From e669ac8ab952df2f07dee1e1efbf40647d6de332 Mon Sep 17 00:00:00 2001 From: Valentin Schneider Date: Wed, 15 Apr 2020 22:05:06 +0100 Subject: sched: Remove checks against SD_LOAD_BALANCE The SD_LOAD_BALANCE flag is set unconditionally for all domains in sd_init(). By making the sched_domain->flags syctl interface read-only, we have removed the last piece of code that could clear that flag - as such, it will now be always present. Rather than to keep carrying it along, we can work towards getting rid of it entirely. cpusets don't need it because they can make CPUs be attached to the NULL domain (e.g. cpuset with sched_load_balance=0), or to a partitioned root_domain, i.e. a sched_domain hierarchy that doesn't span the entire system (e.g. root cpuset with sched_load_balance=0 and sibling cpusets with sched_load_balance=1). isolcpus apply the same "trick": isolated CPUs are explicitly taken out of the sched_domain rebuild (using housekeeping_cpumask()), so they get the NULL domain treatment as well. Remove the checks against SD_LOAD_BALANCE. Signed-off-by: Valentin Schneider Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200415210512.805-4-valentin.schneider@arm.com --- kernel/sched/topology.c | 28 +++++++++------------------- 1 file changed, 9 insertions(+), 19 deletions(-) (limited to 'kernel/sched/topology.c') diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8344757bba6e..a9dc34a0ebc1 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -33,14 +33,6 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, cpumask_clear(groupmask); printk(KERN_DEBUG "%*s domain-%d: ", level, "", level); - - if (!(sd->flags & SD_LOAD_BALANCE)) { - printk("does not load-balance\n"); - if (sd->parent) - printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain has parent"); - return -1; - } - printk(KERN_CONT "span=%*pbl level=%s\n", cpumask_pr_args(sched_domain_span(sd)), sd->name); @@ -151,8 +143,7 @@ static int sd_degenerate(struct sched_domain *sd) return 1; /* Following flags need at least 2 groups */ - if (sd->flags & (SD_LOAD_BALANCE | - SD_BALANCE_NEWIDLE | + if (sd->flags & (SD_BALANCE_NEWIDLE | SD_BALANCE_FORK | SD_BALANCE_EXEC | SD_SHARE_CPUCAPACITY | @@ -183,15 +174,14 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) /* Flags needing groups don't count if only 1 group in parent */ if (parent->groups == parent->groups->next) { - pflags &= ~(SD_LOAD_BALANCE | - SD_BALANCE_NEWIDLE | - SD_BALANCE_FORK | - SD_BALANCE_EXEC | - SD_ASYM_CPUCAPACITY | - SD_SHARE_CPUCAPACITY | - SD_SHARE_PKG_RESOURCES | - SD_PREFER_SIBLING | - SD_SHARE_POWERDOMAIN); + pflags &= ~(SD_BALANCE_NEWIDLE | + SD_BALANCE_FORK | + SD_BALANCE_EXEC | + SD_ASYM_CPUCAPACITY | + SD_SHARE_CPUCAPACITY | + SD_SHARE_PKG_RESOURCES | + SD_PREFER_SIBLING | + SD_SHARE_POWERDOMAIN); if (nr_node_ids == 1) pflags &= ~SD_SERIALIZE; } -- cgit