Is it ok to insert a module multiple times with staprun?

[Shiyao Ma]

If the expr in `if expr' could support function invocation, that would
be awesome.

Currently, only
probe kernel.function("vfs_read") if (some_variable) is supported.


probe kernel.function("vfs_read") if (some_func()) is not supported.


Best.

On Fri, Mar 31, 2017 at 11:40 PM, David Smith <dsmith@redhat.com> wrote:
> On Fri, Mar 31, 2017 at 9:50 AM, David Smith <dsmith@redhat.com> wrote:
>> On Thu, Mar 30, 2017 at 10:51 PM, Shiyao Ma <i@introo.me> wrote:
>
> OK, I had another sneaky thought here. You could use the system()
> function to copy the config file to the /proc file. I haven't had time
> to test this, but in theory something like this should work:
>
> ====
> global config_done
>
> probe procfs.write("config")
> {
>     # process $value here
>    config_done = 1
> }
>
> probe kernel.function("vfs_read") if (config_done)
> {
>    # real processing here...
> }
>
> probe begin
> {
>    system(sprintf("cat config > /proc/systemtap/%s/config", module_name()))
> }
> ====
>
> --
> David Smith
> dsmith@redhat.com
> Red Hat
> http://www.redhat.com
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