The following commit has been merged into the sched/core branch of tip: Commit-ID: ca528cc501896a808dc79c3c0544369d23b331c8 Gitweb: https://git.kernel.org/tip/ca528cc501896a808dc79c3c0544369d23b331c8 Author: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> AuthorDate: Thu, 06 Apr 2023 13:31:45 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Mon, 08 May 2023 10:58:37 +02:00 sched/topology: Remove SHARED_CHILD from ASYM_PACKING Only x86 and Power7 use ASYM_PACKING. They use it differently. Power7 has cores of equal priority, but the SMT siblings of a core have different priorities. Parent scheduling domains do not need (nor have) the ASYM_PACKING flag. SHARED_CHILD is not needed. Using SHARED_PARENT would cause the topology debug code to complain. X86 has cores of different priority, but all the SMT siblings of the core have equal priority. It needs ASYM_PACKING at the MC level, but not at the SMT level (it also needs it at upper levels if they have scheduling groups of different priority). Removing ASYM_PACKING from the SMT domain causes the topology debug code to complain. Remove SHARED_CHILD for now. We still need a topology check that satisfies both architectures. Suggested-by: Valentin Schneider <vschneid@xxxxxxxxxx> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Tested-by: Zhang Rui <rui.zhang@xxxxxxxxx> Link: https://lore.kernel.org/r/20230406203148.19182-10-ricardo.neri-calderon@xxxxxxxxxxxxxxx --- include/linux/sched/sd_flags.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/include/linux/sched/sd_flags.h b/include/linux/sched/sd_flags.h index 57bde66..fad77b5 100644 --- a/include/linux/sched/sd_flags.h +++ b/include/linux/sched/sd_flags.h @@ -132,12 +132,9 @@ SD_FLAG(SD_SERIALIZE, SDF_SHARED_PARENT | SDF_NEEDS_GROUPS) /* * Place busy tasks earlier in the domain * - * SHARED_CHILD: Usually set on the SMT level. Technically could be set further - * up, but currently assumed to be set from the base domain - * upwards (see update_top_cache_domain()). * NEEDS_GROUPS: Load balancing flag. */ -SD_FLAG(SD_ASYM_PACKING, SDF_SHARED_CHILD | SDF_NEEDS_GROUPS) +SD_FLAG(SD_ASYM_PACKING, SDF_NEEDS_GROUPS) /* * Prefer to place tasks in a sibling domain
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