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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-11 04:53:40 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-11 04:53:40 +0200
commit862366118026a358882eefc70238dbcc3db37aac (patch)
tree4eb62bc10327a5afac064a95a091ea05ecd2acc1 /kernel/sched.c
parentMerge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
parentRevert "x86, bts: reenable ptrace branch trace support" (diff)
downloadlinux-862366118026a358882eefc70238dbcc3db37aac.tar.xz
linux-862366118026a358882eefc70238dbcc3db37aac.zip
Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c55
1 files changed, 47 insertions, 8 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 076e403b9c88..14c447ae5d53 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -72,13 +72,15 @@
#include <linux/debugfs.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
-#include <trace/sched.h>
#include <asm/tlb.h>
#include <asm/irq_regs.h>
#include "sched_cpupri.h"
+#define CREATE_TRACE_POINTS
+#include <trace/events/sched.h>
+
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
@@ -118,12 +120,6 @@
*/
#define RUNTIME_INF ((u64)~0ULL)
-DEFINE_TRACE(sched_wait_task);
-DEFINE_TRACE(sched_wakeup);
-DEFINE_TRACE(sched_wakeup_new);
-DEFINE_TRACE(sched_switch);
-DEFINE_TRACE(sched_migrate_task);
-
#ifdef CONFIG_SMP
static void double_rq_lock(struct rq *rq1, struct rq *rq2);
@@ -1964,7 +1960,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
clock_offset = old_rq->clock - new_rq->clock;
- trace_sched_migrate_task(p, task_cpu(p), new_cpu);
+ trace_sched_migrate_task(p, new_cpu);
#ifdef CONFIG_SCHEDSTATS
if (p->se.wait_start)
@@ -2021,6 +2017,49 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
}
/*
+ * 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.
*
* If @match_state is nonzero, it's the @p->state value just checked and