Messages in this thread | | | Date | Fri, 24 Mar 2017 07:35:02 +0900 | From | Byungchul Park <> | Subject | Re: [PATCH 0/8] sched/deadline: Return the best satisfying affinity and dl in cpudl_find |
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On Thu, Mar 23, 2017 at 07:32:35PM +0900, Byungchul Park wrote: > cpudl_find() is used to find a cpu having the latest dl. The function > should return the latest cpu among ones satisfying task's affinity and > dl constraint, but current code gives up immediately and just return > fail when it fails at the test *only with* the maximum cpu. > > For example: > > cpu 0 is running a task (dl: 10). > cpu 1 is running a task (dl: 9). > cpu 2 is running a task (dl: 8). > cpu 3 is running a task (dl: 2). ^ should be 1 > > where cpu 3 want to push a task (affinity is 1 2 3 and dl is 1). ^ should be 2 > > In this case, the task should be migrated from cpu 3 to cpu 1, and > preempt cpu 1's task. However, current code just returns fail because > it fails at the affinity test with the maximum cpu, that is, cpu 0. > > This patch set tries to find the best among ones satisfying task's > affinity and dl constraint until success or no more to see. > > Byungchul Park (8): > sched/deadline: Make find_later_rq() choose a closer cpu in topology > sched/deadline: Re-define parameters of cpudl heapify functions > sched/deadline: Add cpudl_maximum_dl() for clean-up > sched/deadline: Factor out the selecting of suitable max cpu > sched/deadline: Protect read of cpudl heap with a lock > sched/deadline: Don't return meaningless cpu in cpudl_maximum_cpu() > sched/deadline: Factor out the modifying of cpudl's heap tree > sched/deadline: Return the best satisfying affinity and dl in > cpudl_find > > kernel/sched/cpudeadline.c | 228 +++++++++++++++++++++++++++++++-------------- > kernel/sched/cpudeadline.h | 9 ++ > kernel/sched/deadline.c | 29 +++--- > 3 files changed, 182 insertions(+), 84 deletions(-) > > -- > 1.9.1
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