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x86, perf, bts, mm: Delete the never used BTS-ptrace code

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Support for the PMU's BTS features has been upstreamed in
v2.6.32, but we still have the old and disabled ptrace-BTS,
as Linus noticed it not so long ago.

It's buggy: TIF_DEBUGCTLMSR is trampling all over that MSR without
regard for other uses (perf) and doesn't provide the flexibility
needed for perf either.

Its users are ptrace-block-step and ptrace-bts, since ptrace-bts
was never used and ptrace-block-step can be implemented using a
much simpler approach.

So axe all 3000 lines of it. That includes the *locked_memory*()
APIs in mm/mlock.c as well.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100325135413.938004390@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2010-03-25 14:51:50 +01:00
committed by Ingo Molnar
parent 7c5ecaf766
commit faa4602e47
34 changed files with 9 additions and 3269 deletions
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43
kernel/sched.c
View File

@@ -2076,49 +2076,6 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
return 1;
}
/*
* wait_task_context_switch - wait for a thread to complete at least one
* context switch.
*
* @p must not be current.
*/
void wait_task_context_switch(struct task_struct *p)
{
unsigned long nvcsw, nivcsw, flags;
int running;
struct rq *rq;
nvcsw = p->nvcsw;
nivcsw = p->nivcsw;
for (;;) {
/*
* The runqueue is assigned before the actual context
* switch. We need to take the runqueue lock.
*
* We could check initially without the lock but it is
* very likely that we need to take the lock in every
* iteration.
*/
rq = task_rq_lock(p, &flags);
running = task_running(rq, p);
task_rq_unlock(rq, &flags);
if (likely(!running))
break;
/*
* The switch count is incremented before the actual
* context switch. We thus wait for two switches to be
* sure at least one completed.
*/
if ((p->nvcsw - nvcsw) > 1)
break;
if ((p->nivcsw - nivcsw) > 1)
break;
cpu_relax();
}
}
/*
* wait_task_inactive - wait for a thread to unschedule.
*