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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-03-25 09:51:50 -0400
committerIngo Molnar <mingo@elte.hu>2010-03-26 06:33:55 -0400
commitfaa4602e47690fb11221e00f9b9697c8dc0d4b19 (patch)
treeaf667d1cdff7dc63b6893ee3f27a1f2503229ed1 /kernel/sched.c
parent7c5ecaf7666617889f337296c610815b519abfa9 (diff)
x86, perf, bts, mm: Delete the never used BTS-ptrace code
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>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c43
1 files changed, 0 insertions, 43 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 9ab3cd7858d3..117b7cad31b3 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2077,49 +2077,6 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
2077} 2077}
2078 2078
2079/* 2079/*
2080 * wait_task_context_switch - wait for a thread to complete at least one
2081 * context switch.
2082 *
2083 * @p must not be current.
2084 */
2085void wait_task_context_switch(struct task_struct *p)
2086{
2087 unsigned long nvcsw, nivcsw, flags;
2088 int running;
2089 struct rq *rq;
2090
2091 nvcsw = p->nvcsw;
2092 nivcsw = p->nivcsw;
2093 for (;;) {
2094 /*
2095 * The runqueue is assigned before the actual context
2096 * switch. We need to take the runqueue lock.
2097 *
2098 * We could check initially without the lock but it is
2099 * very likely that we need to take the lock in every
2100 * iteration.
2101 */
2102 rq = task_rq_lock(p, &flags);
2103 running = task_running(rq, p);
2104 task_rq_unlock(rq, &flags);
2105
2106 if (likely(!running))
2107 break;
2108 /*
2109 * The switch count is incremented before the actual
2110 * context switch. We thus wait for two switches to be
2111 * sure at least one completed.
2112 */
2113 if ((p->nvcsw - nvcsw) > 1)
2114 break;
2115 if ((p->nivcsw - nivcsw) > 1)
2116 break;
2117
2118 cpu_relax();
2119 }
2120}
2121
2122/*
2123 * wait_task_inactive - wait for a thread to unschedule. 2080 * wait_task_inactive - wait for a thread to unschedule.
2124 * 2081 *
2125 * If @match_state is nonzero, it's the @p->state value just checked and 2082 * If @match_state is nonzero, it's the @p->state value just checked and