BackPup/Linux
1
0 Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-10-07 22:37:45 -04:00
Code Issues Packages Projects Releases Wiki Activity

sched/topology: Remove the ::smt_gain field from 'struct sched_domain'

Browse Source 
::smt_gain is used to compute the capacity of CPUs of a SMT core with the
constraint 1 < ::smt_gain < 2 in order to be able to compute number of CPUs
per core. The field has_free_capacity of struct numa_stat, which was the
last user of this computation of number of CPUs per core, has been removed
by:

  2d4056fafa ("sched/numa: Remove numa_has_capacity()")

We can now remove this constraint on core capacity and use the defautl value
SCHED_CAPACITY_SCALE for SMT CPUs. With this remove, SCHED_CAPACITY_SCALE
becomes the maximum compute capacity of CPUs on every systems. This should
help to simplify some code and remove fields like rd->max_cpu_capacity

Furthermore, arch_scale_cpu_capacity() is used with a NULL sd in several other
places in the code when it wants the capacity of a CPUs to scale
some metrics like in pelt, deadline or schedutil. In case on SMT, the value
returned is not the capacity of SMT CPUs but default SCHED_CAPACITY_SCALE.

So remove it.

Signed-off-by: Vincent Guittot <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Vincent Guittot authored and Ingo Molnar committed 2018-12-11 15:16:57 +01:00
1 parent dfcb245e28
commit 765d0af19f
3 files changed
-6
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

include/linux/sched/topology.h
-1
View File
@@ -89,7 +89,6 @@ struct sched_domain {
unsigned int newidle_idx;
unsigned int wake_idx;
unsigned int forkexec_idx;
unsigned int smt_gain;
int nohz_idle; /* NOHZ IDLE status */
int flags; /* See SD_* */
kernel/sched/sched.h
-3
View File
@@ -1864,9 +1864,6 @@ unsigned long arch_scale_freq_capacity(int cpu)
static __always_inline
unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
{
if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
return sd->smt_gain / sd->span_weight;
return SCHED_CAPACITY_SCALE;
}
#endif
kernel/sched/topology.c
-2
View File
@@ -1133,7 +1133,6 @@ sd_init(struct sched_domain_topology_level *tl,
.last_balance = jiffies,
.balance_interval = sd_weight,
.smt_gain = 0,
.max_newidle_lb_cost = 0,
.next_decay_max_lb_cost = jiffies,
.child = child,
@@ -1164,7 +1163,6 @@ sd_init(struct sched_domain_topology_level *tl,
if (sd->flags & SD_SHARE_CPUCAPACITY) {
sd->imbalance_pct = 110;
sd->smt_gain = 1178; /* ~15% */
} else if (sd->flags & SD_SHARE_PKG_RESOURCES) {
sd->imbalance_pct = 117;