[Prev] Thread [Next]  |  [Prev] Date [Next]

Re: [Adeos-main] [pull request] Improve ftrace interaction Jan Kiszka Sun Mar 14 03:00:05 2010

Philippe Gerum wrote:
> On Tue, 2010-03-09 at 19:04 +0100, Jan Kiszka wrote:
>> The following changes since commit 7c90959b7e4eb5ef8a775ec17005c23f30daade1:
>>   Philippe Gerum (1):
>>         ipipe: introduce 3-level IRQ pending map
>> are available in the git repository at:
>>   git://git.kiszka.org/ipipe-2.6 queues/2.6.32-noarch
>> These patches address various possible configuration errors around
>> ftrace that can cause hard crashes over I-pipe kernels. Moreover, one
>> patch enables the safe use of ftrace's PID filtering that comes for free
>> for the I-pipe tracer now.
>> The patches also apply on 2.6.33-noarch but were only tested on
>> 2.6.32-x86.
>> Jan Kiszka (5):
>>       Use ipipe_safe_current in ftrace_pid_func
>>       Prevent unsafe ftrace usage over I-pipe
> This one looks pretty ugly. I would rather define a entry point for
> registering ftrace hooks allowed to run in NMI context, and deny the
> regular unsafe registration routine when the I-pipe tracer is enabled.

I just learned yesterday from Frederic that the ftrace ring buffer
should be NMI-safe by now. I need to look into this again, maybe we can
make _much_ more of ftrace usable for I-pipe. IOW: Series on hold.


Adeos-main mailing list