Hi,
I've tested the libfdt update on STM32MP1. I can see a boot time increase by ~6%, thanks to U-Boot 'bootstage report' command. But I don't think this should block the lib upgrade. I've some comments about the patch, I'll send that on gerrit.
Regards, Yann
On 6/17/20 1:03 AM, Madhukar Pappireddy via TF-A wrote:
Hi Varun,
I have pushed the draft patch here [1] to upgrade the libfdt source files. I have tested this patch by running all tests that we usually run before merging a patch to TF-A repo. I am looking forward to receiving feedback from platform owners.
However, I am not convinced why this effort needs an exhaustive evaluation with various criteria as you mentioned below. I am upgrading source files and I am not introducing a new project to TF-A. Let me know your thoughts.
[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4596
Thanks,
Madhukar
*From:* Varun Wadekar vwadekar@nvidia.com *Sent:* Monday, June 15, 2020 2:12 PM *To:* Madhukar Pappireddy Madhukar.Pappireddy@arm.com *Cc:* tf-a@lists.trustedfirmware.org *Subject:* RE: Upgrading libfdt library
Thanks, Madhukar.
I think this needs a broader discussion where we form a list evaluation criteria of features, API, metrics, KPIs etc by pooling them from the platform owners.
If we don’t receive any inputs, then it makes sense to execute the current tests and make sure that they work as expected.
Thoughts?
-Varun
*From:* Madhukar Pappireddy <Madhukar.Pappireddy@arm.com mailto:Madhukar.Pappireddy@arm.com> *Sent:* Monday, June 15, 2020 8:30 AM *To:* Varun Wadekar <vwadekar@nvidia.com mailto:vwadekar@nvidia.com> *Cc:* tf-a@lists.trustedfirmware.org mailto:tf-a@lists.trustedfirmware.org *Subject:* RE: Upgrading libfdt library
*External email: Use caution opening links or attachments*
Hi Varun,
Please find my replies inline.
Thanks,
Madhu
*From:* Varun Wadekar <vwadekar@nvidia.com mailto:vwadekar@nvidia.com> *Sent:* Friday, June 12, 2020 7:04 PM *To:* Madhukar Pappireddy <Madhukar.Pappireddy@arm.com mailto:Madhukar.Pappireddy@arm.com> *Cc:* tf-a@lists.trustedfirmware.org mailto:tf-a@lists.trustedfirmware.org *Subject:* RE: Upgrading libfdt library
Hi Madhukar,
Before we merge this change, can you please explain how we arrived at this specific version? Are we tracking the stable version of the library?
I was told by Andre that the releases(tags) by themselves don’t mean
much in the libfdt project and it is better to upgrade directly to the recent commit(the latest HEAD was 85e5d83 when I started this investigation).
What would be the testing criteria before merging the library? Does tftf provide any tests that can act as a smoking gun?
Given that we rely more on libfdt APIs now, I plan to run all the
existing tests in our CI (includes tftf and Linux boot tests) to verify if the libfdt library has any issues when integrating with TF-A. I believe these tests are thorough enough.
Does it make sense to ask platform owners to test the specific version you plan to merge? This way we would have more confidence in the library.
Yes, I wanted to take the feedback from platform owners and hence I
sent this email before actually pushing the patch to tf.org for review. There was a performance concern in the past when upgrading libfdt source files [1].
[1] https://github.com/ARM-software/tf-issues/issues/643
-Varun
*From:* TF-A <tf-a-bounces@lists.trustedfirmware.org mailto:tf-a-bounces@lists.trustedfirmware.org> *On Behalf Of *Madhukar Pappireddy via TF-A *Sent:* Friday, June 12, 2020 4:48 PM *To:* tf-a@lists.trustedfirmware.org mailto:tf-a@lists.trustedfirmware.org *Subject:* [TF-A] Upgrading libfdt library
*External email: Use caution opening links or attachments*
Hello,
I am planning to upgrade libfdt library source files in TF-A. They haven’t been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A.
Please let me know if you are aware of any performance issues or have other concerns.
[1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
Thanks,
Madhu