sched: /proc/sched_debug fails on very very large machines

sched: /proc/sched_debug fails on very very large machines

On systems with 4096 cores attemping to read /proc/sched_debug fails.  We
are trying to push all the data into a single kmalloc buffer.  The issue
is on these very large machines all the data will not fit in 4mb.

A better solution is to not us the single_open mechanism but to provide
our own seq_operations and treat each cpu as an individual record.

The output should be identical to previous version.

Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Reported-by: Dave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>)
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>