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2012-04-26 13:12:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-05-09 15:00:49 +0200 |
| commit | c82513e513556a04f81aa511cd890acd23349c48 (patch) | |
| tree | dbccd379fffd75cd87513e4dd0e91ac597628382 /kernel/sched/sched.h | |
| parent | ad7687dde8780a0d618a3e3b5a62bb383696fc22 (diff) | |
| download | linux-c82513e513556a04f81aa511cd890acd23349c48.tar.gz linux-c82513e513556a04f81aa511cd890acd23349c48.tar.bz2 linux-c82513e513556a04f81aa511cd890acd23349c48.zip | |
sched: Change rq->nr_running to unsigned int
Since there's a PID space limit of 30bits (see
futex.h:FUTEX_TID_MASK) and allocating that many tasks (assuming a
lower bound of 2 pages per task) would still take 8T of memory it
seems reasonable to say that unsigned int is sufficient for
rq->nr_running.
When we do get anywhere near that amount of tasks I suspect other
things would go funny, load-balancer load computations would really
need to be hoisted to 128bit etc.
So save a few bytes and convert rq->nr_running and friends to
unsigned int.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-y3tvyszjdmbibade5bw8zl81@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/sched.h')
| -rw-r--r-- | kernel/sched/sched.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index fb3acba4d52e..7282e7b5f4c7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -201,7 +201,7 @@ struct cfs_bandwidth { }; /* CFS-related fields in a runqueue */ struct cfs_rq { struct load_weight load; - unsigned long nr_running, h_nr_running; + unsigned int nr_running, h_nr_running; u64 exec_clock; u64 min_vruntime; @@ -279,7 +279,7 @@ static inline int rt_bandwidth_enabled(void) /* Real-Time classes' related field in a runqueue: */ struct rt_rq { struct rt_prio_array active; - unsigned long rt_nr_running; + unsigned int rt_nr_running; #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED struct { int curr; /* highest queued rt task prio */ @@ -353,7 +353,7 @@ struct rq { * nr_running and cpu_load should be in the same cacheline because * remote CPUs use both these fields when doing load calculation. */ - unsigned long nr_running; + unsigned int nr_running; #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; unsigned long last_load_update_tick; |