kernel 5.4.42-v7l+ #1319

[Billybangleballs]

Since the rpi-update installed the 5.4.42 kernel, I have strange entries in my kernel log

System
Pi4B

Raspberry Pi reference 2020-02-13
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 5f884374b6ac6e155330c58caa1fb7249b8badf1, stage4

Jun 1 2020 13:23:40
Copyright (c) 2012 Broadcom
version 6379679d1ec6a8c746d7e77e015f5b56b939976f (clean) (release) (start)

Linux sane4 5.4.42-v7l+ #1319 SMP Wed May 20 14:12:03 BST 2020 armv7l GNU/Linux

Jun  1 20:09:39 sane4 kernel: [12738.744120] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  1 20:09:39 sane4 kernel: [12738.744906] debugfs: Directory '1299' with parent 'clients' already present!
Jun  2 00:32:06 sane4 kernel: [28486.312966] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  2 00:32:06 sane4 kernel: [28486.314136] debugfs: Directory '1299' with parent 'clients' already present!
Jun  2 00:37:02 sane4 kernel: [28781.751161] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  2 00:37:02 sane4 kernel: [28781.751548] debugfs: Directory '1299' with parent 'clients' already present!
Jun  2 00:45:00 sane4 kernel: [29260.416102] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  2 00:45:00 sane4 kernel: [29260.416843] debugfs: Directory '1299' with parent 'clients' already present!
Jun  2 01:12:41 sane4 kernel: [30920.635114] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  2 01:12:41 sane4 kernel: [30920.635450] debugfs: Directory '1299' with parent 'clients' already present!
Jun  2 05:17:42 sane4 kernel: [45622.012919] debugfs: Directory '1299' with parent 'alloc' already present!
Jun  2 05:17:42 sane4 kernel: [45622.013058] debugfs: Directory '1299' with parent 'clients' already present!

The process 1299 belongs to :-
wonko 1299 1.0 4.4 683216 171328 ? Sl Jun01 8:13 /usr/lib/chromium-browser/chromium-browser-v7 --disable-quic --enable-tcp-fast-open --ppapi-flash-path=/usr/lib/chromium-browser/libpepflashplayer.so --ppapi-flash-args=enable_stagevideo_auto=0 --ppapi-flash-version=32.0.0.371 --enable-pinch

Is this something I should be worried about?

[pelwell]

I'm not sure why you seeing those messages, but they appear to be warning that something is trying to create entries in debugfs on behalf of process 1299 (chromium). The vchiq driver creates per-process entries under "clients", and vc-smem does the same under "alloc", so my guess would be that chromium is reinitialising itself in some way. @jc-kynesim might have a better idea of what's going on, but I don't think it's any cause for concern.

[jc-kynesim]

Offhand I have no ideas, but I could well believe that due to sandboxing in Chrome some part of an vcsm or mmal initialization process can't see that a file already exists & tries to recreate it anyway.

[Billybangleballs]

It continued after I posted, eventually tiring of process 1299 and choosing 18792 instead.

Jun 2 06:00:57 sane4 kernel: [48216.757622] debugfs: Directory '1299' with parent 'alloc' already present! Jun 2 06:00:57 sane4 kernel: [48216.757783] debugfs: Directory '1299' with parent 'clients' already present! Jun 2 13:48:03 sane4 kernel: [76243.288079] debugfs: Directory '1299' with parent 'alloc' already present! Jun 2 13:48:03 sane4 kernel: [76243.289216] debugfs: Directory '1299' with parent 'clients' already present! Jun 2 18:47:56 sane4 kernel: [94237.284968] debugfs: Directory '1299' with parent 'alloc' already present! Jun 2 18:47:56 sane4 kernel: [94237.285199] debugfs: Directory '1299' with parent 'clients' already present! Jun 2 20:28:29 sane4 kernel: [100270.074360] debugfs: Directory '1299' with parent 'alloc' already present! Jun 2 20:28:29 sane4 kernel: [100270.074557] debugfs: Directory '1299' with parent 'clients' already present! Jun 3 02:28:02 sane4 kernel: [121843.844461] debugfs: Directory '1299' with parent 'alloc' already present! Jun 3 02:28:02 sane4 kernel: [121843.844603] debugfs: Directory '1299' with parent 'clients' already present! Jun 3 03:09:44 sane4 kernel: [124345.416531] debugfs: Directory '1299' with parent 'alloc' already present! Jun 3 03:09:44 sane4 kernel: [124345.416716] debugfs: Directory '1299' with parent 'clients' already present! Jun 3 15:14:55 sane4 kernel: [167857.618213] debugfs: Directory '1299' with parent 'alloc' already present! Jun 3 15:14:55 sane4 kernel: [167857.618382] debugfs: Directory '1299' with parent 'clients' already present! Jun 4 06:26:21 sane4 kernel: [222544.081034] debugfs: Directory '18792' with parent 'alloc' already present! Jun 4 06:26:21 sane4 kernel: [222544.084183] debugfs: Directory '18792' with parent 'clients' already present! Jun 4 06:33:31 sane4 kernel: [222974.294878] debugfs: Directory '18792' with parent 'alloc' already present! Jun 4 06:33:31 sane4 kernel: [222974.295093] debugfs: Directory '18792' with parent 'clients' already present! Jun 4 07:18:27 sane4 kernel: [225669.891203] debugfs: Directory '18792' with parent 'alloc' already present! Jun 4 07:18:27 sane4 kernel: [225669.891500] debugfs: Directory '18792' with parent 'clients' already present! Jun 4 12:00:31 sane4 kernel: [242594.080243] debugfs: Directory '18792' with parent 'alloc' already present! Jun 4 12:00:31 sane4 kernel: [242594.080412] debugfs: Directory '18792' with parent 'clients' already present! Jun 4 13:20:25 sane4 kernel: [247388.210624] debugfs: Directory '18792' with parent 'alloc' already present! Jun 4 13:20:25 sane4 kernel: [247388.210982] debugfs: Directory '18792' with parent 'clients' already present!

Again the process 18792 also belongs to chromium-browser, I have not noticed anything untoward happening, but it only started when the kernel version was bumped up to 5. I know very little about these things, but it was suggested I post the information here, so that minds immeasurably superior to mine could ponder the implications.

[pelwell]

so that minds immeasurably superior to mine could ponder the implications

If only there were some.

[jbeale1]

I just got 104 lines in my 'dmesg' output of the form:
[ 7179.245765] debugfs: Directory '1098' with parent 'clients' already present!

I don't remember this happening before. Process 1098 is the chromium browser.
$ ps aux | grep 1098
pi 1098 5.1 7.9 1194316 311668 ? Sl Apr24 40:00 /usr/lib/chromium-browser/chromium-browser-v7 --force-renderer-accessibility --disable-quic --enable-tcp-fast-open --check-for-update-interval=31536000 --enable-pinch --disable-features=AudioServiceOutOfProcess

$ uname -a
Linux rp49 5.10.17-v7l+ #1403 SMP Mon Feb 22 11:33:35 GMT 2021 armv7l GNU/Linux

It may be related to viewing a PDF in the browser, I had recently been viewing https://hackspace.raspberrypi.org/issues/15/pdf