Messages in this thread | | | Date | Wed, 26 Nov 2014 08:34:32 +0800 | From | Wanpeng Li <> | Subject | Re: [PATCH v6 1/7] sched/deadline: fix start high-res preemption tick for a non-leftmost task |
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Replace the subject by "Subject: [PATCH v6 2/7] sched/deadline: fix rt runtime corrupt when dl refuse a smaller bandwidth" On Wed, Nov 26, 2014 at 08:44:02AM +0800, Wanpeng Li wrote: >Dl class will refuse the bandwidth being set to some value smaller >than the currently allocated bandwidth in any of the root_domains >through sched_rt_runtime_us and sched_rt_period_us. RT runtime will >be set according to sched_rt_runtime_us before dl class verify if >the new bandwidth is suitable in the case of !CONFIG_RT_GROUP_SCHED. > >However, rt runtime will be corrupt if dl refuse the new bandwidth >since there is no undo to reset the rt runtime to the old value. > >This patch fix it by verifying new bandwidth for deadline in advance. > >Cc: Juri Lelli <juri.lelli@arm.com> >Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> >--- >v1 -> v2: > * move sched_dl_global_constraints before sched_rt_global_constraints, > and change the name of the former to sched_dl_global_validate(). > > kernel/sched/core.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > >diff --git a/kernel/sched/core.c b/kernel/sched/core.c >index 603c462..981f075 100644 >--- a/kernel/sched/core.c >+++ b/kernel/sched/core.c >@@ -7808,7 +7808,7 @@ static int sched_rt_global_constraints(void) > } > #endif /* CONFIG_RT_GROUP_SCHED */ > >-static int sched_dl_global_constraints(void) >+static int sched_dl_global_validate(void) > { > u64 runtime = global_rt_runtime(); > u64 period = global_rt_period(); >@@ -7909,11 +7909,11 @@ int sched_rt_handler(struct ctl_table *table, int write, > if (ret) > goto undo; > >- ret = sched_rt_global_constraints(); >+ ret = sched_dl_global_validate(); > if (ret) > goto undo; > >- ret = sched_dl_global_constraints(); >+ ret = sched_rt_global_constraints(); > if (ret) > goto undo; > >-- >1.9.1
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