Re: utrace support on ARM
utrace per se has no machine-dependent code. It requires modern support for machine dependencies in generic kernel code, i.e. user_regset and tracehook. The ARM kernel has a tiny subset of those, but not enough to be useful. Long ago I did 98% of the work for implementing user_regset and tracehook support for ARM and posted it This is the patch set Roland refers to if someone wants to help push arm forward: http://lkml.org/lkml/2009/4/24/383 Cheers, Mark
RE: utrace support on ARM
Thanks I will see if I can interest people in TI and Linaro. I will need a good story... ;-) Regards Fred Frederic Turgis OMAP Platform Business Unit - OMAP System Engineering - Platform Enablement Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve Loubet. 036 420 040 R.C.S Antibes. Capital de EUR 753.920 -Original Message- From: Mark Wielaard [mailto:m...@redhat.com] Sent: Friday, April 22, 2011 10:18 AM To: Roland McGrath Cc: Frank Ch. Eigler; utrace-devel@redhat.com; Turgis, Frederic Subject: Re: utrace support on ARM utrace per se has no machine-dependent code. It requires modern support for machine dependencies in generic kernel code, i.e. user_regset and tracehook. The ARM kernel has a tiny subset of those, but not enough to be useful. Long ago I did 98% of the work for implementing user_regset and tracehook support for ARM and posted it This is the patch set Roland refers to if someone wants to help push arm forward: http://lkml.org/lkml/2009/4/24/383 Cheers, Mark
RE: utrace support on ARM
I will see if I can interest people in TI and Linaro. I will need a good story... ;-) It is kernel port modernization work that nearly every other platform has done by now.
RE: utrace support on ARM
Hi Turgis, On Wed, 2011-04-20 at 10:00 +0200, Turgis, Frederic wrote: * utrace has not been accepted upstream. Does it mean it may lose traction ? Is community pushing for something else or happy with what they have ? Parts haven't. utrace builds upon regsets and tracehooks, which are both in the mainline kernel already. But the answer is both. Lots of distros ship kernels with utrace enabled already. But there is also... * I have also found IBM presentation on utrace-less uprobes. How does it affect utrace ? It doesn't affect it directly. It is just another way to have user space probes working (but without the easy task triggers). So projects that now use a combination of utrace and uprobes will have to adjust a little to work without the easy taks level triggers that utrace brings and use the page level triggers that the new uprobes proposal has. Cheers, Mark
Re: utrace support on ARM
f-turgis wrote: [...] So I am interested in this kind of status: * utrace has not been accepted upstream. Does it mean it may lose traction ? Is community pushing for something else or happy with what they have ? [...] There are many communities. I am not anticipating additional utrace uptake at this time. * I have also found IBM presentation on utrace-less uprobes. How does it affect utrace ? It doesn't. As far as systemtap's concerned, if the new uprobes turn out to be versatile enough, we will use them. As far as a systemtap user's concerned, it's all an implementation detail. The scripts should be exactly the same. - FChE
Re: utrace support on ARM
On Tue, 2011-03-29 at 16:26 +0200, Turgis, Frederic wrote: - http://people.redhat.com/roland/utrace is no longer valid. Where has it been moved ? http://userweb.kernel.org/~frob/utrace/ - Mail archive in https://www.redhat.com/archives/utrace-devel/ stops in December. Did I miss something ? No, that is right. It should now have two new emails in March :) Cheers, Mark
