-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 06/30/2014 12:05 PM, Vincent Guittot wrote: > I have tried to understand the meaning of the condition : > (this_load <= load && this_load + target_load(prev_cpu, idx) <= > tl_per_task) but i failed to find a use case that can take > advantage of it and i haven't found clear description in the > previous commits' log. Futhermore, the comment of the condition > refers to the task_hot function that was used before being replaced > by the current condition: /* * This domain has SD_WAKE_AFFINE and * > p is cache cold in this domain, and * there is no bad imbalance. > */ > > If we look more deeply the below condition this_load + > target_load(prev_cpu, idx) <= tl_per_task > > When sync is clear, we have : tl_per_task = runnable_load_avg / > nr_running this_load = max(runnable_load_avg, cpuload[idx]) > target_load = max(runnable_load_avg', cpuload'[idx]) > > It implies that runnable_load_avg' == 0 and nr_running <= 1 in > order to match the condition. This implies that runnable_load_avg > == 0 too because of the condition: this_load <= load but if this > _load is null, balanced is already set and the test is redundant. > > If sync is set, it's not as straight forward as above (especially > if cgroup are involved) but the policy should be similar as we have > removed a task that's going to sleep in order to get a more > accurate load and this_load values. > > The current conclusion is that these additional condition don't > give any benefit so we can remove them. > > Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
Acked-by: Rik van Riel <r...@redhat.com> - -- All rights reversed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTvLG+AAoJEM553pKExN6DfhMH/iYJAS/nCq1teCNm39zZg1bF MIp2iWwnB5VTQvwVLQ3FaGU80oWScUez8zjn26LjPp5SnxyDEwG0YVM3/57EyJme PgffmP8xsVJwRkKnO4VRR0Go2EMXl9cdf9exe6lFjRyv4/Z15o9NZsDmX8JcLmG+ JPKq4DnMpJ3LiMiVuwwYtYSLk/tCHCPLnie4Z/WznlHk220WciVXFZG7AQI2AHXj pMkZ5TWQODW7PEec+8dGzDnFcdXPftRYWCKLXG+9NM92YQpIsK8nZdC8rJeXhjBC 9VNb8QNZ6yVd0lvOSxy0drOV9BFXUImF6lsLxA12oHE6TLm6FeiHTG9X4xGOhN0= =XlY9 -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
