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[RFC] [PATCH] tapsets to provide memory related information
- From: Srinivasa Ds <srinivasa at in dot ibm dot com>
- To: SystemTAP <systemtap at sources dot redhat dot com>
- Date: Wed, 19 Sep 2007 19:25:27 +0530
- Subject: [RFC] [PATCH] tapsets to provide memory related information
Hi
I have developed some memory related tapsets. These tapsets
display tasks maximum virtual size, current virtual size,
hiwater_rss,hiwater_vm,anon_rss.
I have encountered some challenges here. Could someone please
comment on these.
1) I have not incremented mm_users count while reading
data from struct_mm. This is because we may sleep while decrementing
it(mmput() sleeps). Does rcu_read_lock() helps here?
2) I have to use atomic_long_read() to read atomic variables
like _anon_rss,_file_rss. Is there any kread() equivalent to read atomic
variables.
Iam attaching the patch here. Iam planning to format the data cleanly. Please
let me know your comments.
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
---
tapset/task.stp | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
Index: src/tapset/task.stp
===================================================================
--- src.orig/tapset/task.stp
+++ src/tapset/task.stp
@@ -189,3 +189,54 @@ function task_max_file_handles:long (tas
CATCH_DEREF_FAULT();
%}
%)
+
+function task_vsize:long (task:long) %{
+ struct task_struct *t = (struct task_struct *)(long)THIS->task;
+ struct mm_struct * mm = kread(&(t->mm));
+ if (mm)
+ THIS->__retvalue = kread(&(mm->total_vm));
+ else
+ THIS->__retvalue = 0;
+ CATCH_DEREF_FAULT();
+%}
+
+function task_size:long (task:long) %{
+ struct task_struct *t = (struct task_struct *)(long)THIS->task;
+ struct mm_struct * mm = kread(&(t->mm));
+ if (mm)
+ THIS->__retvalue = kread(&(mm->task_size));
+ else
+ THIS->__retvalue = 0;
+ CATCH_DEREF_FAULT();
+%}
+
+function task_hiwater_rss:long (task:long) %{
+ struct task_struct *t = (struct task_struct *)(long)THIS->task;
+ struct mm_struct * mm = kread(&(t->mm));
+ if (mm)
+ THIS->__retvalue = kread(&(mm->hiwater_rss));
+ else
+ THIS->__retvalue = 0;
+ CATCH_DEREF_FAULT();
+%}
+
+function task_hiwater_vm:long (task:long) %{
+ struct task_struct *t = (struct task_struct *)(long)THIS->task;
+ struct mm_struct * mm = kread(&(t->mm));
+ if (mm)
+ THIS->__retvalue = kread(&(mm->hiwater_vm));
+ else
+ THIS->__retvalue = 0;
+ CATCH_DEREF_FAULT();
+%}
+
+function task_anon_rss:long (task:long) %{
+ struct task_struct *t = (struct task_struct *)(long)THIS->task;
+ struct mm_struct * mm = kread(&(t->mm));
+ if (mm)
+ THIS->__retvalue = atomic_long_read(&(mm->_anon_rss));
+ else
+ THIS->__retvalue = 0;
+ CATCH_DEREF_FAULT();
+%}
+