Karol Herbst
2023-Feb-18 12:25 UTC
[Nouveau] linux-6.2-rc4+ hangs on poweroff/reboot: Bisected
On Sat, Feb 18, 2023 at 1:22 PM Chris Clayton <chris2553 at googlemail.com> wrote:> > > > On 15/02/2023 11:09, Karol Herbst wrote: > > On Wed, Feb 15, 2023 at 11:36 AM Linux regression tracking #update > > (Thorsten Leemhuis) <regressions at leemhuis.info> wrote: > >> > >> On 13.02.23 10:14, Chris Clayton wrote: > >>> On 13/02/2023 02:57, Dave Airlie wrote: > >>>> On Sun, 12 Feb 2023 at 00:43, Chris Clayton <chris2553 at googlemail.com> wrote: > >>>>> > >>>>> > >>>>> > >>>>> On 10/02/2023 19:33, Linux regression tracking (Thorsten Leemhuis) wrote: > >>>>>> On 10.02.23 20:01, Karol Herbst wrote: > >>>>>>> On Fri, Feb 10, 2023 at 7:35 PM Linux regression tracking (Thorsten > >>>>>>> Leemhuis) <regressions at leemhuis.info> wrote: > >>>>>>>> > >>>>>>>> On 08.02.23 09:48, Chris Clayton wrote: > >>>>>>>>> > >>>>>>>>> I'm assuming that we are not going to see a fix for this regression before 6.2 is released. > >>>>>>>> > >>>>>>>> Yeah, looks like it. That's unfortunate, but happens. But there is still > >>>>>>>> time to fix it and there is one thing I wonder: > >>>>>>>> > >>>>>>>> Did any of the nouveau developers look at the netconsole captures Chris > >>>>>>>> posted more than a week ago to check if they somehow help to track down > >>>>>>>> the root of this problem? > >>>>>>> > >>>>>>> I did now and I can't spot anything. I think at this point it would > >>>>>>> make sense to dump the active tasks/threads via sqsrq keys to see if > >>>>>>> any is in a weird state preventing the machine from shutting down. > >>>>>> > >>>>>> Many thx for looking into it! > >>>>> > >>>>> Yes, thanks Karol. > >>>>> > >>>>> Attached is the output from dmesg when this block of code: > >>>>> > >>>>> /bin/mount /dev/sda7 /mnt/sda7 > >>>>> /bin/mountpoint /proc || /bin/mount /proc > >>>>> /bin/dmesg -w > /mnt/sda7/sysrq.dmesg.log & > >>>>> /bin/echo t > /proc/sysrq-trigger > >>>>> /bin/sleep 1 > >>>>> /bin/sync > >>>>> /bin/sleep 1 > >>>>> kill $(pidof dmesg) > >>>>> /bin/umount /mnt/sda7 > >>>>> > >>>>> is executed immediately before /sbin/reboot is called as the final step of rebooting my system. > >>>>> > >>>>> I hope this is what you were looking for, but if not, please let me know what you need > >>> > >>> Thanks Dave. [...] > >> FWIW, in case anyone strands here in the archives: the msg was > >> truncated. The full post can be found in a new thread: > >> > >> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ > >> > >> Sadly it seems the info "With runpm=0, both reboot and poweroff work on > >> my laptop." didn't bring us much further to a solution. :-/ I don't > >> really like it, but for regression tracking I'm now putting this on the > >> back-burner, as a fix is not in sight. > >> > >> #regzbot monitor: > >> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ > >> #regzbot backburner: hard to debug and apparently rare > >> #regzbot ignore-activity > >> > > > > yeah.. this bug looks a little annoying. Sadly the only Turing based > > laptop I got doesn't work on Nouveau because of firmware related > > issues and we probably need to get updated ones from Nvidia here :( > > > > But it's a bit weird that the kernel doesn't shutdown, because I don't > > see anything in the logs which would prevent that from happening. > > Unless it's waiting on one of the tasks to complete, but none of them > > looked in any way nouveau related. > > > > If somebody else has any fancy kernel debugging tips here to figure > > out why it hangs, that would be very helpful... > > > > I think I've figured this out. It's to do with how my system is configured. I do have an initrd, but the only thing on > it is the cpu microcode which, it is recommended, should be loaded early. The absence of the NVidia firmare from an > initrd doesn't matter because the drivers for the hardware that need to load firmware are all built as modules, So, by > the time the devices are configured via udev, the root partition is mounted and the drivers can get at the firmware. > > I've found, by turning on nouveau debug and taking a video of the screen as the system shuts down, that nouveau seems to > be trying to run the scrubber very very late in the shutdown process. The problem is that by this time, I think the root > partition, and thus the scrubber binary, have become inaccessible. > > I seem to have two choices - either make the firmware accessible on an initrd or unload the module in a shutdown script > before the scrubber binary becomes inaccessible. The latter of these is the workaround I have implemented whilst the > problem I reported has been under investigation. For simplicity, I think I'll promote my workaround to being the > permanent solution. > > So, apologies (and thanks) to everyone whose time I have taken up with this non-bug. >Well.. nouveau shouldn't prevent the system from shutting down if the firmware file isn't available. Or at least it should print a warning/error. Mind messing with the code a little to see if skipping it kind of works? I probably can also come up with a patch by next week.> Chris > > >> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > >> -- > >> Everything you wanna know about Linux kernel regression tracking: > >> https://linux-regtracking.leemhuis.info/about/#tldr > >> That page also explains what to do if mails like this annoy you. > >> > >> #regzbot ignore-activity > >> > > >
Chris Clayton
2023-Feb-18 15:19 UTC
[Nouveau] linux-6.2-rc4+ hangs on poweroff/reboot: Bisected
On 18/02/2023 12:25, Karol Herbst wrote:> On Sat, Feb 18, 2023 at 1:22 PM Chris Clayton <chris2553 at googlemail.com> wrote: >> >> >> >> On 15/02/2023 11:09, Karol Herbst wrote: >>> On Wed, Feb 15, 2023 at 11:36 AM Linux regression tracking #update >>> (Thorsten Leemhuis) <regressions at leemhuis.info> wrote: >>>> >>>> On 13.02.23 10:14, Chris Clayton wrote: >>>>> On 13/02/2023 02:57, Dave Airlie wrote: >>>>>> On Sun, 12 Feb 2023 at 00:43, Chris Clayton <chris2553 at googlemail.com> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 10/02/2023 19:33, Linux regression tracking (Thorsten Leemhuis) wrote: >>>>>>>> On 10.02.23 20:01, Karol Herbst wrote: >>>>>>>>> On Fri, Feb 10, 2023 at 7:35 PM Linux regression tracking (Thorsten >>>>>>>>> Leemhuis) <regressions at leemhuis.info> wrote: >>>>>>>>>> >>>>>>>>>> On 08.02.23 09:48, Chris Clayton wrote: >>>>>>>>>>> >>>>>>>>>>> I'm assuming that we are not going to see a fix for this regression before 6.2 is released. >>>>>>>>>> >>>>>>>>>> Yeah, looks like it. That's unfortunate, but happens. But there is still >>>>>>>>>> time to fix it and there is one thing I wonder: >>>>>>>>>> >>>>>>>>>> Did any of the nouveau developers look at the netconsole captures Chris >>>>>>>>>> posted more than a week ago to check if they somehow help to track down >>>>>>>>>> the root of this problem? >>>>>>>>> >>>>>>>>> I did now and I can't spot anything. I think at this point it would >>>>>>>>> make sense to dump the active tasks/threads via sqsrq keys to see if >>>>>>>>> any is in a weird state preventing the machine from shutting down. >>>>>>>> >>>>>>>> Many thx for looking into it! >>>>>>> >>>>>>> Yes, thanks Karol. >>>>>>> >>>>>>> Attached is the output from dmesg when this block of code: >>>>>>> >>>>>>> /bin/mount /dev/sda7 /mnt/sda7 >>>>>>> /bin/mountpoint /proc || /bin/mount /proc >>>>>>> /bin/dmesg -w > /mnt/sda7/sysrq.dmesg.log & >>>>>>> /bin/echo t > /proc/sysrq-trigger >>>>>>> /bin/sleep 1 >>>>>>> /bin/sync >>>>>>> /bin/sleep 1 >>>>>>> kill $(pidof dmesg) >>>>>>> /bin/umount /mnt/sda7 >>>>>>> >>>>>>> is executed immediately before /sbin/reboot is called as the final step of rebooting my system. >>>>>>> >>>>>>> I hope this is what you were looking for, but if not, please let me know what you need >>>>> >>>>> Thanks Dave. [...] >>>> FWIW, in case anyone strands here in the archives: the msg was >>>> truncated. The full post can be found in a new thread: >>>> >>>> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ >>>> >>>> Sadly it seems the info "With runpm=0, both reboot and poweroff work on >>>> my laptop." didn't bring us much further to a solution. :-/ I don't >>>> really like it, but for regression tracking I'm now putting this on the >>>> back-burner, as a fix is not in sight. >>>> >>>> #regzbot monitor: >>>> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ >>>> #regzbot backburner: hard to debug and apparently rare >>>> #regzbot ignore-activity >>>> >>> >>> yeah.. this bug looks a little annoying. Sadly the only Turing based >>> laptop I got doesn't work on Nouveau because of firmware related >>> issues and we probably need to get updated ones from Nvidia here :( >>> >>> But it's a bit weird that the kernel doesn't shutdown, because I don't >>> see anything in the logs which would prevent that from happening. >>> Unless it's waiting on one of the tasks to complete, but none of them >>> looked in any way nouveau related. >>> >>> If somebody else has any fancy kernel debugging tips here to figure >>> out why it hangs, that would be very helpful... >>> >> >> I think I've figured this out. It's to do with how my system is configured. I do have an initrd, but the only thing on >> it is the cpu microcode which, it is recommended, should be loaded early. The absence of the NVidia firmare from an >> initrd doesn't matter because the drivers for the hardware that need to load firmware are all built as modules, So, by >> the time the devices are configured via udev, the root partition is mounted and the drivers can get at the firmware. >> >> I've found, by turning on nouveau debug and taking a video of the screen as the system shuts down, that nouveau seems to >> be trying to run the scrubber very very late in the shutdown process. The problem is that by this time, I think the root >> partition, and thus the scrubber binary, have become inaccessible. >> >> I seem to have two choices - either make the firmware accessible on an initrd or unload the module in a shutdown script >> before the scrubber binary becomes inaccessible. The latter of these is the workaround I have implemented whilst the >> problem I reported has been under investigation. For simplicity, I think I'll promote my workaround to being the >> permanent solution. >> >> So, apologies (and thanks) to everyone whose time I have taken up with this non-bug. >> > > Well.. nouveau shouldn't prevent the system from shutting down if the > firmware file isn't available. Or at least it should print a > warning/error. Mind messing with the code a little to see if skipping > it kind of works? I probably can also come up with a patch by next > week. >Well, I'd love to but a quick glance at the code caused me to bump into this obscenity: int gm200_flcn_reset_wait_mem_scrubbing(struct nvkm_falcon *falcon) { nvkm_falcon_mask(falcon, 0x040, 0x00000000, 0x00000000); if (nvkm_msec(falcon->owner->device, 10, if (!(nvkm_falcon_rd32(falcon, 0x10c) & 0x00000006)) break; ) < 0) return -ETIMEDOUT; return 0; } nvkm_msec is #defined to nvkm_usec which in turn is #defined to nvkm_nsec where the loop that the break is related to appears.> Chris>> >>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) >>>> -- >>>> Everything you wanna know about Linux kernel regression tracking: >>>> https://linux-regtracking.leemhuis.info/about/#tldr >>>> That page also explains what to do if mails like this annoy you. >>>> >>>> #regzbot ignore-activity >>>> >>> >> >
Chris Clayton
2023-Feb-18 18:55 UTC
[Nouveau] linux-6.2-rc4+ hangs on poweroff/reboot: Bisected
On 18/02/2023 15:19, Chris Clayton wrote:> > > On 18/02/2023 12:25, Karol Herbst wrote: >> On Sat, Feb 18, 2023 at 1:22 PM Chris Clayton <chris2553 at googlemail.com> wrote: >>> >>> >>> >>> On 15/02/2023 11:09, Karol Herbst wrote: >>>> On Wed, Feb 15, 2023 at 11:36 AM Linux regression tracking #update >>>> (Thorsten Leemhuis) <regressions at leemhuis.info> wrote: >>>>> >>>>> On 13.02.23 10:14, Chris Clayton wrote: >>>>>> On 13/02/2023 02:57, Dave Airlie wrote: >>>>>>> On Sun, 12 Feb 2023 at 00:43, Chris Clayton <chris2553 at googlemail.com> wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On 10/02/2023 19:33, Linux regression tracking (Thorsten Leemhuis) wrote: >>>>>>>>> On 10.02.23 20:01, Karol Herbst wrote: >>>>>>>>>> On Fri, Feb 10, 2023 at 7:35 PM Linux regression tracking (Thorsten >>>>>>>>>> Leemhuis) <regressions at leemhuis.info> wrote: >>>>>>>>>>> >>>>>>>>>>> On 08.02.23 09:48, Chris Clayton wrote: >>>>>>>>>>>> >>>>>>>>>>>> I'm assuming that we are not going to see a fix for this regression before 6.2 is released. >>>>>>>>>>> >>>>>>>>>>> Yeah, looks like it. That's unfortunate, but happens. But there is still >>>>>>>>>>> time to fix it and there is one thing I wonder: >>>>>>>>>>> >>>>>>>>>>> Did any of the nouveau developers look at the netconsole captures Chris >>>>>>>>>>> posted more than a week ago to check if they somehow help to track down >>>>>>>>>>> the root of this problem? >>>>>>>>>> >>>>>>>>>> I did now and I can't spot anything. I think at this point it would >>>>>>>>>> make sense to dump the active tasks/threads via sqsrq keys to see if >>>>>>>>>> any is in a weird state preventing the machine from shutting down. >>>>>>>>> >>>>>>>>> Many thx for looking into it! >>>>>>>> >>>>>>>> Yes, thanks Karol. >>>>>>>> >>>>>>>> Attached is the output from dmesg when this block of code: >>>>>>>> >>>>>>>> /bin/mount /dev/sda7 /mnt/sda7 >>>>>>>> /bin/mountpoint /proc || /bin/mount /proc >>>>>>>> /bin/dmesg -w > /mnt/sda7/sysrq.dmesg.log & >>>>>>>> /bin/echo t > /proc/sysrq-trigger >>>>>>>> /bin/sleep 1 >>>>>>>> /bin/sync >>>>>>>> /bin/sleep 1 >>>>>>>> kill $(pidof dmesg) >>>>>>>> /bin/umount /mnt/sda7 >>>>>>>> >>>>>>>> is executed immediately before /sbin/reboot is called as the final step of rebooting my system. >>>>>>>> >>>>>>>> I hope this is what you were looking for, but if not, please let me know what you need >>>>>> >>>>>> Thanks Dave. [...] >>>>> FWIW, in case anyone strands here in the archives: the msg was >>>>> truncated. The full post can be found in a new thread: >>>>> >>>>> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ >>>>> >>>>> Sadly it seems the info "With runpm=0, both reboot and poweroff work on >>>>> my laptop." didn't bring us much further to a solution. :-/ I don't >>>>> really like it, but for regression tracking I'm now putting this on the >>>>> back-burner, as a fix is not in sight. >>>>> >>>>> #regzbot monitor: >>>>> https://lore.kernel.org/lkml/e0b80506-b3cf-315b-4327-1b988d86031e at googlemail.com/ >>>>> #regzbot backburner: hard to debug and apparently rare >>>>> #regzbot ignore-activity >>>>> >>>> >>>> yeah.. this bug looks a little annoying. Sadly the only Turing based >>>> laptop I got doesn't work on Nouveau because of firmware related >>>> issues and we probably need to get updated ones from Nvidia here :( >>>> >>>> But it's a bit weird that the kernel doesn't shutdown, because I don't >>>> see anything in the logs which would prevent that from happening. >>>> Unless it's waiting on one of the tasks to complete, but none of them >>>> looked in any way nouveau related. >>>> >>>> If somebody else has any fancy kernel debugging tips here to figure >>>> out why it hangs, that would be very helpful... >>>> >>> >>> I think I've figured this out. It's to do with how my system is configured. I do have an initrd, but the only thing on >>> it is the cpu microcode which, it is recommended, should be loaded early. The absence of the NVidia firmare from an >>> initrd doesn't matter because the drivers for the hardware that need to load firmware are all built as modules, So, by >>> the time the devices are configured via udev, the root partition is mounted and the drivers can get at the firmware. >>> >>> I've found, by turning on nouveau debug and taking a video of the screen as the system shuts down, that nouveau seems to >>> be trying to run the scrubber very very late in the shutdown process. The problem is that by this time, I think the root >>> partition, and thus the scrubber binary, have become inaccessible. >>> >>> I seem to have two choices - either make the firmware accessible on an initrd or unload the module in a shutdown script >>> before the scrubber binary becomes inaccessible. The latter of these is the workaround I have implemented whilst the >>> problem I reported has been under investigation. For simplicity, I think I'll promote my workaround to being the >>> permanent solution. >>> >>> So, apologies (and thanks) to everyone whose time I have taken up with this non-bug. >>> >> >> Well.. nouveau shouldn't prevent the system from shutting down if the >> firmware file isn't available. Or at least it should print a >> warning/error. Mind messing with the code a little to see if skipping >> it kind of works? I probably can also come up with a patch by next >> week. >> > Well, I'd love to but a quick glance at the code caused me to bump into this obscenity: > > int > gm200_flcn_reset_wait_mem_scrubbing(struct nvkm_falcon *falcon) > { > nvkm_falcon_mask(falcon, 0x040, 0x00000000, 0x00000000); > > if (nvkm_msec(falcon->owner->device, 10, > if (!(nvkm_falcon_rd32(falcon, 0x10c) & 0x00000006)) > break; > ) < 0) > return -ETIMEDOUT; > > return 0; > } > > nvkm_msec is #defined to nvkm_usec which in turn is #defined to nvkm_nsec where the loop that the break is related to > appearsI think someone who knows the code needs to look at this. What I can confirm is that after a freeze, I waited for 90 seconds for a timeout to occur, but it didn't. .> Chris>>> >>>>> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) >>>>> -- >>>>> Everything you wanna know about Linux kernel regression tracking: >>>>> https://linux-regtracking.leemhuis.info/about/#tldr >>>>> That page also explains what to do if mails like this annoy you. >>>>> >>>>> #regzbot ignore-activity >>>>> >>>> >>> >>