Messages in this thread | | | Date | Mon, 30 Jun 2014 22:26:26 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH 1/4] tracing/uprobes: Revert "Support mix of ftrace and perf" |
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* Oleg Nesterov <oleg@redhat.com> [2014-06-27 19:01:36]:
> This reverts commit 43fe98913c9f67e3b523615ee3316f9520a623e0. > > This patch is very wrong. Firstly, this change leads to unbalanced > uprobe_unregister(). Just for example, > > # perf probe -x /lib/libc.so.6 syscall > # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable > # perf record -e probe_libc:syscall whatever > > after that uprobe is dead (unregistered) but the user of ftrace/perf > can't know this, and it looks as if nobody hits this probe. > > This would be easy to fix, but there are other reasons why it is not > simple to mix ftrace and perf. If nothing else, they can't share the > same ->consumer.filter. This is fixable too, but probably we need to > fix the poorly designed uprobe_register() interface first. At least > "register" and "apply" should be clearly separated. > > Cc: stable@vger.kernel.org # v3.14 > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
-- Thanks and Regards Srikar Dronamraju
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