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[PATCH 5/5][djprobe] delayed invoking commit_djprobes()
- From: Masami Hiramatsu <masami dot hiramatsu dot pt at hitachi dot com>
- To: "Keshavamurthy, Anil S" <anil dot s dot keshavamurthy at intel dot com>, Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, Prasanna S Panchamukhi <prasanna at in dot ibm dot com>, Ingo Molnar <mingo at redhat dot com>, SystemTAP <systemtap at sources dot redhat dot com>
- Cc: Masami Hiramatsu <masami dot hiramatsu dot pt at hitachi dot com>, Satoshi Oshima <soshima at redhat dot com>, Hideo Aoki <haoki at redhat dot com>, Yumiko Sugita <yumiko dot sugita dot yf at hitachi dot com>
- Date: Thu, 19 Oct 2006 18:03:26 +0900
- Subject: [PATCH 5/5][djprobe] delayed invoking commit_djprobes()
- Organization: Systems Development Lab., Hitachi, Ltd., Japan
- References: <45338593.6090207@hitachi.com>
Hi,
This patch invokes commit_djprobes() function from a worker.
This worker is scheduled automatically by register/
unregister_djprobe() functions and is executed in 0.1 second.
If the worker fails freezing processes, it will try again
after 0.1 second.
Thanks,
--
Masami HIRAMATSU
Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
---
kernel/djprobe.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
Index: linux-2.6.19-rc1-mm1/kernel/djprobe.c
===================================================================
--- linux-2.6.19-rc1-mm1.orig/kernel/djprobe.c 2006-10-16 22:06:22.000000000 +0900
+++ linux-2.6.19-rc1-mm1/kernel/djprobe.c 2006-10-16 22:06:44.000000000 +0900
@@ -64,6 +64,15 @@
static LIST_HEAD(registering_list);
static LIST_HEAD(unregistering_list);
+static void commit_work_fn(void * data);
+static DECLARE_WORK(commit_work, commit_work_fn, 0);
+#define DJPROBE_COMMIT_DELAY (HZ/10)
+
+static __always_inline void kick_delayed_commit(void)
+{
+ schedule_delayed_work(&commit_work, DJPROBE_COMMIT_DELAY);
+}
+
static int __djprobe_pre_handler(struct kprobe *kp, struct pt_regs *regs)
{
struct djprobe_instance *djpi =
@@ -211,12 +220,18 @@
int __kprobes commit_djprobes(void)
{
- int ret;
+ int ret = 0;
BUG_ON(in_interrupt());
+ commit_work_fn(NULL);
+ return ret;
+}
+
+static void commit_work_fn(void * data)
+{
mutex_lock(&djprobe_mutex);
- ret = __commit_djprobes();
+ if (__commit_djprobes() < 0)
+ kick_delayed_commit();/* try again */
mutex_unlock(&djprobe_mutex);
- return ret;
}
int __kprobes register_djprobe(struct djprobe *djp)
@@ -265,6 +280,7 @@
djp->inst = djpi;
INIT_LIST_HEAD(&djp->plist);
list_add_rcu(&djp->plist, &djpi->plist);
+ kick_delayed_commit();
out:
mutex_unlock(&djprobe_mutex);
@@ -286,6 +302,7 @@
list_del_init(&djpi->rlist);
arch_pre_remove_djprobe_instance(djpi);
list_add(&djpi->rlist, &unregistering_list);
+ kick_delayed_commit();
}
mutex_unlock(&djprobe_mutex);
}