Devicetree state of U-Boot vs kernel
All,
On the Devicetree evolution call Wednesday I promised to finish my comparison of u-boot DT vs kernel DT. The script is not perfect but the results are still interesting.
For each dts and dtsi file in the tip of the u-boot tree, it tries to correlate it to the kernel tip. It compares git SHA1 signatures or falls back to filenames. The results were surprising to me but perhaps they should not have been.
I have checked in the script[1] and the full results here [2]
The full file lists (with some diff stats) are in the root dir. Example [3]
I also looked at the line count of the u-boot override files. Even though we don't expect these to correlate, we do expect reasonable usage to result in small files. Big files are an indication of possible abuse of the system. (I don't think the idea was to have wholesale new versions of the DTS as an override.)
I plan to redo the script in python. It will be much easier to be more precise and to look deeper. (For example figure out how old the u-boot version is in number of change sets and number of days. Or if no content sync now were they ever synced?)
Here is the scripts output: (from summary.txt)
Devicetree sync status for u-boot v2021.01-rc5-7-gb8c725e736 Compared to kernel v5.11-rc2-156-g71c061d24438 14% (255) are completely synced 253 arm 2 riscv 0 mips 0 powerpc 0 x86 0 68k 0 microblaze 0 sh 0 arc 23% (416) content has appeared in the kernel but is not up to date 411 arm 0 riscv 1 mips 0 powerpc 1 x86 0 68k 0 microblaze 0 sh 1 arc 33% (584) filename appears in kernel but content never has 467 arm 1 riscv 12 mips 91 powerpc 0 x86 0 68k 0 microblaze 0 sh 8 arc 28% (510) neither filename nor content appears in kernel 305 arm 4 riscv 48 mips 35 powerpc 44 x86 0 68k 1 microblaze 1 sh 6 arc n/a (510) U-Boot specific, no correlation expected 7 sandbox 358 override 211 test histogram of override size (in raw lines) 10 61 20 53 30 38 40 33 50 23 60 14 70 12 80 7 90 5 100 4 110 4 120 5 130 6 140 4 150 0 160 2 170 0 180 0 190 4 200 0 210 2 220 2 230 1 240 2 250 1 260 1 270 1 280 0 290 0 300 0 310 0 320 1
[1] https://github.com/wmamills/devicetree-source/blob/master/scripts/correlate-... [2] https://github.com/wmamills/devicetree-source [3] https://github.com/wmamills/devicetree-source/blob/master/dts-somewhere.txt
Hi,
On 08/01/2021 01:39, Bill Mills wrote:
All,
On the Devicetree evolution call Wednesday I promised to finish my comparison of u-boot DT vs kernel DT. The script is not perfect but the results are still interesting.
For each dts and dtsi file in the tip of the u-boot tree, it tries to correlate it to the kernel tip. It compares git SHA1 signatures or falls back to filenames. The results were surprising to me but perhaps they should not have been.
I have checked in the script[1] and the full results here [2]
The full file lists (with some diff stats) are in the root dir. Example [3]
I also looked at the line count of the u-boot override files. Even though we don't expect these to correlate, we do expect reasonable usage to result in small files. Big files are an indication of possible abuse of the system. (I don't think the idea was to have wholesale new versions of the DTS as an override.)
I plan to redo the script in python. It will be much easier to be more precise and to look deeper. (For example figure out how old the u-boot version is in number of change sets and number of days. Or if no content sync now were they ever synced?)
Here is the scripts output: (from summary.txt)
Devicetree sync status for u-boot v2021.01-rc5-7-gb8c725e736 Compared to kernel v5.11-rc2-156-g71c061d24438
Do not compare with a such kernel, usually DT is sync'ed from stable kernels, or -rc1, so 5.11 stuff will eventually go for next u-boot release, not the actual one.
We (amlogic/meson) will sync part of DT with 5.10 for next release, the previous is sync'ed to 5.9/5.8.
It's almost impossible to sync to each release.
Neil
14% (255) are completely synced 253 arm 2 riscv 0 mips 0 powerpc 0 x86 0 68k 0 microblaze 0 sh 0 arc 23% (416) content has appeared in the kernel but is not up to date 411 arm 0 riscv 1 mips 0 powerpc 1 x86 0 68k 0 microblaze 0 sh 1 arc 33% (584) filename appears in kernel but content never has 467 arm 1 riscv 12 mips 91 powerpc 0 x86 0 68k 0 microblaze 0 sh 8 arc 28% (510) neither filename nor content appears in kernel 305 arm 4 riscv 48 mips 35 powerpc 44 x86 0 68k 1 microblaze 1 sh 6 arc n/a (510) U-Boot specific, no correlation expected 7 sandbox 358 override 211 test histogram of override size (in raw lines) 10 61 20 53 30 38 40 33 50 23 60 14 70 12 80 7 90 5 100 4 110 4 120 5 130 6 140 4 150 0 160 2 170 0 180 0 190 4 200 0 210 2 220 2 230 1 240 2 250 1 260 1 270 1 280 0 290 0 300 0 310 0 320 1
[1] https://github.com/wmamills/devicetree-source/blob/master/scripts/correlate-... [2] https://github.com/wmamills/devicetree-source [3] https://github.com/wmamills/devicetree-source/blob/master/dts-somewhere.txt
On Wed, Jan 13, 2021 at 02:30:03PM +0100, Neil Armstrong wrote:
Hi,
On 08/01/2021 01:39, Bill Mills wrote:
All,
On the Devicetree evolution call Wednesday I promised to finish my comparison of u-boot DT vs kernel DT. The script is not perfect but the results are still interesting.
For each dts and dtsi file in the tip of the u-boot tree, it tries to correlate it to the kernel tip. It compares git SHA1 signatures or falls back to filenames. The results were surprising to me but perhaps they should not have been.
I have checked in the script[1] and the full results here [2]
The full file lists (with some diff stats) are in the root dir. Example [3]
I also looked at the line count of the u-boot override files. Even though we don't expect these to correlate, we do expect reasonable usage to result in small files. Big files are an indication of possible abuse of the system. (I don't think the idea was to have wholesale new versions of the DTS as an override.)
I plan to redo the script in python. It will be much easier to be more precise and to look deeper. (For example figure out how old the u-boot version is in number of change sets and number of days. Or if no content sync now were they ever synced?)
Here is the scripts output: (from summary.txt)
Devicetree sync status for u-boot v2021.01-rc5-7-gb8c725e736 Compared to kernel v5.11-rc2-156-g71c061d24438
Do not compare with a such kernel, usually DT is sync'ed from stable kernels, or -rc1, so 5.11 stuff will eventually go for next u-boot release, not the actual one.
We (amlogic/meson) will sync part of DT with 5.10 for next release, the previous is sync'ed to 5.9/5.8.
It's almost impossible to sync to each release.
It's also something left up to the custodians, but it's also expected to sync things when our -rc1 window is open with the latest best-choice upstream Linux kernel. There is of course, work to be done still and tooling to better / more easily identify the gaps is good.
participants (3)
-
Bill Mills -
Neil Armstrong -
Tom Rini