[PATCH 6/9] Task Watchers v2: Register IRQ flag tracing task watcher

Matt Helsley
2006-11-03T04:23:03Z

[-- Attachment #1: task-watchers-register-trace-irqflags --]
[-- Type: text/plain, Size: 4659 bytes --]

Register an irq-flag-tracing task watcher instead of hooking into
copy_process().

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
---
kernel/fork.c | 19 -------------------
kernel/irq/handle.c | 24 ++++++++++++++++++++++++
2 files changed, 24 insertions(+), 19 deletions(-)

Benchmark results:
System: 4 1.7GHz ppc64 (Power 4+) processors, 30968600MB RAM, 2.6.19-rc2-mm2 kernel

Clone Number of Children Cloned
5000 7500 10000 12500 15000 17500
---------------------------------------------------------------------------------------
Mean 17826.5 18077.4 18160.1 18263.6 18343 18350.8
Dev 305.841 306.331 283.323 284.761 292.732 292.882
Err (%) 1.71565 1.69455 1.56014 1.55917 1.59588 1.59602

Fork Number of Children Forked
5000 7500 10000 12500 15000 17500
---------------------------------------------------------------------------------------
Mean 17813.5 18062.4 18140.5 18246.7 18237.8 18275.2
Dev 305.816 294.914 294.779 294.727 323.996 300.176
Err (%) 1.71677 1.63275 1.62498 1.61523 1.77651 1.64253

Kernbench:
Elapsed: 124.4s User: 439.787s System: 46.485s CPU: 390.3%
439.70user 46.43system 2:04.64elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.92user 46.38system 2:04.47elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.79user 46.62system 2:04.44elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.83user 46.46system 2:04.29elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.73user 46.47system 2:04.12elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.83user 46.49system 2:04.10elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.76user 46.42system 2:04.41elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k
439.70user 46.64system 2:04.30elapsed 391%CPU (0avgtext+0avgdata 0maxresident)k
439.79user 46.47system 2:04.76elapsed 389%CPU (0avgtext+0avgdata 0maxresident)k
439.82user 46.47system 2:04.47elapsed 390%CPU (0avgtext+0avgdata 0maxresident)k

Index: linux-2.6.19-rc2-mm2/kernel/fork.c
===================================================================
--- linux-2.6.19-rc2-mm2.orig/kernel/fork.c
+++ linux-2.6.19-rc2-mm2/kernel/fork.c
@@ -1052,29 +1052,10 @@ static struct task_struct *copy_process(
p->tgid = current->tgid;

retval = notify_task_watchers(WATCH_TASK_INIT, clone_flags, p);
if (retval < 0)
goto bad_fork_cleanup_delays_binfmt;
-#ifdef CONFIG_TRACE_IRQFLAGS
- p->irq_events = 0;
-#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
- p->hardirqs_enabled = 1;
-#else
- p->hardirqs_enabled = 0;
-#endif
- p->hardirq_enable_ip = 0;
- p->hardirq_enable_event = 0;
- p->hardirq_disable_ip = _THIS_IP_;
- p->hardirq_disable_event = 0;
- p->softirqs_enabled = 1;
- p->softirq_enable_ip = _THIS_IP_;
- p->softirq_enable_event = 0;
- p->softirq_disable_ip = 0;
- p->softirq_disable_event = 0;
- p->hardirq_context = 0;
- p->softirq_context = 0;
-#endif
#ifdef CONFIG_LOCKDEP
p->lockdep_depth = 0; /* no locks held yet */
p->curr_chain_key = 0;
p->lockdep_recursion = 0;
#endif
Index: linux-2.6.19-rc2-mm2/kernel/irq/handle.c
===================================================================
--- linux-2.6.19-rc2-mm2.orig/kernel/irq/handle.c
+++ linux-2.6.19-rc2-mm2/kernel/irq/handle.c
@@ -13,10 +13,11 @@
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
+#include <linux/task_watchers.h>

#include "internals.h"

/**
* handle_bad_irq - handle spurious and unhandled irqs
@@ -266,6 +267,29 @@ void early_init_irq_lock_class(void)

for (i = 0; i < NR_IRQS; i++)
lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
}

+static int init_task_trace_irqflags(unsigned long clone_flags,
+ struct task_struct *p)
+{
+ p->irq_events = 0;
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+ p->hardirqs_enabled = 1;
+#else
+ p->hardirqs_enabled = 0;
+#endif
+ p->hardirq_enable_ip = 0;
+ p->hardirq_enable_event = 0;
+ p->hardirq_disable_ip = _THIS_IP_;
+ p->hardirq_disable_event = 0;
+ p->softirqs_enabled = 1;
+ p->softirq_enable_ip = _THIS_IP_;
+ p->softirq_enable_event = 0;
+ p->softirq_disable_ip = 0;
+ p->softirq_disable_event = 0;
+ p->hardirq_context = 0;
+ p->softirq_context = 0;
+ return 0;
+}
+task_watcher_func(init, init_task_trace_irqflags);
#endif