Revert "sched: Fix SD_OVERLAP"

This reverts commit c39e81ea0c684f209241b00f8cbcf15736e560d6.
Revert "sched/fair: Add some serialization to the sched_domain load-balance walk"

This reverts commit 6356e8253f1a32f8dac3aedc49ae90a0f889340e.
Revert "Revert "sched: pack the idle load balance""

This reverts commit 35d8d9507dd573e7b926f9726f3222eccadd627a.
Revert "sched: remove one division operation in find_buiest_queue()"

This reverts commit 748743aa8782276e4a7f100578d8352770804b68.
Revert "sched: pack the idle load balance"

This reverts commit 7e34382ccc94e1897dcc6c3ded51d14714827f05.
Revert "sched: secure access to other CPU statistics"

This reverts commit 370fdc11faccd7ded318ad931784163f5da49458.
Revert "sched: pack small tasks"

This reverts commit 3efa9bfe7c99de5468cbd8edf3a707b69a14efc5.
Revert "fs: add read_iter and write_iter to several file systems"

This reverts commit 6daeedc8c8f436c27b12add74330fb00c211d8ec.